摘要
根据棉铃虫Ｈｅｌｉｃｏｖｅｒｐａａｒｍｉｇｅｒａ（Ｈｕｂｎｅｒ）中肠酶液对蛋白酶专性底物在不同ｐＨ下的水解作用，棉铃虫中肠的３种丝氨酸蛋白酶得到鉴定。它们是：强碱性类胰蛋白酶，水解α－Ｎ－苯甲酰－ＤＬ－精氨酸－ｐ－硝基苯胺的最适ｐＨ在１０．５０以上；弱碱件类胰蛋白酶，水解ｐ－甲苯磺酰－Ｌ－精氨酸甲酯的最适ｐＨ为８．５０～９．００；类胰凝乳蛋白酶，水解Ｎ－苯甲酰－Ｌ酪氨酸乙酯的最适ｐＨ亦为８．５０～９．００。中肠总蛋白酶活性用偶氮酪蛋白测定，最适ｐＨ亦在１０．５０以上。Ｃａ２＋对昆虫蛋白酶无影响，Ｍｇ２＋仅对弱碱性类胰蛋白酶有激活作用。对苯甲基磺酰氟和甲基磺酰－Ｌ－赖氨酸氯甲基酮对弱碱性类胰蛋白酶的抑制作用较强，而对强碱性类胰蛋白酶的抑制作用较弱。甲基磺酰－Ｌ－苯丙氨酸氯甲基酮除能抑制类胰凝乳蛋白酶外，还能激活弱碱性类胰蛋白酶。对牛胰蛋白酶有强抑制作用的卵粘蛋白抑制剂对昆虫蛋白酶却无抑制作用。大豆胰蛋白酶抑制剂对该虫的３种丝氨酸蛋白酶均有强的抑制作用。
The activities of three serine proteases in the midgut of Helicoperpaarmigera larvae were partially characterized.The enzymes were an active alkalinetrypsin-like enzyme with maximal hydrolysis of benzoyl arginine p-nitroanilideat pH 10.50 or higher,a weak alkaline trypsin-like enzyme with maximalhydrolysis of tosyl-L-arginine methyl ester at pH 8.50 -9. 00,and achymotrypsin-like enzyme with maximal hydrolysis of benzoyl-L-tyrosine ethylester at pH 8. 50-9. 00.Total proteolysis,measured by using azocasein, hadamaximal activity at pH 10. 50 or higher.Ca2+ had no activation effect on larvalproteases,but Mg2+ activated the weak alkaline trypsin-like enzyme.The inhibition with phenyl methyl sulfonyl fluoride and tosyl-L-lysine chloromethyl ketoneto the weak alkaline trypsin-like enzyme activity was greater than that to the active alkaline trypsin-like enzyme activity.The tosyl-L-phenylalinine chloromethyl ketone was not only the inhibitor of the chymotrypsin-like enzyme,but also the activator of the weak alkaline trypsin-like enzyme.Comparison between the insect protease and bovine counterpart protease revealed difference ininhibitor sensitivity.Ovomucoid trypsin inhibitor that inhibited bovine trypsinhad no effect on insect trypsin-like enzymes.Soybean trypsin inhibitor had greatinhibition on both insect and bovine proteases.
出处
《昆虫学报》
CAS
CSCD
北大核心
1996年第1期7-14,共8页
Acta Entomologica Sinica
基金
国家自然科学基金
关键词
棉铃虫
蛋白酶
抑制剂
Helicoverpa armigera, protease,activator,inhibitor
