Fungal Cellulases XIII. Specificity of the Induction of the ?-Glucosidase of Stachybotrys Atra

Abstract

Only J3-g1ucopyranosides, J3-thioglucopyranosides, and certain J3-g1ucopyrano-sides substituted by glycosyl residues are effective as inducers of aryl J3-glucosidase in S. atra. All other modifications of structure give molecules ineffective as inducers. The induction of aryl J3-g1ucosidase and cellobiase appear to be independent processes; polyhydroxylic alkyl J3-g1ucosides become less effective inducers of aryl J3-g1ucosidase and more effective inducers of cellobiase as the chain-length of the aglycone increases. The interaction between inducer and the enzyme-synthesizing system follows Michaelis-Menten kinetics with each inducer having a characteristic affinity for the "active centre". This relationship holds whether rate of enzyme synthesis or total amount synthesized is considered, since the length of the period of active enzyme synthesis appears to be independent of inducer concentration.