Hederstedt L
J Bacteriol. 1980 Dec;144(3):933-40. doi: 10.1128/jb.144.3.933-940.1980.
In previous work with membranes of Bacillus subtilis, the succinate dehydrogenase complex was isolated by immunoprecipitation of Triton X-100-solubilized membranes. The complex included a polypeptide with an apparent molecular weight of 19,000, probably attributable to apocytochrome. This paper reports the further characterization of this cytochrome and its relation to the respiratory chain of B. subtilis. The cytochrome was identified as cytochrome b, and its difference absorption spectra showed maxima at 426, 529, and 558 nm at room temperature. The oxidized cytochrome had an absorption maximum at 413 nm. The cytochrome was reduced by succinate in the isolated succinate dehydrogenase complex and in Triton X-100-solubilized membranes. In whole membranes cytochromes b, c, and a were reduced by succinate. In membranes from a mutant containing normal cytochromes but lacking succinate dehydrogenase no reduction of cytochrome was seen with succinate. It was concluded that the isolated succinate dehydrogenase-cytochrome b complex is a functional unit in the intact B. subtilis membrane. An accompanying paper describes cytochrome b as a structural unit involved in the membrane binding of succinate dehydrogenase.
在之前对枯草芽孢杆菌膜的研究工作中，通过对经 Triton X - 100 增溶的膜进行免疫沉淀来分离琥珀酸脱氢酶复合体。该复合体包含一种表观分子量为 19,000 的多肽，可能归因于脱辅基细胞色素。本文报道了这种细胞色素的进一步特性及其与枯草芽孢杆菌呼吸链的关系。该细胞色素被鉴定为细胞色素 b，其差示吸收光谱在室温下于 426、529 和 558 nm 处有最大值。氧化型细胞色素在 413 nm 处有最大吸收峰。在分离出的琥珀酸脱氢酶复合体以及经 Triton X - 100 增溶的膜中，该细胞色素可被琥珀酸还原。在完整的膜中，细胞色素 b、c 和 a 可被琥珀酸还原。在来自一个含有正常细胞色素但缺乏琥珀酸脱氢酶的突变体的膜中，未观察到琥珀酸对细胞色素的还原作用。得出的结论是，分离出的琥珀酸脱氢酶 - 细胞色素 b 复合体是完整的枯草芽孢杆菌膜中的一个功能单元。一篇附带的论文将细胞色素 b 描述为参与琥珀酸脱氢酶膜结合的一个结构单元。
