Endomorphin-1 is an endogenous opioid peptide that mediates pain relief through interaction with the μ-opioid receptor in the central nervous system. To enhance the metabolic stability of this tetrapeptide, cyclisati...Endomorphin-1 is an endogenous opioid peptide that mediates pain relief through interaction with the μ-opioid receptor in the central nervous system. To enhance the metabolic stability of this tetrapeptide, cyclisation through the formation of a disulfide bridge between the side chains of cysteine residues added to the sequence was explored. A further increase in stability was achieved through N-terminal modification with lipoamino acid and lactose succinamic acid, and the inclusion of D-amino acids. The latter also provided an alternative spatial arrangement of the aromatic side chains. The lipidated cyclic derivatives were insoluble in aqueous buffer, however, the cyclic peptides and glycopeptides showed greatly improved stability towards enzymatic degradation in human plasma.展开更多
Endomorphin 1(EM 1) and its six analogs which were designed by rationally replacing the 2 /3 amino acid(Aa) of EM 1 were synthesized by using liquid phase peptides synthesis method to study their action of opiate rece...Endomorphin 1(EM 1) and its six analogs which were designed by rationally replacing the 2 /3 amino acid(Aa) of EM 1 were synthesized by using liquid phase peptides synthesis method to study their action of opiate receptor binding(AORB). The order of their affinity intensity for μ opiate receptor(MOR) was EM 1 >[ D Ala 2]EM 1 >[ D Pro 2]EM 1 > EM 1 >[ L Tyr 3]EM >[ L Pro 3]EM >EM The sequence of their selectivity for MOR is EM 1 >[ D Pro 2]EM 1 =[ L Tyr 3]EM >[ D Ala 2]EM 1 =[ L Pro 3]EM >EM The results showed that, comparatively speaking, the 2 Aa was more closely related to the selectivity of EM 1 while the 3 Aa to their affinity, though the different replacement changed the AORB of EM 1 dissimilarly.展开更多
目的探讨内吗啡肽-1对心肌缺血再灌注损伤中PI3K/Akt信号通路的作用以及对细胞凋亡的影响。方法将50只SD雄性大鼠随机分为5组:假手术组(S组)、缺血再灌注组(IR组)、内吗啡肽-1后处理组(EM50组)、内吗啡肽-1+渥曼青霉素后处理组(EM50+Wor...目的探讨内吗啡肽-1对心肌缺血再灌注损伤中PI3K/Akt信号通路的作用以及对细胞凋亡的影响。方法将50只SD雄性大鼠随机分为5组:假手术组(S组)、缺血再灌注组(IR组)、内吗啡肽-1后处理组(EM50组)、内吗啡肽-1+渥曼青霉素后处理组(EM50+Wort组)和PI3K/Akt信号通路抑制剂渥曼青霉素后处理组(Wort组)。采用结扎大鼠心脏左冠状动脉前降支30 min,再灌注120 min复制心肌缺血再灌注模型,实验期间动态监测大鼠心率、平均动脉压;再灌注结束后检测大鼠血浆乳酸脱氢酶、肌酸激酶、肌钙蛋白I、白介素-6、肿瘤坏死因子-α、氧化应激指标超氧化物歧化酶和丙二醛等生化指标,RT-PCR检测Bax和Bcl-2基因的表达情况,Western blot检测心肌组织中凋亡相关蛋白cleaved caspase-3、磷酸化Akt蛋白和总Akt蛋白的表达。结果与S组比较,IR组心率和血压降低(P<0.05);与IR组比较,EM50组心率和血压有所增高(339.94±26.65 vs 284.01±34.99;75.02±14.45 vs 55.83±20.98,P<0.05);血浆中乳酸脱氢酶、肌酸激酶、肌钙蛋白I、白介素-6、肿瘤坏死因子-α和丙二醛含量或活性下降(P<0.05),氧化应激指标超氧化物歧化酶活性增加(132.77±8.25 vs 84.10±12.42,P<0.05);p-Akt蛋白表达水平较高(0.61±0.06 vs 0.38±0.04,P<0.05),Bax基因和cleaved caspase-3蛋白表达量降低(1.70±0.39 vs 3.78±0.71;0.30±0.08 vs 0.53±0.07,P<0.05),Bcl-2基因的表达量升高(1.20±0.44 vs 0.55±0.25,P<0.05);与EM50组比较,EM50+Wort组心率和血压降低(P<0.05);血浆中乳酸脱氢酶、肌酸激酶、肌钙蛋白I、白介素-6、肿瘤坏死因子-α和丙二醛含量或活性增加(P<0.05),氧化应激指标超氧化物歧化酶活性降低(P<0.05);p-Akt蛋白表达水平较低(P<0.05),Bax基因和cleaved caspase-3蛋白表达量升高(P<0.05),Bcl-2基因表达量降低(P<0.05)。结论 EM-1后处理可调节细胞凋亡,减轻心肌缺血再灌注损伤。PI3K/Akt信号通路可能对EM-1后处理产生的心肌保护效应发挥一定的介导作用。展开更多
文摘Endomorphin-1 is an endogenous opioid peptide that mediates pain relief through interaction with the μ-opioid receptor in the central nervous system. To enhance the metabolic stability of this tetrapeptide, cyclisation through the formation of a disulfide bridge between the side chains of cysteine residues added to the sequence was explored. A further increase in stability was achieved through N-terminal modification with lipoamino acid and lactose succinamic acid, and the inclusion of D-amino acids. The latter also provided an alternative spatial arrangement of the aromatic side chains. The lipidated cyclic derivatives were insoluble in aqueous buffer, however, the cyclic peptides and glycopeptides showed greatly improved stability towards enzymatic degradation in human plasma.
文摘Endomorphin 1(EM 1) and its six analogs which were designed by rationally replacing the 2 /3 amino acid(Aa) of EM 1 were synthesized by using liquid phase peptides synthesis method to study their action of opiate receptor binding(AORB). The order of their affinity intensity for μ opiate receptor(MOR) was EM 1 >[ D Ala 2]EM 1 >[ D Pro 2]EM 1 > EM 1 >[ L Tyr 3]EM >[ L Pro 3]EM >EM The sequence of their selectivity for MOR is EM 1 >[ D Pro 2]EM 1 =[ L Tyr 3]EM >[ D Ala 2]EM 1 =[ L Pro 3]EM >EM The results showed that, comparatively speaking, the 2 Aa was more closely related to the selectivity of EM 1 while the 3 Aa to their affinity, though the different replacement changed the AORB of EM 1 dissimilarly.
基金supported by Natural Science Foundation of Anhui Province,No.1508085MH170 National Natural Science Foundation of China,No.81472656 Natural Science Foundation Project of Anhui Province Education Department,No.KJ2017A247
文摘目的探讨内吗啡肽-1对心肌缺血再灌注损伤中PI3K/Akt信号通路的作用以及对细胞凋亡的影响。方法将50只SD雄性大鼠随机分为5组:假手术组(S组)、缺血再灌注组(IR组)、内吗啡肽-1后处理组(EM50组)、内吗啡肽-1+渥曼青霉素后处理组(EM50+Wort组)和PI3K/Akt信号通路抑制剂渥曼青霉素后处理组(Wort组)。采用结扎大鼠心脏左冠状动脉前降支30 min,再灌注120 min复制心肌缺血再灌注模型,实验期间动态监测大鼠心率、平均动脉压;再灌注结束后检测大鼠血浆乳酸脱氢酶、肌酸激酶、肌钙蛋白I、白介素-6、肿瘤坏死因子-α、氧化应激指标超氧化物歧化酶和丙二醛等生化指标,RT-PCR检测Bax和Bcl-2基因的表达情况,Western blot检测心肌组织中凋亡相关蛋白cleaved caspase-3、磷酸化Akt蛋白和总Akt蛋白的表达。结果与S组比较,IR组心率和血压降低(P<0.05);与IR组比较,EM50组心率和血压有所增高(339.94±26.65 vs 284.01±34.99;75.02±14.45 vs 55.83±20.98,P<0.05);血浆中乳酸脱氢酶、肌酸激酶、肌钙蛋白I、白介素-6、肿瘤坏死因子-α和丙二醛含量或活性下降(P<0.05),氧化应激指标超氧化物歧化酶活性增加(132.77±8.25 vs 84.10±12.42,P<0.05);p-Akt蛋白表达水平较高(0.61±0.06 vs 0.38±0.04,P<0.05),Bax基因和cleaved caspase-3蛋白表达量降低(1.70±0.39 vs 3.78±0.71;0.30±0.08 vs 0.53±0.07,P<0.05),Bcl-2基因的表达量升高(1.20±0.44 vs 0.55±0.25,P<0.05);与EM50组比较,EM50+Wort组心率和血压降低(P<0.05);血浆中乳酸脱氢酶、肌酸激酶、肌钙蛋白I、白介素-6、肿瘤坏死因子-α和丙二醛含量或活性增加(P<0.05),氧化应激指标超氧化物歧化酶活性降低(P<0.05);p-Akt蛋白表达水平较低(P<0.05),Bax基因和cleaved caspase-3蛋白表达量升高(P<0.05),Bcl-2基因表达量降低(P<0.05)。结论 EM-1后处理可调节细胞凋亡,减轻心肌缺血再灌注损伤。PI3K/Akt信号通路可能对EM-1后处理产生的心肌保护效应发挥一定的介导作用。
