Purification and properties of lipase from Tilapia intestine - Digestive enzyme of Tilapia-VI

Abstract

Lipase of the intestine of Tilapia nilotica was purified by ammonium sulfate precipitation, followed by ion-exchange chromatography (DEAE-cellulose), chromatofocusing (Polyexchanger PBE 94), and gel filtration (Sephadex G-100). The lipase was found to be a single band when examined by electrophoresis. The specific activity of the purified enzyme was 177 times higher than that of the crude extract. The lipase had a molecular weight of 46,000, showed the highest activity at pH 7.5 and 35°C, and was stable at pH 6.5-8.5 and below 40°C. The Km of the enzyme for olive oil was calculated to be 0.7 mM. Its activity was inhibited by Cu2+, Cd2+, Ni2+, Hg2+, PCMB, and CH2ICOOH. This enzyme specifically digested Tributyrin and Tricaproin, whereas it digested 1,2-diolein and 1-monoolein more than 1,3-diolein and 2-monoolein. The enzyme well decomposed soybean oil and coconut oil.