PURIFICATION AND PARTIAL CHARACTERIZATION OF A NOVEL TRYPSIN-LIKE CYSTEINE PROTEASE FROM METARHIZIUM-ANISOPLIAE

Trypsin-like enzymes from the entomopathogenic fungus Metarhizium anis opliae have been characterised. Two proteases with tryptic activity we re purified by narrow range isoelectric focussing and affinity chromat ography. One of these proteases, with an isoelectric point of 5.4 and a molecular mass of 28.8 kDa is a 'classical' trypsin belonging to the serine protease class. The other protease, with an isoelectric point of 4.6 and a molecular mass of 26.7 kDa, demonstrates trypsin-like spe cificity but, on the basis of inhibition and activation studies, belon gs to the cysteine protease family and as such is the first fungal pro tease to be found of this type. The amino acid composition, kinetic co nstants and activity against proteinaceous substrates, including locus t cuticle have been determined.