Marchin G L, Duerksen J D
J Bacteriol. 1968 Oct;96(4):1181-6. doi: 10.1128/jb.96.4.1181-1186.1968.
Saccharomyces lactis strain Y-123, a constitutive high producer of beta-glucosidase (B(h)), was grown in an enriched medium. beta-Glucosidase, extracted most easily by cell autolysis, was purified by successive ammonium sulfate precipitation, ethyl alcohol precipitation, gel filtration, calcium phosphate gel adsorption-elution, and hydroxyapatite column chromatography. The specific activity of the enzyme increased 200-fold during the purification. The electrophoretic and catalytic properties of the enzyme did not change during the procedure. Polyacrylamide gel disc electrophoresis of the partially purified enzyme revealed one major and several minor protein-staining bands. beta-Glucosidase activity in the polyacrylamide gel columns was measured directly by assaying sections of columns frozen and sliced immediately after electrophoresis. Most of the activity coincided with the major protein-staining band. Prolonged assay produced minor activity coinciding with the less intense protein bands. Properties of the enzyme suggest that it is a single, unconjugated, intracellular, high molecular weight protein. The purification procedure is applicable to strains of S. lactis which possess alleles of the B locus for beta-glucosidase synthesis.
乳酸酵母菌株Y - 123是一种组成型β - 葡萄糖苷酶高产菌株（B(h)），在富集培养基中培养。β - 葡萄糖苷酶最容易通过细胞自溶提取，经连续硫酸铵沉淀、乙醇沉淀、凝胶过滤、磷酸钙凝胶吸附 - 洗脱和羟基磷灰石柱色谱法纯化。在纯化过程中，该酶的比活性增加了200倍。在此过程中，酶的电泳和催化特性未发生变化。对部分纯化的酶进行聚丙烯酰胺凝胶圆盘电泳，显示出一条主要的和几条次要的蛋白质染色带。聚丙烯酰胺凝胶柱中的β - 葡萄糖苷酶活性通过对电泳后立即冷冻切片的柱段进行测定来直接测量。大部分活性与主要蛋白质染色带一致。长时间测定产生与较弱蛋白质带一致的次要活性。该酶的特性表明它是一种单一的、未结合的、细胞内的高分子量蛋白质。该纯化程序适用于具有β - 葡萄糖苷酶合成B位点等位基因的乳酸酵母菌株。
