Biochemical properties and positional specificity of Lipase from hepatopancreas of Tra catfish (Pangasius)

Abstract

Lipase from the hepatopancreas of Tra catfish (Pangasius) was precipitated by ammonium sulfate fractionation, purified by ion-exchange chromatography on DEAE cellulose and gel filtration on Sephadex G-75. On substrate triolein, purified lipase has K_m= 1.381 mM and V_max= 0.063 mM/min. The lipase was stable at a pH range of 7.0-9.0 and in temperatures of 35-50°C. At 50⁰C the enzyme loosed 44,7% activity after 120 min. The enzyme was specific for the α-positions (1, 3) of triglyceride. In bile salt solution of 0.015M NaTC, lipase activity of the enzyme increased in 3.08 folds in comparison of sample without NaTC.