The lysine-specific proteinase from Armillaria mellea is a member of a novel class of metalloendopeptidases located in basidiomycetes

The fruiting body of the basidiomycete fungus Armillaria mellea produces a lysine-specific proteinase which exhibits both potent fibrinolytic activity and a remarkable resistance to denaturing agents. An improved purification protocol has been developed for this enzyme and the sequence of the 26 N-t erminal amino acid residues of the pure protein has been determined by gas- phase sequencing. Searches of the SwissProt database showed that the N-term inal sequence of A. mellea proteinase is highly similar to those of lysine- specific metalloendopeptidases from the basidiomycetes Grifola frondosa and Pleurotus ostreatus. These results support the view that the A. mellea pro teinase is a member of a novel class of lysine-specific metalloendopeptidas es which may be exclusive to basidiomycete fungi. (C) 1999 Academic Press.