Biochemical and Immunochemical Studies of Fungi (10)

Separation and Antigenic Activity of Glucan of Saccharomyces cerevisiae

Abstract

Acetone dried cells of Saccharomyces cerevisiae were treated with 45% phenol and further with autoclaving at 135° in water, and then the cell residue was extracted with 3% NaOH under N₂ gas at 70° for 40 minute. An alkali-soluble glucan was precipitated from the extracts in a cellophane bag which was dialyzed against running tap water. No nitrogen and phosphorus was found in the gelatinous solid glucan. On the other hand, Fehling-Cu⁺⁺ solution was added in the above mentioned hot-water extracts, and after removing mannan-Cu complex non-Cu polysaccharide (Fr I, II) was fractionated with DEAE-Sephadex column chromatography. Sugar components of the Fr I and II contained mannose and glucose, and a large quantity of glycogen was estimated in the Fr I but not in the Fr II. Fr-G resulted from dilute HOAc treatment of alkali-soluble glucan contained glucose and a trace of mannose as sugar components.
Anti-whole cells serum of S. cerevisiae which was absorbed with a complete purified mannan showed extremely weak precipitin titers (×200∼400) against these glucan fractions. Therefore, it appears that the antigenicity of glucan which located on internal wall of the whole cells may be almost neglected in case of agglutination test.