B8Gly在胰岛素结构模体中的可能作用  

Possible Role of B8Gly in Insulin Structural Motif

作　　者：张弘[1] 唐月华[1] 冯佑民[1] 

机构地区：[1]中国科学院上海生命科学研究院,上海生物化学研究所,分子生物学国家重点实验室,上海200031

出　　处：《生物化学与生物物理学报》2000年第5期480-484,共5页

基　　金：国家高技术"863"计划资助项目!No .863 10 3 13 0 1 0 1;中国科学院重点基础研究项目 !No .KJ95 1 B1 60 6&&

摘　　要：在胰岛素结构模体n1 Cys Gly X10 Cys n2 Cys Cys X3 Cys X8 Cys n3中 ,有 7个绝对保守的氨基酸残基 ,只有位于B8位的是Gly。通过定点突变将其改变为Ala,得到[B8Ala]人胰岛素 ,其受体结合能力和体内生物活力分别为天然猪胰岛素的 2 .5 %和 10 %。[B8Ala]人胰岛素和重组人胰岛素的远紫外圆二色谱比较表明 ,[B8Ala]人胰岛素的α 螺旋的相对含量有一定降低 ,说明胰岛素结构模体中的B8Gly是不可被取代的。In the insulin structural motif n1-Cys-Gly-X10-Cys-n2-Cys-Cys-X3-Cys -X8-Cys-n3, there are seven absolutely conserved amino acid residues, and the on ly Gly is at position B8. When B8Gly was substituted with Ala by means of site- d irected mutagenesis, a mutant insulin, [B8Ala]human insulin was obtaine d. The r eceptor binding capacity and in vivo biological activity of the [B8Ala] human ins ulin were about 2.5% and 10% of native porcine insulin, respectively. The far-U V circular dichroism (CD) spectra of [B8Ala]human insulin and human insuli n showed that the relative content of α-helix in the mutant somewhat decreased . The r esults indicate that the B8Gly in the insulin structural motif is unreplaceable.

关 键 词：胰岛素结构模板 胰岛素突变体 人胰岛素 

分 类 号：Q578[生物学—生物化学]