The beta-glucosidase of the yeast cell surface.

摘要: There are two distinct components of the system which limits rate at intact cells S. cerevisiae C hydrolyze external s-glucosides; one component requires metabolic energy and other is stereospecific for s-glucosides. The localized cell membrane, as shown by its sensitivity to heavy metal inhibitors did not penetrate under conditions used. It was that cellobiose-grown were able remove cellobiose from medium in they incubated, uptake identical patent s-glucosidase activity. In order test hypothesis question a transport system, s-glucosides ability take up 14C-labeled methyl-s-glucoside (MBG) studied. induced MBG-14C label could be partially chased out cold MBG cellobiose; glucose-grown incorporate label. However, when incubated with 14C-MBG, thus excluding concluded membrane actually s-glucosidase, coupled an energy-dependent glucose moiety; function latter rate-limiting over-all activity entire system.