Measurement of Plasma Amylase Activity

ACTION OF AMYLASE a-Amylase (1,4-a-D-glucan glucanohydrolase, EC 3.2.1.1) is an endoglycosidase that catalyses t~e rand~m endohydrolysis of I, 4-a-glucosidic linkages In starch, glycogen and other glucose polymers. 1, 6-a-linkages are not hydrolysed. Amylose, the linear glucose polymer compo~ent of starch containing only I, 4-a-glucosidic linkages, yields maltose, maltotriose and some glucose. Amylopectin, the branched compon~n~ of starch, yields these and products cont~I~Ing u~hydrolysed 1, 6-a-linkages called limit dextnns. Most starches contain 20-28% amylose and 72-80% amylopectin. Amylase hydrolyses amylopectin significantly faster than amylose. a-Amylase is a calcium-requiring metalloenzyme with at least one calcium atom tightly bound per protein molecule. The presence of thi~ .calcium is required for full enzymatic activity and stability of enzyme. I. 2 Chloride is an allosteric activator of amylase and is required at a concentration of not less than 10 rnrnol/L for optimal activity.:' The optimal pH for amylase activity is around neutrality, pH 7, but can shift in the absence of chloride."