地鳖纤溶活性蛋白的纯化及性质研究

通过硫酸铵分段沉淀、DEAE-纤维素柱和SephadexG-75柱层析从雌地鳖(Eupolyphagesinensiswalker)体内分离纯化到一种相对分子质量约为41.3kD的纤溶活性蛋白,纤维蛋白平板测定表明,该蛋白具有纤溶作用,经SDS-PAGE电泳显示为一条带,含糖量为10.5%。其水解纤维蛋白的比活力为547.86u/mg。该成分受蛋白抑制剂和丝氨酸蛋白酶抑制剂PMSF的抑制,但EDTA对其影响不大,提示该成分属于丝氨酸蛋白酶类。该成分在40℃下基本稳定,最适温度40℃,最适pH为8.0,其激活纤维蛋白溶解酶(PLG)的机制与尿激酶(UK)有一定区别。推测其可能是一种新的地鳖纤溶酶组分。

Purification and Biochemical Character of a Fibrinolytic Protein from Eupolyphaga sinensis

A novel of fibrinolytic protein has been separated and purified by ammonium sulfate fractionation, DEAE-cellulose and SephadexG-75 Column chromatography from the tissue of the female Eupolyphaga sinensis in the paper. The protein showed an apparent molecular weight of 41.3 kD on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. In addition, it includes 10.5% sugar. Its specific activity to hydrolyze fibrin was 547.86 u/mg. The enzyme activity was inhibited by Mg2+, Ca2+, protein inhibitors, such as 8mol/L urea and 1% beta-mercaptoethanol, and serine protease inhibitor such as phenylmethanesulfonyl fluoride (PMSF), but wasn't inhibited by Na+, K+ and ethylenediaminotetraacetic acid (EDTA). The protein was stable under 40 degrees C and it's optimal temperature was also 40 degrees C. It's optimal pH was 8.0. It showed a different way between the activity and UK when they degrade the plasminogen. Based on all the messages the protein can be suggested to be a novel fibrinolytic protein. There have been no such component of fiberinolytic enzyme from Eupolyphaga sinensis walker reported yet.