Kinetics of human pancreatic and salivary α-amylases with carboxymethylamyloses as substrates

Abstract

The enzymatic measurement of α-amylase in human serum with chemically modified amylose as substrate was studied. Several substitutions of carboxymethylamylose were prepared from amylose, suitable amounts of monochloroacetic acid, and sodium hydroxide. The relationship between the degree of substitution of the Carboxymethylamylose and the kinetic parameters of human pancreatic, salivary and porcine pancreatic α-amylases was determined. The action of α-amylases on such modified amyloses in the presence of glucoamylase was measured by a specific enzymatic assay having glucose as the product. The kinetic parameters of human pancreatic α-amylase were similar to those of human salivary α-amylase. It was possible to determine suitable sensitivities for the α-amylase assay using this substrate. These results suggested a subsite model.