广东金环蛇细胞毒素ⅩⅢ的化学组成和部分一级结构

广东金环蛇蛇毒经CM-Sephadex C-50等分离、纯化后可得细胞毒素XⅢ。本文报导该毒素的氨基酸组成与部分一级结构。用LKB4020固相多肽顺序仪一次可连续测出该毒素N端部分的25个氨基酸顺序,其顺序为A(1)n-Leu-Tyr-Gln-P(5)e-Lys-Asn-Met-Ilc-G(10)u-Cys-Ala-Gly-T(15)r-Arg-Thr-Trp-Ile-Ala-T(20)r-Val-Lys-Tyr-Gly-A(25)a-·将该毒素乙酰化以后,可封闭它的N末端及侧链上的∈-氨基,在0.2M磷酸氢二钠溶液中,用胰蛋白酶在4°C消化18小时,能释放出一个新的N端,用手工Edman降解法可测出部分氨基酸顺序,其顺序为Lys-Thr-Tyr-Ala-Tyr-Thr·细胞毒素XⅢ的氨基酸组成与Lu Hsieng-sen和LoTung-bin报导的Miami金环蛇类心脏毒素VIB的氨基酸组成极为相似,但在一级结构上有明显差异。

福建产圆斑蝰蛇(Vipera russelli siamensis)蛇毒毒性磷酯酶A2的氨基酸组成和N-末端部分氨基酸顺序的测定

福建产圆斑蝰蛇毒毒性磷酯酶A分子由18种氨基酸的124个残基组成,由此计算它们的分子量为13,883。分子中天门冬氨酸、甘氨酸、酪氨酸和半胱氨酸残基的含量较高,但只含有一个甲硫氨酸和一个色氨酸残基。用手工Edman降解方法测出毒性磷酯酶A的氨基端部分氨基酸顺序为:A(1)n-Leu-Phe-Gln-P(5)e-Ala-Arg-Met-ILe-A(10)n-Lys-Lys-Leu-Gly-A(15)-Phe20-(-)-Phe-(-)-A(20)n-Tyr-Ile。

ISOLATION AND SEQUENCE DETERMINATION OF GOOSE INSULIN

Insulins from different species are natural analogues formed in the course of evolution. Comparative studies are important both on the relationship between their structure and function and on their molecular evolution. Chicken insulin and snake insulin were studied in this laboratory and reported previously. This paper is concerned with the goose insulin. Its crystalline shape is dodecahedral, similar to that of snake insulin. Its primary structure is identical to that of duck insulin.