There are evidences indicating that cysteine proteases play an essential role in malaria parasites;therefore, an obvious area of investigation is the inhibition of these enzymes to treat malaria. Small cysteine protea...There are evidences indicating that cysteine proteases play an essential role in malaria parasites;therefore, an obvious area of investigation is the inhibition of these enzymes to treat malaria. Small cysteine protease inhibitors of malaria are well studied, but macromolecular nature of inhibitor is a new field to explore. In malarial cysteine proteases, there are macromolecular endogenous inhibitors playing important roles in regulation of the cysteine protease activity of parasite and host. Recent studies suggested that there are known and characterized endogenous inhibitors like falstatin present in P. falciparum, PbICP (inhibitor of cysteine protease in P. berghei), PyICP (inhibitor of cysteine protease in P. yoelli), and other macromolecular inhibitors which are the prodomain of enzyme itself regulating the activity of the mature enzyme. All the known macromolecular endogenous inhibitors are using specific loop-like structure to interact with malarial cysteine proteases. The majority of macromolecular inhibitors are competitive in nature, and block access to the active site of their target protease, but do not bind in a strictly substrate-like manner. They rather interact with the protease subsites and catalytic residues in a non-catalytically competent manner. In future, designing inhibitors based on these protein-protein interactions will be a new approach in the field of malaria. Since macromolecular inhibitors can gain potency through the burial of a large surface area and specificity through contacts with secondary binding sites critical for inhibition, and could be less prone to drug resistant mutation.展开更多
[Objective] This study aimed to clone and analyze the cysteine proteinase inhibitor gene from seedless litchi. [Method] According to the EST sequence of cysteine proteinase inhibitor in constructed SSH subtractive lib...[Objective] This study aimed to clone and analyze the cysteine proteinase inhibitor gene from seedless litchi. [Method] According to the EST sequence of cysteine proteinase inhibitor in constructed SSH subtractive library of seedless litchi abortion, nucleotide sequence of the cysteine proteinase inhibitor gene was obtained by using RACE technology and analyzed by using bioinformatics software. [Result] A cysteine protease inhibitor gene was obtained with the sequence of 635 bp containing a 321 bp open reading frame. It was predicted that the encoded protein contained 106 amino acids with conserved domain of cysteine proteinase inhibitor and had relatively high homology with the cysteine proteinase inhibitor gene of several species. [Conclusion] This study laid the foundation for further exploring the physiological functions of this cysteine proteinase inhibitor gene in plants.展开更多
A series of N1-substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyrazolethiocarboxamide were prepared from the Mannich bases of aryl ketones in good yields. Some derivatives were found to be active against the cysteine pr...A series of N1-substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyrazolethiocarboxamide were prepared from the Mannich bases of aryl ketones in good yields. Some derivatives were found to be active against the cysteine protease of T.cruzi..展开更多
AIM: Cysteine peptidase (CP) and its inhibitor (CPI) are a matrix protease that may be associated with colorectal carcinoma invasion and progression, and vitamin E is also a stimulator of the immunological system. Our...AIM: Cysteine peptidase (CP) and its inhibitor (CPI) are a matrix protease that may be associated with colorectal carcinoma invasion and progression, and vitamin E is also a stimulator of the immunological system. Our purpose was to determine the correlation between the expression of cysteine peptidases and their endogenous inhibitors,and the level of vitamin E in sera of patients with colorectal cancer in comparison with healthy individuals.METHODS: The levels of cysteine peptidases and their inhibitors were determined in the sera of patients with primary and metastatic colorectal carcinoma and healthy individuals using fluorogenic substrate, and the level of vitamin E was determined by HPLC.RESULTS: The levels of cysteine peptidases and their inhibitors were significantly higher in the metastatic colorectal cancer patients than that in the healthy controls (P＜0.05).The activity of CP increased 2.2-fold, CPI 2.8-fold and vitamin E decreased 3.4-fold in sera of patients with metastasis in comparison with controls. The level of vitamin E in healthy individuals was higher, whereas the activity of cysteine peptidases and their inhibitors associated with complexes was lower than that in patients with cancer of the digestive tract.CONCLUSION: These results suggest that the serum levels of CP and their inhibitors could be an indicator of the prognosis for patients with metastatic colorectal cancer. Vitamin E can be administered prophylactically to prevent digestive tract neoplasmas.展开更多
AIM: To examine the effectiveness of human placental inhibitors, by injecting vitamin E to rats with transplanted Norris-5123 hepatoma, on the expression of cathepsins B and L in tumor, liver, lung and blood sera afte...AIM: To examine the effectiveness of human placental inhibitors, by injecting vitamin E to rats with transplanted Norris-5123 hepatoma, on the expression of cathepsins B and L in tumor, liver, lung and blood sera after transplantation of Norris 5123 hepatoma.METHODS: Animals were divided into 10 groups receiving three different concentrations of vitamin E and inhibitors along or in combination and compared with negative control (healthy rats) and positive control (tumor rats). Effectiveness of treatment was evaluated with regard to survival time,tumor response and determination of the activities of proteolytic enzymes and their inhibitors using flurogenic substrates.RESULTS: Cathepsins B and L activities were elevated by 16-fold in comparison with negative control tissues, and their endogenous inhibitor activity decreased by 1.2-fold before treatment. In several cases, tumors completely disappeared following vitamin E plus human placental cyteine protease inhibitor (CPI) compared with controls.The number of complete tumor responses was higher when 20 m/kg vitamin E plus 400 μg of CPI was used, i.e.7/10 rats survived more than two mo. Cathepsins B and L were expressed significantly in tumor, liver, lung tissues and sera in parallel to the increasing of the endogenous inhibitor activity compared with the controls after treatment (P＜0.0001).CONCLUSION: The data indicate formation of metastasis significantly reduced in treated rats, which might provide a therapeutic basis for anti-cancer therapy.展开更多
Breeding for wilt resistance and its theoretical basis are primarily responsible for increases in cotton yield and fiber quality. Breeding for immunity is the most efficient method in our struggle with infectious dise...Breeding for wilt resistance and its theoretical basis are primarily responsible for increases in cotton yield and fiber quality. Breeding for immunity is the most efficient method in our struggle with infectious diseases.展开更多
A cDNA library was constructed with 1.5×10~6 pfu from rice immature seeds,fromwhich a cDNA clone for rice thiol proteinase inhibitor,oryzacystatin(OC),was isolated byscreening with synthesized oligodeoxynucleotid...A cDNA library was constructed with 1.5×10~6 pfu from rice immature seeds,fromwhich a cDNA clone for rice thiol proteinase inhibitor,oryzacystatin(OC),was isolated byscreening with synthesized oligodeoxynucleotide probe,which contained a 309bp open read-ing frame,84bp 5′-end noncoding region and a poly(A)signal AATAAA at the 3′-end fol-lowed by 31Nt poly(A).Then the coding region of OC was amplified and inserted into thedownstream of λP_RP_L promoter for thermal-inducible expression in E.coli.Shifting the cul-ture temperature from 30℃ to 42℃ led to a high level expression of OC,which exhibited adistinct band of 12.0 kDa and accounted for at least 10% of the total soluble proteins fromSDS-PAGE.The papain-inhibitory activity of the expressed OC was further confirmed.展开更多
The study was aimed at the evaluation of the effects of breed, age, different digestion stimulators, and dietary crude protein (CP) level on the activities of proteolytic enzymes in pancreatic tissue and duodenal chym...The study was aimed at the evaluation of the effects of breed, age, different digestion stimulators, and dietary crude protein (CP) level on the activities of proteolytic enzymes in pancreatic tissue and duodenal chymus (in vivo), serum trypsin and α1-proteinase inhibitor (A1PI) concentrations in meat-type chicks. The study of age dynamics of trypsin and A1PI concentrations was performed on the chicks of hybrid cross “Smena-8”and two parental lines (Plymouth Rock and Cornish) fed standard commercial corn-wheat-SBM diets. Twenty birds per breed were euthanized at 1, 7, 14, 21, 28 and 35 days of age to obtain blood samples and pancreatic homogenate. Experiments on the effects of different digestion promotors (probiotic, acidifier, phytobiotic, enzymatic preparation) and different CP levels (finisher diet, CP 20%, vs. ground corn, CP 8.5%) were performed on 12 hybrid chicks with fistulated duodenum from 14 to 50 days of age. The following conclusions were made: 1) At 1 day of age high proteolytic activity in pancreatic tissue and maximal serum concentrations of trypsin and A1PI were found in both hybrid and parental lines. Since 7 to 35 days of age A1PI concentration was nearly constant, serum trypsin concentration decreased while proteolytic activity in pancreatic tissue exhibited undulate increase;2) Proteolytic activity in pancreatic tissue was higher in hybrids compared to the parental lines from 7 to 35 days of age (p 0.05);3) Supplementation of diet with exogenous enzymes stimulated the digestion due to the increase in protease activity in duodenal chymus by 9.1% compared to unsupplemented control (p 0.05);4) Proteolytic activity in duodenal chymus significantly responded to the substitution of ground corn for the complete diet by 2-fold decrease while serum trypsin concentration responded by 2.5-fold increase (p 0.001). This fact can indicate that physiological functions of digestive proteases are not confined to the digestive processes.展开更多
Objective: To study the effects of quercetin (QU) on matrix metallo-proteinases (MMPs), the tissue inhibitor of matalloproteinase-1 (TIMP-1), procollagen I and 2 proteoglycans (decorin and biglycan) mRNA expression in...Objective: To study the effects of quercetin (QU) on matrix metallo-proteinases (MMPs), the tissue inhibitor of matalloproteinase-1 (TIMP-1), procollagen I and 2 proteoglycans (decorin and biglycan) mRNA expression in cultured rat hepatic stellate cell line HSC-T6 cells.Methods: Cells were treated with different concentrations of QU (12.5, 25, 50 μmol/L) or drug solvent (0.1 % Me2SO) for 24 h.mRNA expression was determined by reverse transcription polymerase chain reaction (RT-PCR).Results: QU (12.5 - 50 μmol/L) enhanced collagenase (rat MMP-13) and membrane type1-MMP (MMP-14) mRNA expression, decreased procollagen I mRNA expression in a concentration-dependent manner, but did not affect gelatinase-A (MMP-2), TIMP-1, decorin and biglycan expression.Conclusion: QU may decrease matrix deposition and increase matrix degradation, which might be beneficial to liver fibrosis.展开更多
文摘There are evidences indicating that cysteine proteases play an essential role in malaria parasites;therefore, an obvious area of investigation is the inhibition of these enzymes to treat malaria. Small cysteine protease inhibitors of malaria are well studied, but macromolecular nature of inhibitor is a new field to explore. In malarial cysteine proteases, there are macromolecular endogenous inhibitors playing important roles in regulation of the cysteine protease activity of parasite and host. Recent studies suggested that there are known and characterized endogenous inhibitors like falstatin present in P. falciparum, PbICP (inhibitor of cysteine protease in P. berghei), PyICP (inhibitor of cysteine protease in P. yoelli), and other macromolecular inhibitors which are the prodomain of enzyme itself regulating the activity of the mature enzyme. All the known macromolecular endogenous inhibitors are using specific loop-like structure to interact with malarial cysteine proteases. The majority of macromolecular inhibitors are competitive in nature, and block access to the active site of their target protease, but do not bind in a strictly substrate-like manner. They rather interact with the protease subsites and catalytic residues in a non-catalytically competent manner. In future, designing inhibitors based on these protein-protein interactions will be a new approach in the field of malaria. Since macromolecular inhibitors can gain potency through the burial of a large surface area and specificity through contacts with secondary binding sites critical for inhibition, and could be less prone to drug resistant mutation.
文摘[Objective] This study aimed to clone and analyze the cysteine proteinase inhibitor gene from seedless litchi. [Method] According to the EST sequence of cysteine proteinase inhibitor in constructed SSH subtractive library of seedless litchi abortion, nucleotide sequence of the cysteine proteinase inhibitor gene was obtained by using RACE technology and analyzed by using bioinformatics software. [Result] A cysteine protease inhibitor gene was obtained with the sequence of 635 bp containing a 321 bp open reading frame. It was predicted that the encoded protein contained 106 amino acids with conserved domain of cysteine proteinase inhibitor and had relatively high homology with the cysteine proteinase inhibitor gene of several species. [Conclusion] This study laid the foundation for further exploring the physiological functions of this cysteine proteinase inhibitor gene in plants.
文摘A series of N1-substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyrazolethiocarboxamide were prepared from the Mannich bases of aryl ketones in good yields. Some derivatives were found to be active against the cysteine protease of T.cruzi..
文摘AIM: Cysteine peptidase (CP) and its inhibitor (CPI) are a matrix protease that may be associated with colorectal carcinoma invasion and progression, and vitamin E is also a stimulator of the immunological system. Our purpose was to determine the correlation between the expression of cysteine peptidases and their endogenous inhibitors,and the level of vitamin E in sera of patients with colorectal cancer in comparison with healthy individuals.METHODS: The levels of cysteine peptidases and their inhibitors were determined in the sera of patients with primary and metastatic colorectal carcinoma and healthy individuals using fluorogenic substrate, and the level of vitamin E was determined by HPLC.RESULTS: The levels of cysteine peptidases and their inhibitors were significantly higher in the metastatic colorectal cancer patients than that in the healthy controls (P＜0.05).The activity of CP increased 2.2-fold, CPI 2.8-fold and vitamin E decreased 3.4-fold in sera of patients with metastasis in comparison with controls. The level of vitamin E in healthy individuals was higher, whereas the activity of cysteine peptidases and their inhibitors associated with complexes was lower than that in patients with cancer of the digestive tract.CONCLUSION: These results suggest that the serum levels of CP and their inhibitors could be an indicator of the prognosis for patients with metastatic colorectal cancer. Vitamin E can be administered prophylactically to prevent digestive tract neoplasmas.
文摘AIM: To examine the effectiveness of human placental inhibitors, by injecting vitamin E to rats with transplanted Norris-5123 hepatoma, on the expression of cathepsins B and L in tumor, liver, lung and blood sera after transplantation of Norris 5123 hepatoma.METHODS: Animals were divided into 10 groups receiving three different concentrations of vitamin E and inhibitors along or in combination and compared with negative control (healthy rats) and positive control (tumor rats). Effectiveness of treatment was evaluated with regard to survival time,tumor response and determination of the activities of proteolytic enzymes and their inhibitors using flurogenic substrates.RESULTS: Cathepsins B and L activities were elevated by 16-fold in comparison with negative control tissues, and their endogenous inhibitor activity decreased by 1.2-fold before treatment. In several cases, tumors completely disappeared following vitamin E plus human placental cyteine protease inhibitor (CPI) compared with controls.The number of complete tumor responses was higher when 20 m/kg vitamin E plus 400 μg of CPI was used, i.e.7/10 rats survived more than two mo. Cathepsins B and L were expressed significantly in tumor, liver, lung tissues and sera in parallel to the increasing of the endogenous inhibitor activity compared with the controls after treatment (P＜0.0001).CONCLUSION: The data indicate formation of metastasis significantly reduced in treated rats, which might provide a therapeutic basis for anti-cancer therapy.
文摘Breeding for wilt resistance and its theoretical basis are primarily responsible for increases in cotton yield and fiber quality. Breeding for immunity is the most efficient method in our struggle with infectious diseases.
基金Supported by Prime Minister FouNdationthe High Techriology Research and Development Programme of ChinaRockefeller Foun-dation.
文摘A cDNA library was constructed with 1.5×10~6 pfu from rice immature seeds,fromwhich a cDNA clone for rice thiol proteinase inhibitor,oryzacystatin(OC),was isolated byscreening with synthesized oligodeoxynucleotide probe,which contained a 309bp open read-ing frame,84bp 5′-end noncoding region and a poly(A)signal AATAAA at the 3′-end fol-lowed by 31Nt poly(A).Then the coding region of OC was amplified and inserted into thedownstream of λP_RP_L promoter for thermal-inducible expression in E.coli.Shifting the cul-ture temperature from 30℃ to 42℃ led to a high level expression of OC,which exhibited adistinct band of 12.0 kDa and accounted for at least 10% of the total soluble proteins fromSDS-PAGE.The papain-inhibitory activity of the expressed OC was further confirmed.
文摘The study was aimed at the evaluation of the effects of breed, age, different digestion stimulators, and dietary crude protein (CP) level on the activities of proteolytic enzymes in pancreatic tissue and duodenal chymus (in vivo), serum trypsin and α1-proteinase inhibitor (A1PI) concentrations in meat-type chicks. The study of age dynamics of trypsin and A1PI concentrations was performed on the chicks of hybrid cross “Smena-8”and two parental lines (Plymouth Rock and Cornish) fed standard commercial corn-wheat-SBM diets. Twenty birds per breed were euthanized at 1, 7, 14, 21, 28 and 35 days of age to obtain blood samples and pancreatic homogenate. Experiments on the effects of different digestion promotors (probiotic, acidifier, phytobiotic, enzymatic preparation) and different CP levels (finisher diet, CP 20%, vs. ground corn, CP 8.5%) were performed on 12 hybrid chicks with fistulated duodenum from 14 to 50 days of age. The following conclusions were made: 1) At 1 day of age high proteolytic activity in pancreatic tissue and maximal serum concentrations of trypsin and A1PI were found in both hybrid and parental lines. Since 7 to 35 days of age A1PI concentration was nearly constant, serum trypsin concentration decreased while proteolytic activity in pancreatic tissue exhibited undulate increase;2) Proteolytic activity in pancreatic tissue was higher in hybrids compared to the parental lines from 7 to 35 days of age (p 0.05);3) Supplementation of diet with exogenous enzymes stimulated the digestion due to the increase in protease activity in duodenal chymus by 9.1% compared to unsupplemented control (p 0.05);4) Proteolytic activity in duodenal chymus significantly responded to the substitution of ground corn for the complete diet by 2-fold decrease while serum trypsin concentration responded by 2.5-fold increase (p 0.001). This fact can indicate that physiological functions of digestive proteases are not confined to the digestive processes.
文摘Objective: To study the effects of quercetin (QU) on matrix metallo-proteinases (MMPs), the tissue inhibitor of matalloproteinase-1 (TIMP-1), procollagen I and 2 proteoglycans (decorin and biglycan) mRNA expression in cultured rat hepatic stellate cell line HSC-T6 cells.Methods: Cells were treated with different concentrations of QU (12.5, 25, 50 μmol/L) or drug solvent (0.1 % Me2SO) for 24 h.mRNA expression was determined by reverse transcription polymerase chain reaction (RT-PCR).Results: QU (12.5 - 50 μmol/L) enhanced collagenase (rat MMP-13) and membrane type1-MMP (MMP-14) mRNA expression, decreased procollagen I mRNA expression in a concentration-dependent manner, but did not affect gelatinase-A (MMP-2), TIMP-1, decorin and biglycan expression.Conclusion: QU may decrease matrix deposition and increase matrix degradation, which might be beneficial to liver fibrosis.
