PURIFICATION AND CHARACTERIZATION OF CUTICLE-DEGRADING PROTEASE FROM ENTOMOPATHOGENIC FUNGUS,METARHIZIUM ANISOPLIAE
绿僵菌分解昆虫外壳蛋白酶MAP-21的纯化与特性

The cuticle-degrading proteases from entomopathogensis fungus, Melarhizium anisopliae,were induced by adding cicada exuviae, colloidal chitin, shrimp cuticle, maggot cuticle, horsefly cuticle and silkworm chrysalis cuticle into minimal medium. After ultrafiltration, Ultrogel AcA 54 column and IEF, a protease designated as MAP-21 with Mr 27 kD, and pI 7.6 were purified. It was shown that the recognition site of MAP-21 was Arg, PMSF and TLCK could inhibited the activity of this protease, indicating that there were Ser and His residues in the active center. The inhibitors to trypsin, leupeptin antipain and STI also repressed the activity of MAP-21, while chymostatin, TPCK and elastatinal TEI were shown no inhibition to its activity, demonstrating that, MAP-21 was a trypsinlike protease. Other properties of MAP-21 were also reported.