Kinetic Studies of Alkaline Phosphatase from the Liver of <i>Agama agama</i> Lizard

Abstract

Kinetic studies were carried out on alkaline phosphatase (ALP) extracted from the liver of Agama agama lizard. Incubation of ALP extract with para – nitrophenyl phosphate formed the basis for the determination of enzyme activity. Spectrophotometric method was used to assay the enzyme, and the kinetic constants: Maximum velocity (V_max) and Michaelis Menten constant (Km) were calculated. The Km and V_max values were 2.5mM and 1.538 X 10^-3 ìmol/min respectively. Inhibition studies show that the enzyme activity was competitively inhibited by 0.67mM sodium hydrogen orthophosphate (NaH₂PO₄) with inhibition constant (Ki) of 2.27mM. The optimum pH of the enzyme was 9.9 and the optimum temperature was 35^OC. The enzyme exhibited linear Arrhenius relationship with  corresponding catalytic energy of activation (E_a) of 1.44KJmol^-1. This study gives an insight of the catalytic properties of ALP extracted from the liver of Agama agama lizard.

Keywords: Alkaline phosphatase, Agama agama, para – nitrophenyl phosphate (p - NPP), Arrhenius relationship, Michaelis Menten constant.