α-芋螺毒素TxID异构体对人类乙酰胆碱受体的活性研究  

Activities of α-conotoxin TxID isomers on human nicotinic acetylcholine receptors

作　　者：长孙东亭[1] 朱晓鹏[1] 吴勇[1] 胡远艳[1] 邴晖[1] 罗素兰[1] 

机构地区：[1]海南大学热带生物资源教育部重点实验室海口市海洋药物重点实验室,海口570228

出　　处：《中国药科大学学报》2016年第4期483-490,共8页Journal of China Pharmaceutical University

基　　金：国家自然科学基金重点国际合作项目资助(No.81420108028);国家自然科学基金资助项目(No.41366002);海口市重点科技计划项目资助(No.2013-16);长江学者和创新团队发展计划资助项目(No.IRT-15R15)~~

摘　　要：研究α-芋螺毒素Tx ID 3个二硫键异构体对人类α3β4与α6/α3β4乙酰胆碱受体的阻断活性。采用Fmoc固相合成法,分别合成α-芋螺毒素Tx ID的3个二硫键异构体的线性肽,利用2步氧化法进行氧化折叠,获得具有定点连接二硫键的异构体多肽。利用非洲爪蟾卵母细胞表达人类α3β4与α6/α3β4乙酰胆碱受体亚型,测定3个异构体对该乙酰胆碱受体的电流与洗脱速率的影响情况。α-芋螺毒素Tx ID的3个二硫键异构体对人类α3β4与α6/α3β4乙酰胆碱受体亚型的阻断活性差异很大,阻断是可逆的,洗脱速率较快。其中具有天然构象的球状异构体活性最强,其半数阻断剂量(IC50)仅约为9.3 nmol/L;其次是带状异构体具有很微弱的抑制活性,其IC50大于5μmol/L;而珠子状异构体几乎没有阻断活性,其IC50大于10μmol/L。成功合成了α-芋螺毒素Tx ID的3个二硫键异构体,并获知了3个二硫键异构体分别对人类α3β4与α6/α3β4乙酰胆碱受体亚型的阻断活性,为α-芋螺毒素Tx ID后续海洋新药研发提供理论基础。To investigate activities of three isomers of α-conotoxin TxID on human α3 β4 and α6/α3 β4 nicotinic acetylcholine receptors（nAChRs）. The three isomers of α-eonotoxin TxID were synthesized using solid phase Fmoc chemistry and fully folded by two-step oxidations. Human α3 β4 and α6/α3 β4 nAChRs were expressed in oocytes of Xenopus laevis, which were used for bioassay of the three isomers, including inhibition and washout reversibility. There were obvious differences between the inhibition potency of each isomers at human α3 β4 and α6/α3 β4 nAChRs. The blocking was reversible and washout rapidly. The most potent isomer is the globular form with an IC50 of 9.3 nmol/L on human α3 β4 and α6/α3 β4nAChRs respectively. The 2nd potent isomer was the ribbon form with much less potency, which had an IC50 of 〉 5 μmol/L. The bead isomer had little or no block on human α3β4 and α6/α3 β4 nAChRs with an IC50 of 〉 10 μmol/L. The three isomers of α-eonotoxin TxID were synthesized successfully with two pairs of desired disulfide bond. Inhibition activities of the 3 isomers on human α3β4 and α6/α3 β4 nAChRs were obtained respectively, which would be basis for new marine drug development of α-eonotoxin TxID.

关 键 词：α-芋螺毒素Tx ID 二硫键异构体 多肽人工合成 人类α3β4乙酰胆碱受体 人类α6/α3β4乙酰胆碱受体 

分 类 号：R91[医药卫生—药学]