Random Attack as the Hydrolytic Reaction Mode of Oligosaccharides byRhizopusGlucoamylase

Abstract

Hydrolytic reactions of maltooligosaccharides (degree of polymerization n = 3–7) and isomaltooligosaccharides (n = 3–7) by Rhizopus glucoamylase (at pH 4.5, 25°C) were observed by HPLC. It was confirmed that initial rates of the decrease of n-mer substrate and the increase of the products, glucose and (n – 1 )-mer oligosaccharide, are the same for all the substrates, indicating that the reaction mode of the enzyme is “random attack,” and no “multiple attack” or “single chain attack” is operating.