Abstract
Viable cells of Saccharomyces cerevisiae 4484-24D-1 mutant strain were treated with an Arthrobacter sp. β-1, 3-glucanase, Zymolyase-60, 000, in the presence of a serine protease inhibitor, phenylmethylsulfonyl fluoride. Fractionation of the solubilized materials with Cetavlon (cetyltrimethylammonium bromide) yielded a purified mannan-protein complex, which had a molecular weight of ca. 150, 000, approximately three times higher than that of the mannan isolated from the same cells by the hot-water extraction method at 135C. The amino acid composition of the mannan-protein complex was found to be very similar to that of the mannan-protein complexes of S. cerevisiae X2180-1A wild and S. cerevisiae X2180-1A-5 mutant strains, indicating the presence of large amounts of serine and threonine. It was unexpected that the antibody-precipitating activity of this complex against the homologous anti-whole cell serum was about twice as great as that of the mannan isolated by hot-water extraction. Treatment of this complex with 100mM NaOH, hot water at 135C, and pronase, respectively, gave degradation products having the same molecular weight and antibody-precipitating activity as those of the hot-water extracted mannan, allowing the assumption that the protein moiety participated in a large part of this activity.
