DIFFERENTIATION OF 2 TREHALASE ACTIVITIES PRESENT IN SACCHAROMYCES-CEREVISIAE BY COPPER

Presence of two different trehalases in response to their interaction with Cu2+ has been demonstrated in Saccharomyces cerevisiae. Treahalas e, extracted from vegetative cells, is found to be inhibited by the pr esence of Cu2+ (2 mM) while the other extracted from germinating tells is activated by the same. Increase in trehalase activity together wit h increase in intracellular c-AMP and glucose level has been noticed a t the onset of spore germination. Optimum trehalase activity (germinat ing) is noticed at pH 5.0, temperature 35 degrees and in presence of 2 mM Cu2+. The enzyme has relatively low K-m (0.385 mM). The results su ggest that it is an acid trehalase (non-regulatory trehalase), Enzyme solution containing Cu2+ (2 mM) is found to be more stable against exp osures to various temperatures and pHs in comparison to enzyme solutio n without Cu2+. So the role of Cu2+ appears to be providing stability to the trehalase molecule.