Yeast insoluble polysaccharide

Yeast Insoluble Polysaccharide. The structure of an insoluble polysaccharide from the yeast Saccharomyces cerevisiae was investigated by Zechmeister and Toth,90a and also by Hassid, Joslyn and McCready.904 The isolation904 of 2,4,6-trimethyl-D-glucose as the sole product of the hydrolysis of the methylated polysaccharide indicated a chain of gluco-pyranose units joined by 1,3-glucosidic linkages. 

Yeast Insoluble Polysaccharide.—The skeletal polysaccharide of yeast has been shown to be a polyglucose in which the residues are joined by 1,3-glycosidic linkages.119 An indication that the molecular weight was of the order of 8,000 (36 units) was obtained from the specific viscosity, and a closed-chain type of structure for the molecule was suggested as no end-groups were found in the methylation studies. 

Yeast insoluble-polysaccharide Methyl ether Viscosity m-Cresol 8,000( ) 36 — Closed chain 59... 

Dextrans are bacterial and yeast polysaccharides made up of (a 1—>6)-linked poly-D-glucose all have (al—>3) branches, and some also have (al—>2) or (al—>4) branches. Dental plaque, formed by bacteria growing on the surface of teeth, is rich in dextrans. Synthetic dextrans are used in several commercial products (for example, Sephadex) that serve in the fractionation of proteins by size-exclusion chromatography (see Fig. 3-18b). The dextrans in these products are chemically cross-linked to form insoluble materials of various porosities, admitting macromolecules of various sizes. 

Maltase accompanies amylase in animal tissues and completes the hydrolysis of polysaccharides. It is present in many bacteria, fungi, and yeasts, and in an insoluble form in ungerminated cereals. The optimal range of activity is about pH 6T (intestinal maltase) to pH 4-1 (malt-extract maltase). 

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