Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by phenylglyoxal

The kinetics method of the substrate reaction during modification of enzyme activity previously described by Tsou (Adv. Enzymol. Related. Areas Mol. Biol., 1988, 61, 381-436) has been applied to study the kinetics of the course of inactivation of green crab alkaline phosphatase by phenylglyoxal. The obtained results shows that the inactivation of the enzyme by phenylglyoxal is a slow reversible reaction. The microscopic rate constants for the reaction of the inhibitor with the enzyme were determined. The presence of substrate offers marked protection of this enzyme against inactivation by phenylglyoxal. The above results suggest that the arginine residue is essential for activity and is situated at the active site of the enzyme.