FIBRINOLYTIC PROTEASES FROM THE GUT OF LARVAE OF FLESH FLY, BOETTCHERISCA PEREGRINA (DIPTERA: SARCOPHAGAE): PURIFICATION AND CHARACTERIZATION

Abstract

Abstract Three fibrinolytic proteases, which were designated as BPGFF'l, 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 am 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.