中文摘要：

采用30%~50%饱和度的硫酸铵沉淀、凝胶层析脱盐及聚丙烯酰胺梯度凝胶电泳,再通过直接切胶后用回收槽电洗脱回收的方法,从暗诱导衰老小麦叶片中分离得到了1种耐热的蛋白水解酶。该酶具有良好的热稳定性,且表现出相当宽的pH稳定范围。该酶的最适温度为50℃,最适pH为8。分离得到的酶液在0-60℃处理1 h后,酶活性无明显变化,70℃处理1 h后仍有部分活性。酸性蛋白酶抑制剂、金属蛋白酶抑制剂和半胱氨酸蛋白酶抑制剂都不能抑制该蛋白水解酶的活性,但丝氨酸蛋白酶抑制剂能部分抑制该酶的活性。

英文摘要：

A kind of thermostable protease from dark-induced senescence wheat leaves was isolated by ammonium sulfate precipitation （from 30% to 50% saturation） , then by gradient-polyacrylamide gel electrophoresis after desalted by gel filtration, finally by electro-eluted out from the gel slices cut. The results showed that the protease was rather stable to heat and pH. The optimum temperature and pH of the enzyme were 50 ℃ and 8, respectively. The activity of the isolated protease had no evident change when the enzyme incubated from 0 ℃ to 60 ℃ for 1 h. Incubated at 70 ℃ for 1 h, it still had a part of activity. The enzyme could not be inhibited by acidic proteinase inhibitor, metall proteinase inhibitor and cysteine proteinase inhibitor, but partly inactivated by serine proteinase inhibitor.