The influence of structure on the hydrolysis of substituted phenyl α- d -glucosides by α-glucosidase

Nath & The present paper describes a similar study of the hydrolysis of some substituted phenyl OC-D-glucosides by the a-glucosidase of brewer's yeast. A kinetic investigation of ac-gluco- sidase was carried out by Jsaiev (1926), who studied the hydrolysis of maltose by this enzyme and concluded that Michaelis-Menten kinetics were not strictly obeyed. However, Halvorson & Elias (1958) found that such kinetics were followed in the hydrolysis of p-nitrophenyl Oc-D-glucoside by the oc-glucosidase of Saccharomyces italicus (K, = 0-28 mM). The justification for our use of the Michaelis-Menten theory in interpreting our experimental results is discussed below. Substituted phenyl OC-D-glucosides are much more diffi- cult to prepare in a state of purity than their fanomers, and for this reason the present work has involved only 10 substrates, as compared with the 21 studied by Nath &