枯草芽孢杆菌中葡萄糖代谢的研究。I. 从营养细胞中纯化6-磷酸葡萄糖脱氢酶及其与芽孢酶性质的比较。

Studies of glucose metabolism in Bacillus subtilis. I. Purification of glucose-6-phosphate dehydrogenase from the vegetative cell and its properties in comparison with the spore enzyme.

Ujita S, Kimura K

J Biochem. 1975 Jan 1;77(1?):197-206.

Abstract

Glucose-6-phosphate dehydrogenase [D-glucose-6-phosphate : NADP-+ 1-oxidoreductase, EC 1.1.1.49] from vegetative cells of Bacillus subtilis was purified about 2,400-fold. The purified enzyme was shown to be homogeneous as judged by chromatographic profile, polyacrylamide gel electrophoresis and ultracentrifugation. The correspondent enzyme from spores was also partially purified. 2. The molecular weight of the vegetative cell enzyme was estimated to be 350,000 by Sepharose 6B chromatography and sedimentation equilibrium studies, and that of its subunit was 58,000 as determined by SDS gel electrophoresis, indicating that the enzyme was found to be 240,000. 3. The vegetative cell enzyme and spore enzyme have the same Km values and pH optima. The optimum pH was about 9.2 for both enzymes and the Km values for NADP-+ and glucose-6-phosphate were determined to be 6.7 X 10-minus 6 and 7.5 X 10-minus 5M, respectively. 4. The amino acid composition of the vegetative cell enzyme was examined and was compared with those of enzymes from other sources.

摘要

对枯草芽孢杆菌营养细胞中的葡萄糖-6-磷酸脱氢酶[D-葡萄糖-6-磷酸：NADP⁺ 1-氧化还原酶，EC 1.1.1.49]进行了约2400倍的纯化。通过色谱图谱、聚丙烯酰胺凝胶电泳和超速离心判断，纯化后的酶显示为均一的。来自芽孢的相应酶也进行了部分纯化。2. 通过琼脂糖6B色谱和沉降平衡研究，营养细胞酶的分子量估计为350,000，通过SDS凝胶电泳测定其亚基分子量为58,000，这表明该酶由六个亚基组成。3. 营养细胞酶和芽孢酶具有相同的Km值和最适pH。两种酶的最适pH约为9.2，NADP⁺和葡萄糖-6-磷酸的Km值分别测定为6.7×10⁻⁶和7.5×10⁻⁵M。4. 对营养细胞酶的氨基酸组成进行了检测，并与其他来源的酶进行了比较。