Nishihara H, Toraya T, Fukui S
Arch Microbiol. 1977 Oct 24;115(1):19-23. doi: 10.1007/BF00427840.
Effects of treatments with proteolytic enzymes and protein-modifying reagents on flocculation of brewer's yeast IFO 2018 were investigated. The floc-forming ability of the yeast cells was irreversibly eliminated by treatment with papain, trypsin, chymotrypsin or pepsin, indicating that certain proteins on the cell surface participate in the yeast flocculation. Chemical modification with reagents, known to act on disulfide bridges, carboxyl and/or phosphate groups, phenolic groups, amino groups, and imidazole groups, also destroyed the ability to flocculate, although in some cases a high concentration (8 M) of urea was necessary in addition to protein-modifying reagents. Thus, it is suggested strongly that these functional groups of amino acid residues of the proteins are essential for the floc-forming ability of brewer's yeast cells.
研究了用蛋白水解酶和蛋白质修饰试剂处理对啤酒酵母IFO 2018絮凝的影响。用木瓜蛋白酶、胰蛋白酶、胰凝乳蛋白酶或胃蛋白酶处理可不可逆地消除酵母细胞的絮凝形成能力，这表明细胞表面的某些蛋白质参与了酵母絮凝。用已知作用于二硫键、羧基和/或磷酸基团、酚羟基、氨基和咪唑基团的试剂进行化学修饰，也会破坏絮凝能力，尽管在某些情况下除了蛋白质修饰试剂外还需要高浓度（8M）的尿素。因此，强烈表明蛋白质氨基酸残基的这些官能团对于啤酒酵母细胞的絮凝形成能力至关重要。
