眼镜王蛇（食蛇者眼镜蛇）毒液中的一种蛋白酶：氧化胰岛素B链的纯化、特性及底物特异性

A protease in the venom of king cobra (Ophiophagus hannah): purification, characterization and substrate specificity on oxidized insulin B-chain.

作者信息

Yamakawa Y, Omori-Satoh T

机构信息

Department of Applied Immunology, National Institute of Health, Tokyo, Japan.

出版信息

Toxicon. 1988;26(12):1145-55. doi: 10.1016/0041-0101(88)90299-1.

DOI:10.1016/0041-0101(88)90299-1

PMID:3070833

Abstract

A protease in the venom of Ophiophagus hannah (king cobra) has been purified to a homogeneous state by successive chromatographies on Sephadex G-100 superfine, DEAE-cellulose, hydroxyapatite and CM-polyvinylalcohol copolymer columns. The mol.wt as determined by SDS-PAGE and gel filtration was approximately 70,000. The purified enzyme possessed a specific activity approximately 1/25 that of crystalline trypsin, whereas it had no hemorrhagic activity. The substrate specificity was determined using oxidized insulin B-chain as a substrate; the enzyme cleaved the Asn3-Gln4, Gln4-His5, His10-Leu11, Ala14-Leu15 and Tyr16-Leu17 positions. The sites cleaved by the protease were compared to proteases from other snake venoms.

摘要

通过在Sephadex G - 100超细微粒、DEAE - 纤维素、羟基磷灰石和CM - 聚乙烯醇共聚物柱上连续进行色谱分离，将眼镜王蛇毒液中的一种蛋白酶纯化至均一状态。通过SDS - PAGE和凝胶过滤测定的分子量约为70,000。纯化后的酶比活性约为结晶胰蛋白酶的1/25，且无出血活性。以氧化胰岛素B链为底物测定底物特异性；该酶可切割Asn3 - Gln4、Gln4 - His5、His10 - Leu11、Ala14 - Leu15和Tyr16 - Leu17位点。将该蛋白酶切割的位点与其他蛇毒中的蛋白酶进行了比较。