Studies on the yeast cell wall mutants.

以单倍体酿酒酵母X2180-1A为出发菌株，经N-甲基-N‘-硝基-N-亚硝基-N-亚硝基诱变获得酵母细胞壁突变体，两株突变体均表现出明显的形态变化和对裂解酶的消化能力。从突变体和野生型细胞中连续提取蛋白质和碳水化合物表明，突变体具有较高的蛋白质萃取率，缺乏一些壁蛋白和糖类成分。对突变体的细胞壁甘露聚糖和β-葡聚糖的化学结构进行了研究。突变甘露聚糖的结构分析表明，N3和N3-8突变甘露聚糖均缺乏-1，2-甘露糖基侧链。突变细胞碱溶β-葡聚糖的1，6-键与1，3-键的比例也与野生型细胞不同。突变的葡聚糖具有更高的β-1，6-键与1，3-键的比例。

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.