Abstract
It had been found that in one of lipase [EC 3. 1. 1. 3] from Mucor javanicus the hydrolysis of fats was accelerated by bile salts. The lipase was purified about 20-fold from the original powder (about 100-fold from the culture broth) by ammonium sulfate precipitation, chromatography on Sephadex G-75, CM-cellulose, and Sephadex G-200. Recovery of the activity was about 18%. The purified enzyme was homogeneous on electrophoresis. Optimum pH for hydrolysis of olive oil was 7.0 by the assay method using a PVA system and 7.5 by that using a shaken system. Optimum temperature was 40°. The enzyme was stable below 30°. It was strongly inhibited by Ag+, Hg2+, and N-bromosuccinimide (NBS). The apparent I50 value of NBS was 1.4×10-4M, that of both iodine and sodium lauryl sulfate were 2.4×10-3M. The lipase hydrolyzed tricaprylin most efficiently, and next to it tricaprin and trilaurin. The Michaelis constant (Km) for triglycerides agreed closely with the substrate specificity.
