Quantitative Determination of Anomeric Forms of Sugar Produced by Amylases

Abstract

The anomer form of product maltose formed in the hydrolytic reaction of phenyl α-maltoside into phenol and maltose catalyzed by crystalline saccharifying α-amylase [EC 3.2.1.1] from Bacillus subtilis was determined quantitatively under the condition that the alternative pathway (hydrolysis into glucose and phenyl α-glucoside (1)) could be ignored. The procedure involved continuous measurements of optical rotation change and of simultaneous phenol production during the reaction, which was carried out at 24.7°C, pH 5.4 and at 0.478 mM substrate concentration. It was quantitatively demonstrated that maltose released from phenyl α-maltoside was exclusively of α-form, indicating that the configuration of the substrate linkage between glucose and phenyl residues was retained during the hydrolysis catalyzed by this enzyme.