Replacement of the interchain disulfide bridge-forming amino acids A7 and B7 by glutamate impairs the structure and activity of insulin

	Replacement of the interchain disulfide bridge-forming amino acids A7 and B7 by glutamate impairs the structure and activity of insulin
	Guo, ZY; Jia, XY; Feng, YM
刊名	BIOLOGICAL CHEMISTRY
	2004
卷号	385 期号:12 页码:1171-1175
关键词	activity disulfide bond folding insulin structure
通讯作者	Feng, YM (reprint author), Chinese Acad Sci, Key Lab Proteom, Inst Biochem & Cell Biol, Shanghai Inst Biol Sci, Shanghai 200031, Peoples R China.,fengym@sunm.shcnc.ac.cn
英文摘要	Insulin contains three disulfide bonds, one intrachain bond, A6-A11, and two interchain bonds, A7-B7 and A20-B19. Site-directed mutagenesis results (the two cysteine residues of disulfide A7-B7 were replaced by serine) showed that disulfide A7-B7 is crucial to both the structure and activity of insulin. However, chemical modification results showed that the insulin analogs still retained relatively high biological activity when A7Cys and B7Cys were modified by chemical groups with a negative charge. Did the negative charge of the modification groups restore the loss of activity and/or the disturbance of structure of these insulin analogs caused by deletion of disulfide A7-B7? To answer this question, an insulin analog with both A7Cys and B7Cys replaced by Glu, which has a long side-chain and a negative charge, was prepared by protein engineering, and its structure and activity were analyzed. Both the structure and activity of the present analog are very similar to that of the mutant with disulfide A7-B7 replaced by Ser, but significantly different from that of wild-type insulin. The present results suggest that removal of disulfide A7-B7 will result in serious loss of biological activity and the native conformation of insulin, even if the disulfide is replaced by residues with a negative charge.
学科主题	Biochemistry & Molecular Biology
类目[WOS]	Biochemistry & Molecular Biology
关键词[WOS]	FOLDING INTERMEDIATE ; ANALOG LACKING ; IGF-I ; PRECURSOR ; BONDS ; PROINSULIN ; EXPRESSION ; MODEL
收录类别	SCI
语种	英语
WOS记录号	WOS:000226032300006
内容类型	期刊论文
版本	出版稿
源URL	[http://202.127.25.143/handle/331003/2160]
专题	上海生化细胞研究所_上海生科院生化细胞研究所
推荐引用方式 GB/T 7714	Guo, ZY,Jia, XY,Feng, YM. Replacement of the interchain disulfide bridge-forming amino acids A7 and B7 by glutamate impairs the structure and activity of insulin[J]. BIOLOGICAL CHEMISTRY,2004,385(12):1171-1175.
APA	Guo, ZY,Jia, XY,&Feng, YM.(2004).Replacement of the interchain disulfide bridge-forming amino acids A7 and B7 by glutamate impairs the structure and activity of insulin.BIOLOGICAL CHEMISTRY,385(12),1171-1175.
MLA	Guo, ZY,et al."Replacement of the interchain disulfide bridge-forming amino acids A7 and B7 by glutamate impairs the structure and activity of insulin".BIOLOGICAL CHEMISTRY 385.12(2004):1171-1175.