title: The cytochrome complement of Haemophilus parasuis.
abstract: Spectral analyses with subcellular fractions derived from Haemophilus parasuis demonstrated that this organism could synthesize membrane-bound and soluble CO- and NO-binding c-type cytochromes in addition to the membrane-bound cytochromes d, a1, b, and c; cytochromes d, a1, and o were identified as potential oxidases. The membrane-bound and soluble CO- and NO-binding cytochromes c were not spectrally variant cytochromes c, and the redox properties of the soluble cytochrome (reducible by NADH but not by succinate or ascorbate plus N,N,N',N'-tetramethyl-p-phenylenediamine) suggested that it, at least, was a low-potential cytochrome; up to 68% of the soluble cytochrome c could be released from the organisms by osmotic-shock treatment, demonstrating its extracytoplasmic location. The cytochrome content of H. parasuis was influenced by both the composition of the growth medium and the phase of growth; it is suggested that the bacterial concentration and growth rate, and therefore the availability of oxygen, regulated cytochrome synthesis.
mesh_terms: D001205:Ascorbic Acid / Q000378:metabolism; D002248:Carbon Monoxide / Q000378:metabolism; D003470:Culture Media; D003580:Cytochromes / Q000378:metabolism*; D006190:Haemophilus / Q000201:enzymology* / Q000254:growth & development; D008024:Ligands; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D009537:Nicotinamide Mononucleotide / Q000378:metabolism; D009997:Osmotic Pressure; D010101:Oxygen Consumption; D013053:Spectrophotometry; D013386:Succinates / Q000378:metabolism; D019802:Succinic Acid; D013772:Tetramethylphenylenediamine / Q000378:metabolism
chemical_list: D003470:Culture Media; D003580:Cytochromes; D008024:Ligands; D013386:Succinates; D009243:NAD; D009537:Nicotinamide Mononucleotide; D009249:NADP; D002248:Carbon Monoxide; D019802:Succinic Acid; D013772:Tetramethylphenylenediamine; D001205:Ascorbic Acid