南美白对虾虾头主要自溶酶的分离纯化及鉴定

以水解试验为导向,采用硫酸铵分级沉淀、Sephadex G-100凝胶层析、DEAE-DE52阴离子交换柱层析等手段分离纯化南美白对虾虾头主要自溶酶,同时采用抑制剂试验及SDS-PAGE对纯化蛋白酶进行鉴定。结果表明,南美白对虾虾头主要自溶酶经过纯化后比活力高达2.2×106U/g,纯化倍数为96.90。丝氨酸蛋白酶抑制剂苯甲基磺酰氟(PMSF)对主要自溶酶的抑制率高达91.3%;SDS-PAGE显示该酶为单一电泳带,且在电泳中与标准胰蛋白酶移动距离相同,表明南美白对虾虾头内的主要自溶酶为胰蛋白酶。

Purification and Identification of Major Autoenzyme from the Head of White Shrimp (Penaeus vannamei)

With hydrolysis test as an orientation,the major autoenzyme was purified from the head of white shrimp(Penaeus vannamei) by sulfate precipitation,gel filtration on Sephadex G-100 followed by ion-exchange chromatography DEAE-DE52.The autoenzyme was then identified by inhibitor tests and SDS-PAGE analysis.The results showed the major autoenzyme from the head of white shrimp had a specific activity of 2.2×106 U/g with a 96.90-fold increase over that of the crude enzyme extract.This autoenzyme was inhibited by serine protease inhibitor phenyl methyl sulfonyl fluoride(PMSF) with the inhibition rate being 91.3%,and illustrated as a single band in SDS-PAGE with the same distance as that of standard trypsin.These results indicated that trypsin was the major autoenzyme in the head of white shrimp.