title: Characterization of the electron transport system in Brucella abortus.
abstract: The electron transport system in Brucella abortus has been characterized. Spectral studies of membrane preparations have indicated the presence of cytochromes a + a3 (maxima at 612 nm), cytochrome b (maxima at 560, 530, and 428 nm), cytochrome c (maxima at 552 and 522 nm), cytochrome o (maxima of carbon monoxide complex at 418 nm), and flavoproteins (minimum at 582 and 450 nm). Cytochromes a + a3 appeared only after cells had reached late log phase, possibly due to lowered oxygen tension in the medium. Dehydrogenases were shown to be present for D-erythritol 1-phosphate, L-lactate, reduced nicotinamide adenine dinucleotide, and succinate. All of the above substrates reduced the electron transport chain and at least some of the flavoproteins, indicating similar pathways of electron transport. N-ethylmaleimide, p-chloromercuribenzoate, and KCN were the only electron transport inhibitors that blocked electron transport by 100%. The system seemed to be uniquely resistant to other electron transport inhibitors.
mesh_terms: D001205:Ascorbic Acid / Q000378:metabolism; D002003:Brucella abortus / Q000201:enzymology / Q000378:metabolism*; D002458:Cell Fractionation; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D002729:Chloromercuribenzoates / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D003580:Cytochromes / Q000378:metabolism; D004579:Electron Transport / Q000187:drug effects; D004896:Erythritol; D005033:Ethylmaleimide / Q000494:pharmacology; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D005420:Flavoproteins / Q000378:metabolism; D007773:Lactates / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D010101:Oxygen Consumption; D011048:Polarography; D013053:Spectrophotometry; D013386:Succinates / Q000378:metabolism; D013403:Sugar Phosphates / Q000378:metabolism
chemical_list: D002729:Chloromercuribenzoates; D003486:Cyanides; D003574:Cytochrome c Group; D003580:Cytochromes; D005420:Flavoproteins; D007773:Lactates; D013386:Succinates; D013403:Sugar Phosphates; D009243:NAD; D005182:Flavin-Adenine Dinucleotide; D009249:NADP; D010088:Oxidoreductases; D005033:Ethylmaleimide; D001205:Ascorbic Acid; D004896:Erythritol