Abstract
By using the authentic anomers of D-glucopyranose under conditions limiting mutarotation, it was found that the condensation reactions catalyzed by glucoamylase require a donor substrate of specific configuration. A highly purified glucoamylase from Trichoderma viride, which hydrolyzes amylaceous substrates to β-D-glucopyranose, was found to catalyze the rapid synthesis of maltose and isomaltose specifically from p-n-glucopyranose. The configurational inversion accompanying the condensations indicates that the D-glucopyranosyl portion of a-D-glucopyranose is interchanged with hydrogen at the C4 or C6 carbinol site of a second n-glucose molecule (glucosyl transfer).
