A two-dimensional electrophoretic method which takes advantage of the "migration anomalies" experienced by some polypeptides on gels of different porosities has been successfully used to resolve the seven subunit polypeptides of yeast cytochrome c oxidase and the nine polypeptides associated with bovine cytochrome c oxidase. The two-dimensional maps provided by this method reveal clear differen...

The effects of digitonin and tocopherol on bovine heart reduced diphosphopyridine nucleotideand succinate-cytochrome c reductases and cytochrome c oxidase have been studied with the following results. 1. Low concentrations of digitonin stimulate succinateand DPNH-cytochrome c reductase and cytochrome c oxidase. Higher concentrations of digitonin completely inhibit cytochrome c reductases, while...

The extent of inhibition of cytochrome oxidase activity by cyanide depends upon the method of assay. It has been contimed that this inhibition is “readily reversible” with the use of the standard manometric technique. However, in the spectrophotometric assay only about 10% of the control activity is observed after the cyanide is removed by physical methods. The polarographic assay yields interm...

Phormidium foveolarum was grown with nitrate or ammonia as nitrogen source. With ammonia present respiration increased by a factor of 4 due to increase of cytochrome c oxidase. The inhibition of respiration by cyanide was measured during the growth period, indicating that only one terminal oxidase is present in Phormidium foveolarum . Cytochrome c oxidase from ammoniagrown filaments was solubil...

The 02, CO, and alkyl isocyanide-binding properties of a variety of vertebrate and invertebrate heme proteins have been compared in detail to those of protoheme mOn0-3-( 1-imidazoy1)-propylamide monomethyl ester in aqueous suspensions of soap micelles. The proteins examined include: cytochrome P-450,,, from Pseudomonasputida, beef heart cytochrome c oxidase, yeast cytochrome c peroxidase, a and...

The cytochrome o terminal oxidase from Escherichia coli was immunochemically purified and monospecific antiserum toward cytochrome o was obtained. This antiserum is able to precipitate 100% of the ubiquinol-1 oxidase activity in Triton X-100 extracts of membranes from an E. coli strain in which cytochrome o is the only terminal oxidase. Cytochrome o was analyzed and quantitated using crossed im...

Rotational diffusion of cytochrome oxidase in the inner membrane of rat liver mitochondria was measured by detecting the decay of absorption anisotropy after photolysis of the heme a3.CO complex by a vertically polarized laser flash. As in previous experiments with beef heart mitochondria (Kawato, S., Sigel, E., Carafoli, E., and Cherry, R. J. (1980) J. Biol. Chem. 255, 5508-5510), co-existence...

The kinetics and thermodynamics of the reaction of mixed valence state membrane-bound cytochrome oxidase with CO over the 178-203 K range has been studied by multichannel optical spectroscopy at three wavelength pairs (444-463 nm in the Soret region, and 590-630 and 608-630 nm in the alpha region) and analysed by non-linear optimization techniques. As in the case of the fully reduced membrane-b...

Three different cell types of Neurospora crussa deficient in cytochrome oxidase were studied : the nuclear mutant cni-1, the cytoplasmic mutant mi-1 and copper-depleted wild-type cells. 1. The enzyme-deficient cells have retained a functioning mitochondrial protein synthesis. It accounted for 1216 % of the total protein synthesis of the cell. However, the analysis of mitochondrial translation p...