Glucose associated repression

Babczinski and Tanner,S3 have reported an additional isoenzyme of /3-D-fructofuranosidase which they considered to be a precursor of the main enzyme. This new enzyme is associated with crude, membrane fractions of the cells it has a molecular weight of 190,000, and appears transiently, as < 5% of the total /3-D-fructofuranosidase, when the yeast is actively synthesizing the external enzyme. From studies on the effects of D-glucose repression and of cycloheximide, Sentandreu and coworkers (see Ref. 154) also considered that such an enzyme, associated more with internal membranes than with plasmalemma, might be, at least in part, a precursor of the external /3-D-fructofuranosidase in the process of secretion. 

Catabolite repression. The general repression of transcription of genes associated with catabolism that is seen in the presence of glucose. 

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