A Study of Saccharomyces cerevisiae Cell Wall Glucans

Much research has been carried out over the years examining cell wall glucans from Saccharomyces cerevisiae and this study further examines aspects of the binding of (1r4)-α-D-glucan in the yeast cell wall, using a number of isolation techniques as well as monoclonal antibodies able to recognize a mixed (1r4)-α-D-glucan/(1r6)-β-D-glucan. Extraction of purified glucan, from S. cerevisiae cell wall, with 0.1N HCl, at 80°C for 6 h, released into the solution (1r4)-α-D-glucan and (1r6)-β-D-glucan as the major polysaccharides, along with an insoluble pellet highly enriched in (1r3)-β-D-glucan. The released (1r4)-α-D-glucan was composed of a high molecular size >100 kDa fraction (7.2% w/w) and a medium 5–50 kDa polysaccharide (10.2% w/w), with the (1r4)-α-D-glucan covalently bound to the (1r6)-β-D-glucan. The average molar ratio of the α:β glucan was 47: 53 in this mixed polysaccharide. The structure of this polysaccharide was different from the structure of plant starch or animal glycogen as monoclonal antibodies specific to yeast (1r4)-α-D-glucan/(1r6)-β-D-glucan did not recognize the plant starch or animal glycogen standards.