Acid phosphatase from snail heamolymph: a cheap and convenient source of enzyme for kinetic parameters determination

The study of enzymes occupies a very important position in biological, medical and industrial research. Also, the satisfactory performance of an enzyme assay provides a good introduction to biochemical techniques. This experiment presents a good introductory project to students for the estimation of the kinetic parameters of an enzyme. The spectrophotometric/colorimetric assay of acid phosphatase is very simple with a readily available substrate, p-nitrophenyl phosphate, which can easily be purchased, and other common laboratory reagents; sodium hydroxide, sodium acetate and ethylenediamine-tetraacetic acid (EDTA). The snail is cheap and the heamolymph collected required no hemolysis and/or centrifugation. The assay method does not require an additional reagent for colour development. Earlier acid phosphatase had been found to be present in a relatively high activity in the heamolymph of the giant African snail, Archachatina marginata, and is highly specific for p-nitrophenyl phosphate.   Key words: Acid phosphatase, snail, Archachatina marginata, heamolymph, p-nitrophenyl phosphate.