【摘要】 从以富含纤维蛋白的血凝块为食物的棕尾别麻蝇幼虫肠道浸提液中分离纯化出 3种具有溶纤活性的蛋白酶 ,分别命名为BPGFP1,BPGFP2和BPGFP3。其中 ,BPGFP1由两个分子量分别为 32 0 0 0和 30 0 0 0的亚基组成。BPGFP2和BPGFP3均为单体 ,分子量分别为 4 0 0 0 0和 2 80 0 0。这三种蛋白酶具有相似的底物特异性和抑制剂特性。三种蛋白酶均能降解溶纤活性蛋白酶的特异底物纤维蛋白、ChromzymP、ChromzymUK和S 2 2 88。三种酶还能够强烈降解类胰蛋白酶专一底物Bz Phe ValArgNA ,cBzGly Pro ArgNA ,Bz Pro Phe ArgNA和Bz Val Gly ArgNA。PMSF ,STI,LBTI和SBBI能够对三种蛋白酶活性有极强的抑制作用。三种溶纤活性蛋白酶均在pH 9.0～ 10 .0范围内表现出较高活性。更多还原

【Abstract】 Three fibrinolytic proteases, which were designated as BPGFP1, BPGFP2 and BPGFP3 individually, were purified from the gut extract of larvae of Boettcherisca peregrina fed on artificial diet containing fibrin rich pig blood coagulated block. BPGFP1 consists of two subunits with MW 32 000 and 30 000. Both BPGFP2 and BPGFP3 are monomer with MW 40 000 and 28 000, respectively. These three proteases are similar in substrate and inhibitor specificity. All of them possess high activities against fibrinolytic protease specific substrates such as fibrin, Chromzym P, Chromzym UK and S 2288. They also strongly hydrolyze trypsin specific substrates Bz Phe Val Arg NA, cBz Gly Pro Arg NA, Bz Pro Phe Arg NA and Bz Val Gly Arg NA. PMSF, STI, LBTI and SBBI can inhibit activity of these proteases. Activities of these three fibrinolytic proteases were found to be maximal at alkaline range of pH 9.0～10.0.更多还原