Background: The effect of amylases combined with exogenous carbohydrase and protease in a newly harvested corn diet on starch digestibility, intestine health and cecal microbiota was investigated in broiler chickens.M...Background: The effect of amylases combined with exogenous carbohydrase and protease in a newly harvested corn diet on starch digestibility, intestine health and cecal microbiota was investigated in broiler chickens.Methods: Two hunderd and eighty-eight 5-day-old female chickens were randomly divided into six treatments: a newly harvested corn-soybean meal diet(control); control supplemented with 1,500 U/g α-amylase(Enzyme A);Enzyme A + 300 U/g amylopectase + 20,000 U/g glucoamylase(Enzyme B); Enzyme B + protease 10,000 U/g(Enzyme C); Enzyme C + xylanase 15,000 U/g(Enzyme D); and Enzyme D + cellulase 200 U/g + pectinase 1,000 U/g(Enzyme E). Growth performance, starch digestibility, digestive organ morphology, and intestinal microbiota were evaluated in the birds at 16 and 23 d of age.Results: Compared with the control diet, supplementation with Enzyme A significantly decreased ileum lesion scoring at 16 d of age(P < 0.05); supplementation with Enzyme B or Enzyme C showed positive effects on ileal amylopectin and total starch digestibility(P < 0.05); Broilers fed with a diet supplemented with Enzyme D had a tendency to decrease body weight gain at 23 d. Enzyme E supplementation improved lesion scoring of jejunum and ileum at 16 d(P < 0.05), and increased ileal amylopectin or total starch digestibility at 23 d(P < 0.05).Supplementation of enzymes changed cecal microbiota diversity. High numbers of Campylobacter, Helicobacter and Butyricicoccus, Anaerostipes and Bifidobacterium, Sutterella and Odoribacter were the main genera detected in supplementations with Enzymes B, C, D, and E respectively.Conclusions: Supplementation with amylase combined with glucoamylase or protease showed a beneficial effect on starch digestibility and intestinal microbiota diversity, and increased growth of broilers fed with newly harvested corn.展开更多
Two rice varieties, Xiushui 110 with high cadmium (Cd) tolerance and Xiushui 11 with low Cd tolerance were used to study the effects of Cd stress on seed germination, seedling growth and amylase activities. The low ca...Two rice varieties, Xiushui 110 with high cadmium (Cd) tolerance and Xiushui 11 with low Cd tolerance were used to study the effects of Cd stress on seed germination, seedling growth and amylase activities. The low cadmium concentration had little effect on seed germination rate. However, cadmium stress could significantly inhibit plumule and radicle growth, especially for radicle growth. Germination index, vigour index, radicle length and amylase activities of Xiushui 11 decreased more significantly with the increasing cadmium level compared with Xiushui 110. The cadmium content in seedlings of Xiushui 11 was higher than that in Xiushui 110 when the cadmium concentration exceeded 5 μmol/L, which caused lower mitotic index in root tips and amylase activities, and more serious cadmium toxicity in Xiushui 11.展开更多
Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies.α-Glucosidase and α-amylase are the crucial factors in regulating starch digestion a...Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies.α-Glucosidase and α-amylase are the crucial factors in regulating starch digestion and glucose absorption,making them key targets for many studies to treat postprandial hyperglycemia.We studied the inhibitory activities of microalgal fucoxanthin against rat-intestinalα-glucosidase and pancreaticα-amylase along with the antidiabetic eff ect to induce diff erentiation in 3T3-L1 pre-adipocytes using Oil Red-O staining.Fucoxanthin displayed strong hindrance activities towardα-amylase in a concentration-dependent manner,with an IC50 value of 0.68mmol/L,whereas weak inhibitory activity against α-glucosidase,with an IC 50 value of 4.75 mmol/L.Fucoxanthin also considerably elevated glucose oxidase activity in 3T3-L1 cells by 31.3%at 5μmol/L.During adipocyte differentiation,fucoxanthin showed lipid accumulation in 3T3-L1 cells with no cytotoxicity up to 20μmol/L.However,fucoxanthin had no inhibitory activity on glucose-6-phosphate dehydrogenase.These results suggest that fucoxanthin might be useful for the prevention of obesity or diabetes by inhibiting carbohydrate-hydrolyzing enzymes and lipid accumulation and be utilized as an ingredient for a functional food or dietary supplement.展开更多
The marine yeast strain N13d, producing an extracellular amylase, was isolated from the deep sea sediments of the Pa-cific Ocean. This strain was identified to be Aureobasidium pullulans by 18S rRNA gene sequence anal...The marine yeast strain N13d, producing an extracellular amylase, was isolated from the deep sea sediments of the Pa-cific Ocean. This strain was identified to be Aureobasidium pullulans by 18S rRNA gene sequence analysis and routine yeast identi-fication methods. The optimal sea water medium for amylase production by this yeast strain was 1.0% peptone and 1.0% soluble starch with pH 4.0. The optimal conditions for amylase production by this yeast strain were with temperature 28 ℃, aeration rate 6 Lmin-1 and agitation speed 250 rmin-1. Under these conditions, 58.5 units of amylase activity per mg protein were produced within 56 h of fermentation.展开更多
BACKGROUND: Measurement of total serum amylase (AMY) is the most widely used biochemical test for the diagnosis of acute pancreatitis, but it is commonly considered a nonspecific marker. To improve the biochemical dia...BACKGROUND: Measurement of total serum amylase (AMY) is the most widely used biochemical test for the diagnosis of acute pancreatitis, but it is commonly considered a nonspecific marker. To improve the biochemical diagnosis of acute pancreatitis, lipase ( LIP ) and pancreatic amylase (PAMY) have been tested in recent years. The present study was designed to evaluate whether serum LIP and pancreatic PAMY tests could replace total amylase test to improve diagnostic efficiency in the evaluation of acute pancreatitis in patients with hyperamylasemia. METHODS: LIP and PAMY values were determined in serum samples from 92 patients with hyperamylasemia. Reference values for each enzyme were derived from serum samples of 147 healthy subjects. The activities of LIP and PAMY in patients with various diseases were shown directly by the boxplot graph. The diagnostic accuracy of LIP and PAMY was defined as the area under the receiver operating characteristic (ROC) curve. Their sensitivity and specificity in detecting acute pancreatitis at varying cutoff points were shown by the curve, and the best cutoff value for each enzyme was shown by the modified ROC curve. The diagnostic values of LIP, PAMY and LIP + AMY with each upper limit of reference range (ULR) were compared with the corresponding best cutoff values. RESULTS: The references values of LIP and PAMY were 12.2-47.6 U/L and 28-95 U/L, respectively. These values in patients with acute pancreatitis were higher than those patients with other diseases. The areas under the ROC curve ( AUC) of LIP and PAMY were 0. 799 and 0. 792, respectively, With the best diagnostic cutoff point of maximum (sensitivity + specificity) -100%, we obtained values of 97.9 U/L(LIP97.9 =2. 06 × ULR) for LIP and 209 U/L (PAMY209 =2.20 ×ULR) for PAMY. The best cutoff values for LIP, PAMY and LIP +AMY demonstrated the specificity, positive predictive value, and diagnostic efficiency higher than the corresponding ULRs. CONCLUSIONS: Serum LIP and PAMY are specific for the pancreas and might replace total amylase for the diagnosis of acute pancreatitis in hyperamylasemia patients. LIP97.9 is more efficient than PAMY209 in the diagnosis of acute pancreatitis. A combined test of both enzymes is not superior to single test of either enzyme in diagnostic accuracy.展开更多
For the last decade, low serum amylase(hypoamylasemia) has been reported in certain common cardiometabolic conditions such as obesity, diabetes(regardless of type), and metabolic syndrome, all of which appear to have ...For the last decade, low serum amylase(hypoamylasemia) has been reported in certain common cardiometabolic conditions such as obesity, diabetes(regardless of type), and metabolic syndrome, all of which appear to have a common etiology of insufficient insulin action due to insulin resistance and/or diminished insulin secretion. Some clinical studies have shown that salivary amylase may be preferentially decreased in obese individuals, whereas others have revealed that pancreatic amylase may be preferentially decreased in diabetic subjects with insulin dependence. Despite this accumulated evidence, the clinical relevance of serum, salivary, and pancreatic amylase and the underlying mechanisms have not been fully elucidated. In recent years, copy number variations(CNVs) in the salivary amylase gene(AMY1), which range more broadly than the pancreatic amylase gene(AMY2A and AMY2B), have been shown to be well correlated with salivary and serum amylase levels. In addition, low CNV of AMY1, indicating low salivary amylase, was associated with insulin resistance, obesity, low taste perception/satiety, and postprandial hyperglycemia through impaired insulin secretion at early cephalic phase. In most populations, insulin-dependent diabetes is less prevalent(minor contribution) compared with insulin-independent diabetes, and obesity is highly prevalent compared with low body weight. Therefore, obesity as a condition that elicits cardiometabolic diseases relating to insulin resistance(major contribution) may be a common determinant for low serum amylase in a general population. In this review, the novel interpretation of low serum, salivary, and pancreas amylase is discussed in terms of major contributions of obesity, diabetes, and metabolic syndrome.展开更多
AIM To estimate the efficacy of 2 h post-endoscopic retrograde cholangiopancreatography(ERCP) serum amylase levels and other factors for predicting postERCP pancreatitis.METHODS This was a retrospective,single-center ...AIM To estimate the efficacy of 2 h post-endoscopic retrograde cholangiopancreatography(ERCP) serum amylase levels and other factors for predicting postERCP pancreatitis.METHODS This was a retrospective,single-center cohort study of consecutive patients who underwent ERCP from January 2010 to December 2013.Serum amylase levels were measured 2 h post-procedure,and patient- and procedure-related pancreatitis(PEP) risk factors wereanalyzed using a logistic model.RESULTS A total of 1520 cases(average age 72 ± 12 years,60% male) were initially enrolled in this study,and 1403 cases(725 patients) were ultimately analyzed after the exclusion of 117 cases.Fifty-five of these cases developed PEP.We established a 2 h serum amylase cutoff level of two times the upper limit of normal for predicting PEP.Multivariate analysis revealed that a cannulation time of more than 13 min [odds ratio(OR) 2.28,95%CI:1.132-4.651,P=0.0210] and 2 h amylase levels greater than the cutoff level(OR=24.1,95%CI:11.56-57.13,P<0.0001) were significant predictive factors for PEP.Forty-seven of the 55 patients who developed PEP exhibited 2 h amylase levels greater than the cutoff level(85%),and six of the remaining eight patients who developed PEP(75%) required longer cannulation times.Only 2 of the 1403 patients(0.14%) who developed PEP did not exhibit concerning 2 h amylase levels or require longer cannulation times.CONCLUSION These findings indicate that the combination of 2 h post-ERCP serum amylase levels and cannulation times represents a valuable marker for identifying patients at high risk for PEP.展开更多
AIM:To investigate the value of elevated drain amylase concentrations for detecting anastomotic leakage(AL) after minimally invasive Ivor-Lewis esophagectomy(MIILE).METHODS:This was a retrospective analysis of prospec...AIM:To investigate the value of elevated drain amylase concentrations for detecting anastomotic leakage(AL) after minimally invasive Ivor-Lewis esophagectomy(MIILE).METHODS:This was a retrospective analysis of prospectively collected data in two hospitals in the Netherlands. Consecutive patients undergoing MI-ILE were included. A Jackson-Pratt drain next to the dorsal side of the anastomosis and bilateral chest drains were placed at the end of the thoracoscopic procedure. Amylase levels in drain fluid were determined in all patients during at least the first four postoperative days. Contrast computed tomography scans and/or endoscopic imaging were performed in cases of a clinically suspected AL. Anastomotic leakage was defined as any sign of leakage of the esophago-gastric anastomosis on endoscopy,re-operation,radiographic investigations,post mortal examination or when gastro-intestinal contents were found in drain fluid. Receiver operator characteristic curves were used to determine the cut-off values. Sensitivity,specificity,positive predictive value,negative predictive value,risk ratio and overall test accuracy were calculated for elevated drain amylase concentrations.RESULTS:A t o t a l o f 8 9 p a t ie n t s w e re in c lu d e d between March 2013 and August 2014. No differences in group characteristics were observed between patients with and without AL,except for age. Patients with AL were older than were patients without AL(P = 0.01). One patient(1.1%) without AL died within 30 d after surgery due to pneumonia and acute respiratory distress syndrome. Anastomotic leakage that required any intervention occurred in 15 patients(16.9%). Patients with proven anastomotic leakage had higher drain amylase levels than patients without anastomotic leakage [median 384 IU/L(IQR 34-6263) vs median 37 IU/L(IQR 26-66),P = 0.003]. Optimal cut-off values on postoperative days 1,2,and 3 were 350 IU/L,200 IU/L and 160 IU/L,respectively. An elevated amylase level was found in 9 of the 15 patients with AL. Five of these 9 patients had early elevations of their amylase levels,with a median of 2 d(IQR 2-5) before signs and symptoms occurred.CONCLUSION:Measurement of drain amylase levels is an inexpensive and easy tool that may be used to screen for anastomotic leakage soon after MI-ILE. However,clinical validation of this marker is necessary.展开更多
Many studies investigating postoperative pancreatic fistula(POPF)after gastrectomy,including studies measuring drain amylase content(D-AMY)as a predictive factor have been reported.This article reviews previous studie...Many studies investigating postoperative pancreatic fistula(POPF)after gastrectomy,including studies measuring drain amylase content(D-AMY)as a predictive factor have been reported.This article reviews previous studies and looks to the future of measuring D-AMY in patients after gastrectomy.The causes of pancreatic fluid leakage are;the parenchymal and/or thermal injury to the pancreas,and blunt injury to the pancreas by compression and retraction.Measurement of D-AMY to predict POPF has become common in clinical practice after pancreatic surgery and was later extended to the gastric surgery.Several studies have reported associations between D-AMY and POPF after gastrectomy,and the high value of D-AMY on postoperative day(POD)1 was an independent risk factor.To improve both sensitivity and specificity,attempts have been made to enhance the predictive accuracy of factors on POD 1 as well as on POD 3 as combined markers.Although several studies have shown a high predictive ability of POPF,it has not necessarily been exploited in clinical practice.Many problems remain unresolved;ideal timing for measurement,optimal cut-off value,and means of intervention after prediction.Prospective clinical trial could be imperative in order to develop D-AMY measurement in common clinical practice for gastric surgery.展开更多
BACKGROUND Hypothyroidism is an endocrine disorder that has worldwide prevalence and can affect multiple organ systems.We report a case of hypothyroidism with elevated pancreatic amylase and trypsin without acute panc...BACKGROUND Hypothyroidism is an endocrine disorder that has worldwide prevalence and can affect multiple organ systems.We report a case of hypothyroidism with elevated pancreatic amylase and trypsin without acute pancreatitis.No such case has been previously reported.CASE SUMMARY A 29-year-old woman did not pay much attention to a fever 4 d prior.During this time,she experienced anorexia and only drank a small amount of water every day.She did not present with abdominal distension,postprandial nausea,vomiting,cough or expectoration.After physical and laboratory examinations,the patient was diagnosed with hypothyroidism.During the course of the disease,hypothyroidism was generally accompanied by constantly increased pancreatic amylase and trypsin.After admission,the possible etiology of the patient was excluded and the concentrations of pancreatic lipase and amylase in serum were>2000U/L(reference range 23-300 U/L)and 410 U/L(reference range 30-110 U/L),respectively.So we highly suspected that it may be acute pancreatitis.Interestingly,she never developed any complications associated with acute pancreatitis despite high levels of serum pancreatic amylase and trypsin,and she reported no symptoms of abdominal pain.Serum amylase and lipase decreased gradually after active thyroxine supplementation,and the patient was discharged from the hospital after active treatment.CONCLUSION This case suggests that clinicians should pay attention to hypothyroidism with elevated pancreatic amylase and trypsin,even if no complications of acute pancreatitis are reported.展开更多
Based on the different hydrophobicities of the intermediates of proteins the various conformational intermediates of the refolding of a-amylase originally denatured with 8.0 mol/L urea solution were separated with hig...Based on the different hydrophobicities of the intermediates of proteins the various conformational intermediates of the refolding of a-amylase originally denatured with 8.0 mol/L urea solution were separated with high performance hydrophobic interaction chromatography(HPHIC). Compared to the separation of the same intermediates with weak anion exchange chromatography and size-exclusion chromatography the result obtained with HPHIC is the best It would be expected that HPHIC may be a strongly potential tool to separate intermediates of some proteins which cannot be, or cannot completely be refolded by HPHIC.展开更多
In order to obtain pure enzyme with high activity,two amylase producing strains were isolated from soil samples,and named as the strains LZ-10 and LZ-11.According to morphologic observation,physiology and biochemistry...In order to obtain pure enzyme with high activity,two amylase producing strains were isolated from soil samples,and named as the strains LZ-10 and LZ-11.According to morphologic observation,physiology and biochemistry experiments,16S rRNA and gyrB gene analysis,the strains LZ-10 and LZ-11 were identified as Bacillus subtilis.Adopted the method of ammonium sulfate,DEAE-52 anion purify enzyme,finally used polyacrylamide gel electrophoresis(SDS-PAGE)to detect molecular weight.The strain LZ-10 had an amylase activity of 123.3 U·mL^(-1),a purification factor of 6.8,a recovery rate of 69.5% and an optimal temperature of 50℃.The amylase activity of the strain LZ-11 was 59.91 U·mL^(-1),the purification factor was 4.5,the recovery rate was 60.5%,and the optimum temperature was 55℃.The commodity enzyme derived from Bacillus subtilis was 37.5 U·mL^(-1).The relative molecular weight of amylase activity from the two strains was 55 ku.Both thermal stability and pH stability were higher than those of commercialized amylase.展开更多
Two sampling devices that allow saliva collection through absorption to a cotton roll (Salivette?-method) or to small cotton pellets (VectaSpinTM Micro [VSM]-method) were studied. Any loss of salivary alpha-amylase (s...Two sampling devices that allow saliva collection through absorption to a cotton roll (Salivette?-method) or to small cotton pellets (VectaSpinTM Micro [VSM]-method) were studied. Any loss of salivary alpha-amylase (sAA) activity in relation to the saliva volume absorbed and harvested by centrifugation was examined. A pooled saliva sample prepared from stimulated whole saliva (collected by drooling) of 30 subjects was used. Three different saliva volumes (2.9 ml, 1.5 ml, and 0.8 ml) were tested on cotton rolls and two (0.03 ml, and 0.015 ml) on cotton pellets. The sample sAA activity was determined from the hydrolysis of 2-chloro-4-nitrophenyl-α-D-maltotrioside. In comparison with the original drooling sample, no sAA loss was observed in 1.5 ml samples tested with Salivette, while a significant decrease of activity was recorded with smaller volumes. VSM collected samples showed a non-volume dependent decrease of sAA activity of about 25%. Salivette requires large saliva volumes to allow an accurate sAA estimation. With cases of limited saliva access, VSM may be a suitable sampling device.展开更多
<strong>Background:</strong> Geophagy is the consumption of earth materials which occurs across several cultures. For several reasons, pregnant women in many parts of West Africa including Nigeria frequent...<strong>Background:</strong> Geophagy is the consumption of earth materials which occurs across several cultures. For several reasons, pregnant women in many parts of West Africa including Nigeria frequently consume kaolin. This study was carried out to determine the influence of kaolin consumption on serum electrolytes, glucose and amylase levels of pregnant women attending antenatal clinic in a Teaching Hospital in the south east Nigeria. <strong>Methods: </strong>A total of eighty pregnant women recruited for this study were grouped as follows;Group 1, (30 geophagic pregnant women in the first trimester), Group 2 (30 geophagic pregnant women in the second trimester) and Group 3 (20 non-geophagic pregnant women that served as control). Subjects in Groups 1 and 2 were subdivided into three based on the quantity of kaolin consumed per week: group A (100 g/week), group B (150 g/week) and group C (200 g/week). Preliminary analysis of the calcium content of kaolin was carried out. Serum levels of potassium, sodium, chloride, bicarbonate, glucose and amylase of the subjects were determined. <strong>Results:</strong> Calcium level in kaolin was below the recommended daily intake in food. The concentrations of potassium in geophagic pregnant women who consumed 150 g and 200 g of kaolin per week were significantly (p < 0.05) lower in both 1<sup>st</sup> and 2<sup>nd</sup> trimester groups., There was a significant (p < 0.05) decrease in sodium concentration (132.2 ± 2.0) of the 2<sup>nd</sup> trimester pregnant women that consumed 200 g of kaolin per week. The concentrations of chloride and bicarbonate were not significantly (p > 0.05) affected in all the groups. Serum amylase concentration decreased significantly (p < 0.05) in the 1<sup>st</sup> and 2<sup>nd</sup> trimester pregnant women on 150 g and 200 g of kaolin per week, while the plasma glucose concentration was significantly (p < 0.05) elevated in the same groups. <strong>Conclusion:</strong> This study concludes that kaolin consumption in pregnant women may predispose to gestational diabetes, electrolytes imbalance and reduced intestinal enzymes activities.展开更多
Municipal waste is one of the most hazardous components of developing countries. However, enzymes do provide an eco-friendly solution in this case. Amylase is an important enzyme in food, textile and pharmaceutical in...Municipal waste is one of the most hazardous components of developing countries. However, enzymes do provide an eco-friendly solution in this case. Amylase is an important enzyme in food, textile and pharmaceutical industry and can be used for bioconversion of waste. From the municipal solid waste we have isolated an amylase producing bacteria that can grow in the irritant municipal waste and help in their bio conversation. The bacteria were identified as Cronobacter sakazakii Jor52 (C2). The optimized media for maximum amylase production after 24 h of incubation, contains 2% starch, 0.6% peptone, 0.01% CaCl2, 0.05% KCl, 0.05% MgSO4 and 0.05% K2HPO4. The crude enzyme activity and stability study revealed that the amylase is stable within the pH 6 - 8 and temperature 30°C - 40°C and give maximum activity at 37°C at pH-8.展开更多
Cassava peels are generated as waste on soils during cassava processing in many tropical countries. This work set out to isolate some microorganisms associated with cassava peel degradation and characterize amylase en...Cassava peels are generated as waste on soils during cassava processing in many tropical countries. This work set out to isolate some microorganisms associated with cassava peel degradation and characterize amylase enzymes responsible for the degradation under some physiological conditions. A total of 30 bacteria was isolated from the peels with Bacillus species occurring the most (46.5%) and Enterobacter species (13.3%) being the next. Frequencies of fungal isolations was Rhizopus sp. (35%);Aspergillus niger (25%);Aspegillus flavus (20%) and Penicillium species (20%). Bacillus cereus, Bacillus substilis Bacillus pumillus, Aspergillus niger and Apergillus flavus were selected and screened for their abilities to produce amylase. Amylase activity was highest at day 4 for B. substilis (39.4 units/ml) and A. flavus (66.1 units/ml);at day 3 for B. cereus (55.6 units/ml) and A. niger (44.6 units/ ml). While maximum amylase activity was obtained at day 6 for B. pumilus (80.2 units/ml). Optimum pH for amylases from the two fungal isolate was 6.0 (A. niger = 53.5 units/ml and A. flavus = 65.4 units/ml). While optimum pH for B.cereus (51.7 units/ ml) and B. pumilus (44.6 units/ml) was 6.5 and for B. substilis (56.1 units/ml) at pH 7.0. Amylase activities increased from 20°C to 40°C for amylase from Bacillus sp. and 20°C to 50°C for amylase from the Aspergillus sp. after which there was a decline in activities as temperature increased to 80°C. Effect of heating duration (at 70°C for 5 minutes) on the amylase showed that A. niger has the highest activity of 127 units/ml. Effect of substrate concentration on amylase activity showed that amylase form A. flavus had the highest activity of 72.2 units/ml at 0.4% substrate concentration. The implications of the findings were discussed.展开更多
Three human α-amylases exist: Amy1 (salivary amylase), Amy2A (pancreatic amylase), and Amy2B (expressed in various tissues). These amylases share a 97% - 99% amino acid sequence identity, and two potential N-glycosyl...Three human α-amylases exist: Amy1 (salivary amylase), Amy2A (pancreatic amylase), and Amy2B (expressed in various tissues). These amylases share a 97% - 99% amino acid sequence identity, and two potential N-glycosylation sites (N427 and N476) are commonly found in the C-terminal region. In general, salivary amylase is more frequently glycosylated than pancreatic amylase, and it is still uncertain why differences in the glycosylation pattern among human amylase iso-zymes occur. In this study, we found that there was no significant change of ratio of glycosylated molecules among isozymes produced by the same cultured cells, indicating that glycosylation of amylase is influenced by the type of cell producing the enzyme rather than being an inherent property of the amylase isozymes. We analyzed the glycosylation efficiency of N-glycosylation sites in recombinant Amy2A mutants produced by HEK293 cells and found that glycosylation efficiencies of N427 and N476 were 3% - 18% and 40% - 52%, respectively, indicating that the major N-glycosylation site of glycosylated Amy2A produced by HEK293 cells is N476. The difference in the glycosylation efficiency of each N-glycosylation site also seemed to contribute in part to generate different glycosylation patterns of human amylases. We also confirmed that the C-terminal region of human amylase plays a critical role in secretion, although glycosylation does not play a part in this effect.展开更多
Owing to the production of alpha, beta and gamma amylase subtypes;starch degrading microbes, especially bacteria have an invincible role in the food, fermentation, textile and paper industries. Of them, α-amylases fr...Owing to the production of alpha, beta and gamma amylase subtypes;starch degrading microbes, especially bacteria have an invincible role in the food, fermentation, textile and paper industries. Of them, α-amylases from Bacillus spp. have contributed tremendous advancements in bio-industry, especially in starch, detergent and pharmaceutical arena. Though general reviews are seen in literature on amylases, no focused review is available yet solely on α-amylases produced by Bacillus spp. Hence, this focused review on α-amylases from the genus Bacillus is designed in such a way that it should give a vivid picture on most of the aspects on bacillial α-amylases in a handy module with an industrial perspective. With a short introduction on amylases in general, α-amylases from various species of Bacillus reviewed herein encompasses production of α-amylases by submerged and solid-state fermentations;nutrients and other factors required for maximizing production;immobilization strategies for whole cells or purified enzyme;an overview on the molecular weight of the enzyme;followed by distinct sections for purification, characterisation, stability and crystal structure;and concluded with a section on industrial applications of the α-amylases from Bacillus spp.展开更多
An evaluation method was designed for reference in the experiment,which was further verified by investigating the changes of various factors,including additive amount of enzyme,washing temperature,soaking time,pH valu...An evaluation method was designed for reference in the experiment,which was further verified by investigating the changes of various factors,including additive amount of enzyme,washing temperature,soaking time,pH value and amylase source,etc.Based on tests and comparison,it is confirmed that this method can effectively and quantitatively evaluate the performance of amylase in detergents for hand dishwashing.展开更多
基金supported by the System for Poultry Production Technology,Beijing Innovation Research Team of Modern Agriculture(BAIC04–2016)
文摘Background: The effect of amylases combined with exogenous carbohydrase and protease in a newly harvested corn diet on starch digestibility, intestine health and cecal microbiota was investigated in broiler chickens.Methods: Two hunderd and eighty-eight 5-day-old female chickens were randomly divided into six treatments: a newly harvested corn-soybean meal diet(control); control supplemented with 1,500 U/g α-amylase(Enzyme A);Enzyme A + 300 U/g amylopectase + 20,000 U/g glucoamylase(Enzyme B); Enzyme B + protease 10,000 U/g(Enzyme C); Enzyme C + xylanase 15,000 U/g(Enzyme D); and Enzyme D + cellulase 200 U/g + pectinase 1,000 U/g(Enzyme E). Growth performance, starch digestibility, digestive organ morphology, and intestinal microbiota were evaluated in the birds at 16 and 23 d of age.Results: Compared with the control diet, supplementation with Enzyme A significantly decreased ileum lesion scoring at 16 d of age(P < 0.05); supplementation with Enzyme B or Enzyme C showed positive effects on ileal amylopectin and total starch digestibility(P < 0.05); Broilers fed with a diet supplemented with Enzyme D had a tendency to decrease body weight gain at 23 d. Enzyme E supplementation improved lesion scoring of jejunum and ileum at 16 d(P < 0.05), and increased ileal amylopectin or total starch digestibility at 23 d(P < 0.05).Supplementation of enzymes changed cecal microbiota diversity. High numbers of Campylobacter, Helicobacter and Butyricicoccus, Anaerostipes and Bifidobacterium, Sutterella and Odoribacter were the main genera detected in supplementations with Enzymes B, C, D, and E respectively.Conclusions: Supplementation with amylase combined with glucoamylase or protease showed a beneficial effect on starch digestibility and intestinal microbiota diversity, and increased growth of broilers fed with newly harvested corn.
基金supported by the Project of National Key Basic Research and Development, China (Grant No. 2002CB410804)the Natural Science Foundation of Guizhou Province, China (Grant No. 20072058)the Foundation for Young Scholars Scientists of Guizhou University (Grant No. X060036), China.
文摘Two rice varieties, Xiushui 110 with high cadmium (Cd) tolerance and Xiushui 11 with low Cd tolerance were used to study the effects of Cd stress on seed germination, seedling growth and amylase activities. The low cadmium concentration had little effect on seed germination rate. However, cadmium stress could significantly inhibit plumule and radicle growth, especially for radicle growth. Germination index, vigour index, radicle length and amylase activities of Xiushui 11 decreased more significantly with the increasing cadmium level compared with Xiushui 110. The cadmium content in seedlings of Xiushui 11 was higher than that in Xiushui 110 when the cadmium concentration exceeded 5 μmol/L, which caused lower mitotic index in root tips and amylase activities, and more serious cadmium toxicity in Xiushui 11.
基金a part of the project titled ’Future Marine Technology Development’ funded by the Ministry of Oceans and Fisheries, Republic of Korea
文摘Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies.α-Glucosidase and α-amylase are the crucial factors in regulating starch digestion and glucose absorption,making them key targets for many studies to treat postprandial hyperglycemia.We studied the inhibitory activities of microalgal fucoxanthin against rat-intestinalα-glucosidase and pancreaticα-amylase along with the antidiabetic eff ect to induce diff erentiation in 3T3-L1 pre-adipocytes using Oil Red-O staining.Fucoxanthin displayed strong hindrance activities towardα-amylase in a concentration-dependent manner,with an IC50 value of 0.68mmol/L,whereas weak inhibitory activity against α-glucosidase,with an IC 50 value of 4.75 mmol/L.Fucoxanthin also considerably elevated glucose oxidase activity in 3T3-L1 cells by 31.3%at 5μmol/L.During adipocyte differentiation,fucoxanthin showed lipid accumulation in 3T3-L1 cells with no cytotoxicity up to 20μmol/L.However,fucoxanthin had no inhibitory activity on glucose-6-phosphate dehydrogenase.These results suggest that fucoxanthin might be useful for the prevention of obesity or diabetes by inhibiting carbohydrate-hydrolyzing enzymes and lipid accumulation and be utilized as an ingredient for a functional food or dietary supplement.
文摘The marine yeast strain N13d, producing an extracellular amylase, was isolated from the deep sea sediments of the Pa-cific Ocean. This strain was identified to be Aureobasidium pullulans by 18S rRNA gene sequence analysis and routine yeast identi-fication methods. The optimal sea water medium for amylase production by this yeast strain was 1.0% peptone and 1.0% soluble starch with pH 4.0. The optimal conditions for amylase production by this yeast strain were with temperature 28 ℃, aeration rate 6 Lmin-1 and agitation speed 250 rmin-1. Under these conditions, 58.5 units of amylase activity per mg protein were produced within 56 h of fermentation.
文摘BACKGROUND: Measurement of total serum amylase (AMY) is the most widely used biochemical test for the diagnosis of acute pancreatitis, but it is commonly considered a nonspecific marker. To improve the biochemical diagnosis of acute pancreatitis, lipase ( LIP ) and pancreatic amylase (PAMY) have been tested in recent years. The present study was designed to evaluate whether serum LIP and pancreatic PAMY tests could replace total amylase test to improve diagnostic efficiency in the evaluation of acute pancreatitis in patients with hyperamylasemia. METHODS: LIP and PAMY values were determined in serum samples from 92 patients with hyperamylasemia. Reference values for each enzyme were derived from serum samples of 147 healthy subjects. The activities of LIP and PAMY in patients with various diseases were shown directly by the boxplot graph. The diagnostic accuracy of LIP and PAMY was defined as the area under the receiver operating characteristic (ROC) curve. Their sensitivity and specificity in detecting acute pancreatitis at varying cutoff points were shown by the curve, and the best cutoff value for each enzyme was shown by the modified ROC curve. The diagnostic values of LIP, PAMY and LIP + AMY with each upper limit of reference range (ULR) were compared with the corresponding best cutoff values. RESULTS: The references values of LIP and PAMY were 12.2-47.6 U/L and 28-95 U/L, respectively. These values in patients with acute pancreatitis were higher than those patients with other diseases. The areas under the ROC curve ( AUC) of LIP and PAMY were 0. 799 and 0. 792, respectively, With the best diagnostic cutoff point of maximum (sensitivity + specificity) -100%, we obtained values of 97.9 U/L(LIP97.9 =2. 06 × ULR) for LIP and 209 U/L (PAMY209 =2.20 ×ULR) for PAMY. The best cutoff values for LIP, PAMY and LIP +AMY demonstrated the specificity, positive predictive value, and diagnostic efficiency higher than the corresponding ULRs. CONCLUSIONS: Serum LIP and PAMY are specific for the pancreas and might replace total amylase for the diagnosis of acute pancreatitis in hyperamylasemia patients. LIP97.9 is more efficient than PAMY209 in the diagnosis of acute pancreatitis. A combined test of both enzymes is not superior to single test of either enzyme in diagnostic accuracy.
文摘For the last decade, low serum amylase(hypoamylasemia) has been reported in certain common cardiometabolic conditions such as obesity, diabetes(regardless of type), and metabolic syndrome, all of which appear to have a common etiology of insufficient insulin action due to insulin resistance and/or diminished insulin secretion. Some clinical studies have shown that salivary amylase may be preferentially decreased in obese individuals, whereas others have revealed that pancreatic amylase may be preferentially decreased in diabetic subjects with insulin dependence. Despite this accumulated evidence, the clinical relevance of serum, salivary, and pancreatic amylase and the underlying mechanisms have not been fully elucidated. In recent years, copy number variations(CNVs) in the salivary amylase gene(AMY1), which range more broadly than the pancreatic amylase gene(AMY2A and AMY2B), have been shown to be well correlated with salivary and serum amylase levels. In addition, low CNV of AMY1, indicating low salivary amylase, was associated with insulin resistance, obesity, low taste perception/satiety, and postprandial hyperglycemia through impaired insulin secretion at early cephalic phase. In most populations, insulin-dependent diabetes is less prevalent(minor contribution) compared with insulin-independent diabetes, and obesity is highly prevalent compared with low body weight. Therefore, obesity as a condition that elicits cardiometabolic diseases relating to insulin resistance(major contribution) may be a common determinant for low serum amylase in a general population. In this review, the novel interpretation of low serum, salivary, and pancreas amylase is discussed in terms of major contributions of obesity, diabetes, and metabolic syndrome.
文摘AIM To estimate the efficacy of 2 h post-endoscopic retrograde cholangiopancreatography(ERCP) serum amylase levels and other factors for predicting postERCP pancreatitis.METHODS This was a retrospective,single-center cohort study of consecutive patients who underwent ERCP from January 2010 to December 2013.Serum amylase levels were measured 2 h post-procedure,and patient- and procedure-related pancreatitis(PEP) risk factors wereanalyzed using a logistic model.RESULTS A total of 1520 cases(average age 72 ± 12 years,60% male) were initially enrolled in this study,and 1403 cases(725 patients) were ultimately analyzed after the exclusion of 117 cases.Fifty-five of these cases developed PEP.We established a 2 h serum amylase cutoff level of two times the upper limit of normal for predicting PEP.Multivariate analysis revealed that a cannulation time of more than 13 min [odds ratio(OR) 2.28,95%CI:1.132-4.651,P=0.0210] and 2 h amylase levels greater than the cutoff level(OR=24.1,95%CI:11.56-57.13,P<0.0001) were significant predictive factors for PEP.Forty-seven of the 55 patients who developed PEP exhibited 2 h amylase levels greater than the cutoff level(85%),and six of the remaining eight patients who developed PEP(75%) required longer cannulation times.Only 2 of the 1403 patients(0.14%) who developed PEP did not exhibit concerning 2 h amylase levels or require longer cannulation times.CONCLUSION These findings indicate that the combination of 2 h post-ERCP serum amylase levels and cannulation times represents a valuable marker for identifying patients at high risk for PEP.
文摘AIM:To investigate the value of elevated drain amylase concentrations for detecting anastomotic leakage(AL) after minimally invasive Ivor-Lewis esophagectomy(MIILE).METHODS:This was a retrospective analysis of prospectively collected data in two hospitals in the Netherlands. Consecutive patients undergoing MI-ILE were included. A Jackson-Pratt drain next to the dorsal side of the anastomosis and bilateral chest drains were placed at the end of the thoracoscopic procedure. Amylase levels in drain fluid were determined in all patients during at least the first four postoperative days. Contrast computed tomography scans and/or endoscopic imaging were performed in cases of a clinically suspected AL. Anastomotic leakage was defined as any sign of leakage of the esophago-gastric anastomosis on endoscopy,re-operation,radiographic investigations,post mortal examination or when gastro-intestinal contents were found in drain fluid. Receiver operator characteristic curves were used to determine the cut-off values. Sensitivity,specificity,positive predictive value,negative predictive value,risk ratio and overall test accuracy were calculated for elevated drain amylase concentrations.RESULTS:A t o t a l o f 8 9 p a t ie n t s w e re in c lu d e d between March 2013 and August 2014. No differences in group characteristics were observed between patients with and without AL,except for age. Patients with AL were older than were patients without AL(P = 0.01). One patient(1.1%) without AL died within 30 d after surgery due to pneumonia and acute respiratory distress syndrome. Anastomotic leakage that required any intervention occurred in 15 patients(16.9%). Patients with proven anastomotic leakage had higher drain amylase levels than patients without anastomotic leakage [median 384 IU/L(IQR 34-6263) vs median 37 IU/L(IQR 26-66),P = 0.003]. Optimal cut-off values on postoperative days 1,2,and 3 were 350 IU/L,200 IU/L and 160 IU/L,respectively. An elevated amylase level was found in 9 of the 15 patients with AL. Five of these 9 patients had early elevations of their amylase levels,with a median of 2 d(IQR 2-5) before signs and symptoms occurred.CONCLUSION:Measurement of drain amylase levels is an inexpensive and easy tool that may be used to screen for anastomotic leakage soon after MI-ILE. However,clinical validation of this marker is necessary.
基金We are grateful to the nonprofit organization Epidemiological and Clinical Research Information Network(ECRIN)for providing their valuable support with this work.
文摘Many studies investigating postoperative pancreatic fistula(POPF)after gastrectomy,including studies measuring drain amylase content(D-AMY)as a predictive factor have been reported.This article reviews previous studies and looks to the future of measuring D-AMY in patients after gastrectomy.The causes of pancreatic fluid leakage are;the parenchymal and/or thermal injury to the pancreas,and blunt injury to the pancreas by compression and retraction.Measurement of D-AMY to predict POPF has become common in clinical practice after pancreatic surgery and was later extended to the gastric surgery.Several studies have reported associations between D-AMY and POPF after gastrectomy,and the high value of D-AMY on postoperative day(POD)1 was an independent risk factor.To improve both sensitivity and specificity,attempts have been made to enhance the predictive accuracy of factors on POD 1 as well as on POD 3 as combined markers.Although several studies have shown a high predictive ability of POPF,it has not necessarily been exploited in clinical practice.Many problems remain unresolved;ideal timing for measurement,optimal cut-off value,and means of intervention after prediction.Prospective clinical trial could be imperative in order to develop D-AMY measurement in common clinical practice for gastric surgery.
基金Supported by Shanghai Shenkang Hospital Development Center,No.SHDC12016109.
文摘BACKGROUND Hypothyroidism is an endocrine disorder that has worldwide prevalence and can affect multiple organ systems.We report a case of hypothyroidism with elevated pancreatic amylase and trypsin without acute pancreatitis.No such case has been previously reported.CASE SUMMARY A 29-year-old woman did not pay much attention to a fever 4 d prior.During this time,she experienced anorexia and only drank a small amount of water every day.She did not present with abdominal distension,postprandial nausea,vomiting,cough or expectoration.After physical and laboratory examinations,the patient was diagnosed with hypothyroidism.During the course of the disease,hypothyroidism was generally accompanied by constantly increased pancreatic amylase and trypsin.After admission,the possible etiology of the patient was excluded and the concentrations of pancreatic lipase and amylase in serum were>2000U/L(reference range 23-300 U/L)and 410 U/L(reference range 30-110 U/L),respectively.So we highly suspected that it may be acute pancreatitis.Interestingly,she never developed any complications associated with acute pancreatitis despite high levels of serum pancreatic amylase and trypsin,and she reported no symptoms of abdominal pain.Serum amylase and lipase decreased gradually after active thyroxine supplementation,and the patient was discharged from the hospital after active treatment.CONCLUSION This case suggests that clinicians should pay attention to hypothyroidism with elevated pancreatic amylase and trypsin,even if no complications of acute pancreatitis are reported.
文摘Based on the different hydrophobicities of the intermediates of proteins the various conformational intermediates of the refolding of a-amylase originally denatured with 8.0 mol/L urea solution were separated with high performance hydrophobic interaction chromatography(HPHIC). Compared to the separation of the same intermediates with weak anion exchange chromatography and size-exclusion chromatography the result obtained with HPHIC is the best It would be expected that HPHIC may be a strongly potential tool to separate intermediates of some proteins which cannot be, or cannot completely be refolded by HPHIC.
基金Supported by Young Doctor Fund of Gansu Education Department,China(2021QB-034)。
文摘In order to obtain pure enzyme with high activity,two amylase producing strains were isolated from soil samples,and named as the strains LZ-10 and LZ-11.According to morphologic observation,physiology and biochemistry experiments,16S rRNA and gyrB gene analysis,the strains LZ-10 and LZ-11 were identified as Bacillus subtilis.Adopted the method of ammonium sulfate,DEAE-52 anion purify enzyme,finally used polyacrylamide gel electrophoresis(SDS-PAGE)to detect molecular weight.The strain LZ-10 had an amylase activity of 123.3 U·mL^(-1),a purification factor of 6.8,a recovery rate of 69.5% and an optimal temperature of 50℃.The amylase activity of the strain LZ-11 was 59.91 U·mL^(-1),the purification factor was 4.5,the recovery rate was 60.5%,and the optimum temperature was 55℃.The commodity enzyme derived from Bacillus subtilis was 37.5 U·mL^(-1).The relative molecular weight of amylase activity from the two strains was 55 ku.Both thermal stability and pH stability were higher than those of commercialized amylase.
文摘Two sampling devices that allow saliva collection through absorption to a cotton roll (Salivette?-method) or to small cotton pellets (VectaSpinTM Micro [VSM]-method) were studied. Any loss of salivary alpha-amylase (sAA) activity in relation to the saliva volume absorbed and harvested by centrifugation was examined. A pooled saliva sample prepared from stimulated whole saliva (collected by drooling) of 30 subjects was used. Three different saliva volumes (2.9 ml, 1.5 ml, and 0.8 ml) were tested on cotton rolls and two (0.03 ml, and 0.015 ml) on cotton pellets. The sample sAA activity was determined from the hydrolysis of 2-chloro-4-nitrophenyl-α-D-maltotrioside. In comparison with the original drooling sample, no sAA loss was observed in 1.5 ml samples tested with Salivette, while a significant decrease of activity was recorded with smaller volumes. VSM collected samples showed a non-volume dependent decrease of sAA activity of about 25%. Salivette requires large saliva volumes to allow an accurate sAA estimation. With cases of limited saliva access, VSM may be a suitable sampling device.
文摘<strong>Background:</strong> Geophagy is the consumption of earth materials which occurs across several cultures. For several reasons, pregnant women in many parts of West Africa including Nigeria frequently consume kaolin. This study was carried out to determine the influence of kaolin consumption on serum electrolytes, glucose and amylase levels of pregnant women attending antenatal clinic in a Teaching Hospital in the south east Nigeria. <strong>Methods: </strong>A total of eighty pregnant women recruited for this study were grouped as follows;Group 1, (30 geophagic pregnant women in the first trimester), Group 2 (30 geophagic pregnant women in the second trimester) and Group 3 (20 non-geophagic pregnant women that served as control). Subjects in Groups 1 and 2 were subdivided into three based on the quantity of kaolin consumed per week: group A (100 g/week), group B (150 g/week) and group C (200 g/week). Preliminary analysis of the calcium content of kaolin was carried out. Serum levels of potassium, sodium, chloride, bicarbonate, glucose and amylase of the subjects were determined. <strong>Results:</strong> Calcium level in kaolin was below the recommended daily intake in food. The concentrations of potassium in geophagic pregnant women who consumed 150 g and 200 g of kaolin per week were significantly (p < 0.05) lower in both 1<sup>st</sup> and 2<sup>nd</sup> trimester groups., There was a significant (p < 0.05) decrease in sodium concentration (132.2 ± 2.0) of the 2<sup>nd</sup> trimester pregnant women that consumed 200 g of kaolin per week. The concentrations of chloride and bicarbonate were not significantly (p > 0.05) affected in all the groups. Serum amylase concentration decreased significantly (p < 0.05) in the 1<sup>st</sup> and 2<sup>nd</sup> trimester pregnant women on 150 g and 200 g of kaolin per week, while the plasma glucose concentration was significantly (p < 0.05) elevated in the same groups. <strong>Conclusion:</strong> This study concludes that kaolin consumption in pregnant women may predispose to gestational diabetes, electrolytes imbalance and reduced intestinal enzymes activities.
文摘Municipal waste is one of the most hazardous components of developing countries. However, enzymes do provide an eco-friendly solution in this case. Amylase is an important enzyme in food, textile and pharmaceutical industry and can be used for bioconversion of waste. From the municipal solid waste we have isolated an amylase producing bacteria that can grow in the irritant municipal waste and help in their bio conversation. The bacteria were identified as Cronobacter sakazakii Jor52 (C2). The optimized media for maximum amylase production after 24 h of incubation, contains 2% starch, 0.6% peptone, 0.01% CaCl2, 0.05% KCl, 0.05% MgSO4 and 0.05% K2HPO4. The crude enzyme activity and stability study revealed that the amylase is stable within the pH 6 - 8 and temperature 30°C - 40°C and give maximum activity at 37°C at pH-8.
文摘Cassava peels are generated as waste on soils during cassava processing in many tropical countries. This work set out to isolate some microorganisms associated with cassava peel degradation and characterize amylase enzymes responsible for the degradation under some physiological conditions. A total of 30 bacteria was isolated from the peels with Bacillus species occurring the most (46.5%) and Enterobacter species (13.3%) being the next. Frequencies of fungal isolations was Rhizopus sp. (35%);Aspergillus niger (25%);Aspegillus flavus (20%) and Penicillium species (20%). Bacillus cereus, Bacillus substilis Bacillus pumillus, Aspergillus niger and Apergillus flavus were selected and screened for their abilities to produce amylase. Amylase activity was highest at day 4 for B. substilis (39.4 units/ml) and A. flavus (66.1 units/ml);at day 3 for B. cereus (55.6 units/ml) and A. niger (44.6 units/ ml). While maximum amylase activity was obtained at day 6 for B. pumilus (80.2 units/ml). Optimum pH for amylases from the two fungal isolate was 6.0 (A. niger = 53.5 units/ml and A. flavus = 65.4 units/ml). While optimum pH for B.cereus (51.7 units/ ml) and B. pumilus (44.6 units/ml) was 6.5 and for B. substilis (56.1 units/ml) at pH 7.0. Amylase activities increased from 20°C to 40°C for amylase from Bacillus sp. and 20°C to 50°C for amylase from the Aspergillus sp. after which there was a decline in activities as temperature increased to 80°C. Effect of heating duration (at 70°C for 5 minutes) on the amylase showed that A. niger has the highest activity of 127 units/ml. Effect of substrate concentration on amylase activity showed that amylase form A. flavus had the highest activity of 72.2 units/ml at 0.4% substrate concentration. The implications of the findings were discussed.
文摘Three human α-amylases exist: Amy1 (salivary amylase), Amy2A (pancreatic amylase), and Amy2B (expressed in various tissues). These amylases share a 97% - 99% amino acid sequence identity, and two potential N-glycosylation sites (N427 and N476) are commonly found in the C-terminal region. In general, salivary amylase is more frequently glycosylated than pancreatic amylase, and it is still uncertain why differences in the glycosylation pattern among human amylase iso-zymes occur. In this study, we found that there was no significant change of ratio of glycosylated molecules among isozymes produced by the same cultured cells, indicating that glycosylation of amylase is influenced by the type of cell producing the enzyme rather than being an inherent property of the amylase isozymes. We analyzed the glycosylation efficiency of N-glycosylation sites in recombinant Amy2A mutants produced by HEK293 cells and found that glycosylation efficiencies of N427 and N476 were 3% - 18% and 40% - 52%, respectively, indicating that the major N-glycosylation site of glycosylated Amy2A produced by HEK293 cells is N476. The difference in the glycosylation efficiency of each N-glycosylation site also seemed to contribute in part to generate different glycosylation patterns of human amylases. We also confirmed that the C-terminal region of human amylase plays a critical role in secretion, although glycosylation does not play a part in this effect.
文摘Owing to the production of alpha, beta and gamma amylase subtypes;starch degrading microbes, especially bacteria have an invincible role in the food, fermentation, textile and paper industries. Of them, α-amylases from Bacillus spp. have contributed tremendous advancements in bio-industry, especially in starch, detergent and pharmaceutical arena. Though general reviews are seen in literature on amylases, no focused review is available yet solely on α-amylases produced by Bacillus spp. Hence, this focused review on α-amylases from the genus Bacillus is designed in such a way that it should give a vivid picture on most of the aspects on bacillial α-amylases in a handy module with an industrial perspective. With a short introduction on amylases in general, α-amylases from various species of Bacillus reviewed herein encompasses production of α-amylases by submerged and solid-state fermentations;nutrients and other factors required for maximizing production;immobilization strategies for whole cells or purified enzyme;an overview on the molecular weight of the enzyme;followed by distinct sections for purification, characterisation, stability and crystal structure;and concluded with a section on industrial applications of the α-amylases from Bacillus spp.
文摘An evaluation method was designed for reference in the experiment,which was further verified by investigating the changes of various factors,including additive amount of enzyme,washing temperature,soaking time,pH value and amylase source,etc.Based on tests and comparison,it is confirmed that this method can effectively and quantitatively evaluate the performance of amylase in detergents for hand dishwashing.
