Membrane-bound cytochromes in a sulfate-reducing strict anaerobe Desulfovibrio vulgaris Miyazaki F.
Cytoplasmic membranes were isolated from the cells of a sulfate-reducing strict anaerobe Desulfovibrio vulgaris Miyazaki F and membrane-bound cytochromes were characterized. Redox difference spectra at 77 K revealed the presence of cytochromes with the alpha peaks at 552 and 556 nm while CO-binding difference spectra showed the presence of o-type cytochrome(s). Partial purification of the cytochromes demonstrated that the membranes contain cytochromes c550, c551, c556 and possibly d1 besides high molecular mass cytochrome c and cytochrome c3. It turned out that two kinds of novel CO-binding c-type cytochromes are present in the membrane. The membranes and a partially purified fraction showed weak ubiquinol-1 oxidase activity but no cytochrome c oxidase activity. Results suggest that D. vulgaris does not express the heme-copper terminal oxidase under our growth conditions in spite of the presence of the col gene, which is homologous to the gene of subunit I of the aa3-type oxidase.
Ozawa
K
K
Department of Bioengineering, Faculty of Engineering, Yokohama National University, Hodogaya-ku, Yokohama, 240, Japan.
Mogi
T
T
Suzuki
M
M
Kitamura
M
M
Nakaya
T
T
Anraku
Y
Y
Akutsu
H
H