Transient Accumulation of Heme O (Cytochrome o) in the Cytoplasmic Membrane of Semi-anaerobic Anacystis nidulans EVIDENCE FOR OXYGENASE-CATALYZED HEME O/A TRANSFORMATION

摘要: Abstract Incubation of obligately photoautotrophic and aerobic cyanobacterium Anacystis nidulans (Synechococcus sp. PCC 6301) in the light presence photosystem II inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea equilibrated with approximately 1% (v/v) O2 N (10 μM solution) led to a decrease heme A content isolated cytoplasmic membranes appearance O. The latter was not seen from fully aerated cells (>210 dissolved O). Non-covalently bound hemes extracted were identified by reversed phase high performance liquid chromatography. Heme O contents changed reversible fashion solely depending on ambient oxygen regime. Both combine same apoprotein as suggested immunoblotting. CO/reduced-minus-reduced optical difference spectra, photoaction spectra CO-inhibited uptake membranes, pyridine hemochrome pointed either belonging functional form terminal oxidase. NADH:O oxidoreductase reaction catalyzed both low strictly dependent addition catalytic amounts cytochrome c, inhibited 1.2 KCN, insensitive 5 2-n-heptyl-4-hydroxyquinoline-N-oxide. effectively N,N,N‘,N‘-tetramethyl-p-phenylenediamine but 2-methylnaphthoquinol or plastoquinol-1 artificial substrates. Therefore we conclude that cyanobacterial respiratory oxidase, irrespective type its O2-reducing center, is c rather than quinol