Easy to search. Easy to read. Easy to cite with credible sources.
Year: 2011 | Volume: 6 | Issue: 1 | Page No.: 65 - 73
V.O. Njoku, P.C. Chikezie, M.A. Kaoje, C.C. Monago and A.A. Uwakwe
Abstract
Studies were carried out to ascertain some kinetic properties of alkaline phosphatase (ALP) extracted from Lepus townsendii liver. Incubation of ALP extract with 4-nitrophenylphosphate (4-NPP) in glycine-NaOH buffer mixture at 37°C for 30 min formed the basis for determination of enzyme activity. Spectrophotometric method was used to assay for the enzyme activity for 30 min and the kinetic constants-maximum enzyme velocity (Vmax) and Michealis-Menten constant (Km) were evaluated. The Km and Vmax values were 0.5x10-3 M and 20x10-6 M min-1, respectively. Inhibition studies showed that ALP activity was competitively inhibited by 0.67 mM sodium hydrogen orthophosphate (NaH2PO4) and the inhibition constant (Ki) was 0.9x10-3 M. The optimum pH value for ALP activity was about 9.2 and optimum temperature registered 45°C. ALP activity exhibited linear Arrhenius relationship at temperature greater than 44.95°C with corresponding catalytic energy of activation (Ea) = 15.23 KJ mole-1. The present study gave insights into characteristic catalytic properties of ALP extracted from L. townsendii liver.