Comparative electrophoresis and some properties of alkaline proteinases produced by Monascus spp.

Abstract

Some strains in the genus Monascus secreted extracellular alkaline proteinases on a wheat bran medium, along with propagation of cells. Crude enzymes prepared from six strains of five species and one variety of Monascus were separated by polyacrylamide slab gel electrophoresis and their activities were visualized with a printing technique on a casein-containing gel. We found that their proteinase activities were based on at least three different proteins which occurred commonly in all the strains examined. These enzymes were completely inhibited by phenylmethylsulfonyl fluoride and were insensitive to chelating and SH reagents. They were characterized as serine proteinases different from chymotrypsin- or trypsin-type enzymes by their insensitivity to the affinity-labeling reagents, N-α-tosyl-L-lysyl chloromethyl ketone and N-tosyl-L-phenylalanyl chloromethyl ketone.