Abstract

Metalloprotease was detected in the fruit body of the edible mushroom Flammulina velutipe. Inactivation of the metalloprotease reduced mycelial growth signicantly, implying that metalliprotease is important for growth. A neutral metalloprotease was purified by hydrophobic, gel filtration, and anion exchange chromatography. The M_r of the protein was determined to be 30,000 by SDS-PAGE and 33,000 by gel filtration on a Sepjadex G-150 column, indicating that it is a monomer. Its first 11 N-terminal amino acids (P-Q-V-K-T-W-D-L-A) did not show any homology with any known protein in Database(GENEBANK, Swissprot). The enzyme was inhibited by EDTA, 1, 10-phenanthroline, and phosphoamidon but not by inhibitors specific for serine, aspartate and custeine protease. Addition of Zn^2+ and Co^2+ reversed the inhibition caused by 1,10-ohenanthroline. This protease hydrolyzed human fivrinogen, fibrin, azoalbumin, and azocasein as substrates. It showed cleavage preference for hydrophobic residues among tested synthetic substrates.

• Keywords: Metalloprotease; fibrinolytic protease; fruit body; 1;10-phenanthroline; Flammulina velutipes