AMINO ACID COMPOSITION AND SPECIFICITY OF A KERATINASE OF TRICHOPHYTON MENTAGROPHYTES

An extracellular keratinase with a specific activity of 34.0 KU/mg was purified from a culture filtrate of Trichophyton mentagrophytes with a recovery of 20%. The keratinase appeared to be homogeneous on disc polyacrylamide electrophoresis and analytical ultracentrifugation. The pure enzyme had an isoelectric point of pH 9.4. The antigenic components of the pure enzyme and the culture filtrate appeared to be identical on immunodiffusion analysis. Amino acid composition was determined and no carbohydrate was found in the pure enzyme. The pure keratinase hydrolyzed hair, casein, collagen, elastin, fibrin, fibrinogen, gelatin, hemoglobin, insulin, ovalbumin, 47 amides and peptides of known structure. The pure enzyme, however, did not hydrolyze 37 esters, amides, peptides, and polypeptides. © 1969.