Studies on the yeast cell wall mutants.

用N-甲基-N ′-硝基-N-亚硝基胍对酿酒酵母X2180-1A进行诱变，获得了酵母细胞壁突变株。酿酒酵母突变体表现出相当大的形态变化和消化率的溶解酶。对突变体和野生型细胞的蛋白质和碳水化合物的连续提取表明，突变体具有较高的蛋白质提取率，缺乏一些壁蛋白和碳水化合物组分，并对突变体细胞壁甘露聚糖和β-葡聚糖的化学结构<beta>进行了研究。对突变甘露聚糖的结构分析表明，N3和N3-8突变甘露聚糖都缺乏-1，2-甘露糖基侧链。突变细胞的碱溶性<beta>葡聚糖的结构也不同于野生型细胞的1，6-键与1，3-键的比例。突变葡聚糖具有高得多的<beta>-1，6-键与1，3-键的比率。

Yeast cell wall mutants were obtained by mutagenesis of Saccharomyces cerevisiae X2180-1A, a haploid strain, with N-methyl-N'-nitro-N-nitrosoguanidine.The two S. cerevisiae mutants showed considerable morphological changes and digestibilities to lytic enzymes. Sequential extractions of proteins and carbohydrates from the mutant and wild type cells indicate that the mutants have high protein extractability and lack some wall proteins as well as carbohydrate components.Chemical structures of cell wall mannans and <beta>-glucans from the mutants were studied. Structural analysis of mutant mannans indicated that both N3 and N3-8 mutant mannans lacked-1,2-mannosyl side chains. Structures of alkali-soluble <beta>-glucans from the mutant cells were also different from that of wild type cells in the ratio of 1,6-linkages to 1,3-linkages. The mutant glucans have much higher ratios of <beta>-1,6-linkages to 1,3-linkages.