[#2001-05] Purification and Characterization of Mushroom Proteases. 4. Maitake, Grifola frondosa, Emi Kenjo et al.

Recently, proteolytic enzymes are becoming increasingly important especially in the food industries.” Today the major uses of proteases occur in production and processing of diverse products such as cheese,” ⁶⁾ baked goods,⁷‘  beer,⁹‘ ^I” flavor ingredients” and therapeutic diets.”‘ The enzyme-based processes are continuing to grow and expand, which inevitably requires new, improved enzymes with unique substrate specificities or stability characteristics. In order to find and characterize new proteases, we have investigated proteolytic activity in mushrooms using a series of synthetic peptide substrates having the sequence Boc-tetrapeptide-pNA (Boc, t­butyloxycarbonyl; pNA, p-nitroanilide). In the previous papers, we have reported on the isolation and characteri­zation of endopeptidases of shiitake (Lentinus edodes),’ shirotamogitake (Lyophyllum ulmarium)”⁾ and shimeji mushroom (Lyophyllum aggregatum).’ In the present experiment, we found endopeptidase activity hydrolyzing Boc-Ala-Ala-Pro-Phe-pNA in fruit body of maitake mush­room, Grifola frondosa. This report describes the isolation and characterization of the enzyme.