浙江蝮蛇(Agkistrodon halys Pallas)蛇毒蛋白水解酶的分离纯化及其理化性质研究

PURIFICATION OF A PROTEOLYTIC ENZYME FROM THE VENOM OF AGKISTRODON HALYS PALLAS & ITS PROPERTIES

应用DEAE-Sephadex A-50,Sephadex G-75,Sephadex G-200和QAE-SephadexA-25柱层析,从浙江蝮蛇毒中分离纯化出一种具有酪蛋白水解活性的蛋白水解酶a,称之为蛋白酶a.纯化后的蛋白酶经聚丙烯酰胺凝胶电泳和等电聚焦电泳鉴定,均呈现一条区带。等电点为6.4.用凝胶过滤及SDS-聚丙烯酰胺凝胶电泳测得其分子量为68000,糖蛋白染色法表明蛋白酶a是一糖蛋白。紫外吸收光谱表明蛋白酶a在277nm波长处有最大吸收,消光系数E_(277nm)^(0.1%)=0.681.蛋白酶a含有丰富的天冬氨酸、谷氨酸和赖氨酸。

A proteolytic enzyme from the venom of Agkstrodon halys Palla has been purified by ion-exichange chromatography on DEAE-sephadex A-50, gel-filtration on Sephadex G-75 and Sephadex G-200, and by ion-exchange chromatography on QAE-Sephadex A-25.This proteolytic enzyme (named proteinasa a) can hydrolyze casein. The purified proteinase a is homogeneous on polyacrylamide gel electrophoresis (PAGE) and on isoelectrofocusing.Its isoelectric point is 6.4.Its molecular weight is about 68,000 determined by the method of gel-filtration and SDS-PAGE. Proteinase a is a glycoprotein as shown by Schiff's stain. The ultraviolet absorption spectrum shows that proteinase a has a peak at 277nm, and its absorbance E_(277nm)^(0.1%)=0.681. The amino acid composition shows that it is rich in aspartic acid, glutamic acid and lysine.