［B1－Ala，B2－Ala］－胰岛素：受体结合特性及生物活力研究  

The ReceptorBinding and Biological Activity of [B1-Ala, B2-Ala]-insulin

作　　者：朱尚权[1] 张新堂[1] 徐明华[1] 叶莺[1] 郑汉其[1] 

机构地区：[1]中国科学院上海生物化学研究所,香港中文大学生物化学系

出　　处：《生物化学与生物物理学报》1996年第3期250-256,共7页

摘　　要：本文报道了［Ｂ１～Ａｌａ，Ｂ２－Ａｌａ］－胰岛素与人胎盘细胞膜胰岛素受体结合的特性和体外生物活力，并与胰岛素进行比较。在３７℃和杆菌肽存在下，１２５Ｉ－［Ｂ１－Ａｌａ，Ｂ２－Ａｌａ］－胰岛素和１２５Ｉ－胰岛素与人胎盘细胞膜作用依赖于反应时间，反应６分钟到达平衡，此时，［Ｂ１－Ａｌａ，Ｂ２－Ａｌａ］－胰岛素和胰岛素与胰岛素受体的最大结合分别为每毫克膜蛋白结合６．４４ｆｍｏｌ和３．４７ｆｍｏｌ：达到平衡一半所需时间（Ｔ１／２）分别为１９秒和２５秒。用１２５Ｉ－［Ｂ１－Ａｌａ，Ｂ２－Ａｌａ］－胰岛素作为放射配体进行竞争性结合研究，从ＩＣ（５０）得［Ｂ１－Ａｌａ，Ｂ２－Ａｌａ］胰岛素的受体结合活力为胰岛素的１３９．６％。Ｓｃａｔｏｈａｒｄ分析求得；［Ｂ１－Ａｌａ，Ｂ２－Ａｌａ］－胰岛素与高亲和和低亲和结合位点的结合常数在４℃时分别为５．８８×１０８Ｌ／ｍｏｌ和７．６３×１０５Ｌ／ｍｏｌ，而胰岛素分别为４．８３×１０８Ｌ／ｍｏｌ和３．３９×１０５Ｌ／ｍｏｌ。促脂肪细胞生成脂的实验表明：［Ｂ１－Ａｌａ，Ｂ２－Ａｌａ］－胰岛素的活力为胰岛素的１３０％。The receptor binding properties with human placental membrane (HPM) and the in vitro biological activity of an insulin analogue, [B1-Ala, B2-Ala]-insulin were investigated in detail and compared with those of insulin. It was found that the binding of 125I-[B1-Ala, B2-Ala]-insulin and 125I-insulin to HPM was time dependent reaching equilibrium after 6 min at 37℃ in the presence of bacitracin with an equilibrium maximum binding of 6.44 fmol/mg protein for [B1-Ala, B2-Ala]-insulin and 3.47 fmol/mg protein for insulin. The half time(T1/2) to reach equilibrium was 19 seconds for [B1-Ala, B2-Ala]-insulin and 25 seconds for insulin. [B1-Ala, B2-Ala]-insulin and insulin competed with specific 125I-[B1-Ala, B2-Ala]-insulin in a dose-dependent manner. From 1C50, the receptor binding activity of [B1-Ala, B2-Ala]-insulin was 139. 6% compared with that of insulin. Scatchard analysis revealed that the receptor association constants of [B1-Ala, B2-Ala]-insulin in HPM at 4℃ were 5.88 ×108L/mol and 7.63 × 105L/mol respectively, while those of insulin were 4.83 × 108L/mol and 3.39 × 105L/mol respectively. The in vitro activity of [B1-Ala, B2-Ala]-insulin was 130% of that of insulin in terms of lipogenesis in rat adipocytes.

关 键 词：Bl-Ala B2-Ala 胰岛素 受体结合 生物活力 

分 类 号：Q578.02[生物学—生物化学]