与光系统Ⅱ颗粒结合的蛋白酶的进一步分析

FURTHER ANALYSIS OF PROTEASES ASSOCIATED WITH PHOTOSYSTEM Ⅱ PARTICLES

依次用三种溶液抽提处理菠菜光系统Ⅱ颗粒，离心后分别得到主要含１８ｋＤ，２４ｋＤ和３３ｋＤ水溶性蛋白的三种抽提液，利用ＳＤＳ聚丙烯酰胺凝胶电泳检测到前两种抽提液中均含蛋白酶．抽提液分别温育时，１８ｋＤ蛋白被降解而产生１７．１ｋＤ，１６ｋＤ，１４．４ｋＤ，１３．５ｋＤ和１２ｋＤ片段；２４ｋＤ蛋白被降解成２２ｋＤ，２０ｋＤ和１８ｋＤ．抑制剂实验表明。

The three extrinsic soluble proteins(18kD,24kD and 33kD proteins) of the PS Ⅱ water oxidation complex were obtained by treating spinach PS Ⅱ particles with three buffers and centrifugation in step.Some proteolytic activity was detected in the first two extracts by SDS polyacrylamide gel electrophoresis.When the two extracts were kept at 35℃,the 18kD and 24kD proteins were degraded,generating polypeptides of 17.1,16,14.4,13.5 and 12kD from 18kD protein and 22kD,20kD and 18kD from 24kD protein,respectively.The result of inhibition suggests that there is some protease which degrade inactive protein in the extracts.