Crystallization and characterization of lipase from Penicillium cyclopium.

Abstract

A new lipolytic enzyme (Lipase III), which specifically hydrolyzed p-nitrophenyl laurate (p-NPL), was found in the culture broth of Penicillium cyclopium Ml. The enzyme was purified with an overall yield of 27% and crystallized by the addition of ammonium sulfate. The crystalline preparation gave a single band on polyacrylamide gel electrophoresis. The molecular weight of the enzyme was about 110, 000 by gel nitration. The enzyme consists of two subunits identical in molecular weight (54, 000), which was estimated by SDS-gel electorophoresis. The optimum pH and temperature for hydrolysis of p-NPL were 6.0 and 40°C, respectively. The enzyme released glycerol from olive oil more rapidly than lipases from Chromobacterium and Pseudomonas. The enzyme also rapidly hydrolyzed triglycerides in serum in the presence of surface active agents. A linear relationship was found between the absorbance at 555 nm and the amount of triglycerides in serum, when it was assayed by using lipase III, glycerol kinase, and α-glycerophosphate oxidase.