期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：1
页码：147-151
DOI：10.1073/pnas.77.1.147
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：From the plasma membrane of Thermus thermophilus HB8 we have partially purified a detergent-solubilized complex of cytochromes a and c1 that actively catalyzes the transfer of electrons from ascorbate via a redox dye to oxygen. The complex is composed of two types of polypeptides, with molecular weights of approximately 55,000 and 33,000. Quantitative analysis revealed the presence of heme a, heme c, and copper in a ratio of 2:1:2, with the heme a being present at 10 +/- 1.3 nmol/mg of protein. The heme c was shown to be associated with the molecular weight 33,000 peptide and is suggested to be of the c1 type. The optical and electron paramagnetic resonance properties of this complex were found to be similar to those of eukaryotic cytochrome oxidase, suggesting the following arrangement of chromophores: a magnetically isolated cytochrome c1 and an oxygen-reducing functional unit consisting of two heme a groups and two copper ions associated with one or more larger peptides.
