摘要
将去Ｂ链羧端三肽人胰岛素原基因克隆到表达质粒ｐＢＶ２２０上，在大肠杆菌系统中经温度诱导表达，表达产物占细胞总蛋白量的１２％，表达产物经ＳｅｐｈａｄｅｘＧ－５０柱层析分离以及胰蛋白酶和羧肽酶Ｂ的酶促转化等步骤，可得到去Ｂ链羧端三肽人胰岛素，其纯度达９３％，其氨基酸组成与预期值相符，但其受体结合活性仅是标准猪胰岛素的４５％．
Des-terpeptide of C-terminal (B28─30) human proinsulin gene was recombinated to the expression vector pBV220 and expressed in E. coli, induced by temperature. The expression level accounted for 12% of total bacterial proteins. The expression product was purified by Sephadex G-50 gel filtration and converted to Des-terpeptide of C-terminal human insulin (DTEI) by trypsin and carboxypeptidase B. DTEI , purified by DEAE-Sephadex A-25, has an expected amino acid composition, but the receptor binding activity is only 45% as compared with standard porcine insulin.
基金
北京大学蛋白质工程国家重点实验室资助
关键词
胰岛素
去B链羧端三肽
人胰岛素
提纯
性质
Des-terpeptide of C-terminal human insulin, Receptor binding activity
