Abstract
Alkaline phosphatase from the excretory system of the grasshopper, Poekilocerus bufonius was purified with ammonium sulphate fractionation and chromatography on Bio-Gel A-0.5 m. The specific activity of the enzyme is 152 units/mg of protein. The enzyme is a tetramer and the M sub(r) value of the subunit is 72,000 plus or minus 2500 as shown by gel filtration and SDS-polyacrylamide gel electrophoresis. The enzyme has a pH optimum of 9.6 an apparent K sub(m) value of 0.28 x 10 super(-3) M. The activity of the enzyme reached a maximum at 75 degree C and the enzyme showed stability at 65 degree C. The enzyme was inhibited by Ca super(2+), Na super(+) and Fe super(3+) and was stimulated by Zn super(2+), Mn super(2+) and Mg super(2+).