Kinetic study of hepatic β-glucuronidase in the Indian major carp, Labeo rohita (Hamilton)

Abstract

Liver is the metabolic factory and contains several valuable enzymes that catalyze biochemical reactions. β-glucuronidase is one of the well-known lysozymes that participates in the carbohydrate metabolism in the tissues of various vertebrates. In the present study, an attempt was made to study the kinetic properties of hepatic β-glucuronidase of the Indian major carp (IMC), Labeo rohita. It was observed that the enzyme activity increased largely at pH 5 (0.1M acetate buffer) when exposed to 38°C. However, the maximum activity was noticed at 52°C and later it started declined up to 70°C. It was also observed that with time the enzyme activity increased until substrate was completely used up. It has been concluded that it is a heat stable enzyme and cannot be destroyed at room temperature. Enzyme activity was observed to increase in response to increase in enzyme and substrate concentrations. The reaction velocity maxima (Vmax) and Michaelis constant (Km) were recorded using Lineweaver-Burk plot that was 18.182μg/h and 2.907mM, respectively.