Biosynthesis of beta-glucans by cell-free extracts from Saccharomyces cerevisiae.
Cell-free extracts from Saccharomyces cerevisiae catalyzed the incorporation of glucosyl residues from UDP-[U-14C]glucose into beta-1,3-glucans which contained a significant proportion of beta-1,6-glycosidic linkages. When GDP-[U-14C]glucose was used as substrate only trace amounts of glucose were incorporated. Activity of beta-glucan synthetase was distributed among membrane and cell wall fractions, specific activity being higher in this latter. Beta-glucan synthesized by membrane and cell wall fractions contained 0.6% and 2.5% of beta-1,6-glycosidic linkages respectively. A marked decrease in the activity of beta-glucan synthetase occurred as the cells aged. Significant activity of glycogen synthetase was detected only in cells which had reached the stationary phase of growth.
D002453:Cell Cycle; D002474:Cell-Free System; D005964:Glucosyltransferases / Q000378:metabolism; D006006:Glycogen Synthase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008968:Molecular Conformation; D011134:Polysaccharides / Q000096:biosynthesis*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D012995:Solubility; D013347:Subcellular Fractions / Q000201:enzymology
D011134:Polysaccharides; D005964:Glucosyltransferases; D006006:Glycogen Synthase