The homology of Pseudomonas cytochrome c-551 with eukaryotic cytochromes c is examined with a computer-based procedure devised to determine whether similarities exist between these proteins. One method is given by which the more recently evolved cytochromes c might have arisen from the Pseudomonas protein. This procedure involves only common genetic phenomena and accounts for most of the struct...

The midpoint potentials of the mitochondrial respiratory chain cytochromes of the protozoan Crithidia fasciculata at pH 7.2, Em7.2, show great similarity to those measured in higher organisms. Values of Em7.2 for cytochromes a and a3 are +165 and +340 mV. Both c cytochromes have Em7.2 = +230 mV. There are two b cytochromes with the same spectral characteristics with Em7.2 = -20 and -135 mV. The...

1. A modified method for the separation and purification of four cytochromes c from Azotobacter vinelandii is described. Two new cytochromes c have been purified and are designated cytochromes c(551) and c(555). 2. Additional evidence is presented to establish the dihaem nature of cytochrome c(4). Ultracentrifugation data indicated similar molecular weights for the native and the denatured prot...

Cytochrome c(1) from mitochondrial complex III and the di-heme cytochromes c in the corresponding enzyme from epsilon-proteobacteria have so far been considered to represent unrelated cytochromes. A missing link protein discovered in the genome of the hyperthermophilic bacterium Aquifex aeolicus, however, provides evidence for a close evolutionary relationship between these two cytochromes. The...

Voltammetric studies of c-type cytochromes at clay-modified pyrolytic graphite electrodes have been undertaken as providing a good model for investigating interactions of proteins with soils. Different clays have been investigated according to their global charge, composition and hydrophobicity. The electrochemical behavior of either mitochondrial or bacterial cytochromes at these modified elec...

Methanosarcina strain Gö1 was tested for the presence of cytochromes. Low-temperature spectroscopy, hemochrome derivative spectroscopy, and redox titration revealed the presence of two b-type (b559 and b564) and two c-type (c547 and c552) cytochromes in membranes from Methanosarcina strain Gö1. The midpoint potentials determined were Em,7 = -135 +/- 5 and -240 +/- 11 mV (b-type cytochromes) and...

HE cytoplasmic factor ( p ) and many nonallelic chromosomal genes determine the presence of cytochromes in yeast (EPHRUSSI 1953; GUNGE 1966; SHERMAN 1963). Ordinarily, a respiration-deficient (RD) mutant defective in any of these determinants lacks cytochromes a and b, but possesses cytochrome c at a normal or increased level, when grown aerobically. Recently, some mutant yeasts have been repor...

In a preliminary communication (Trudinger, 1958) the separation of some soluble cytochromes of the autotrophic sulphur bacterium Thiobacillue X was briefly reported. Addition of thiosulphate to intact cells results in the rapid reduction of the cytochromes and the present work was undertaken to attempt to characterize the cytochromes and to obtain some information on the electron-transport chai...

Confocal Resonance Raman Microscopy (CRRM) was used to probe variations of redox state of c-type cytochromes embedded in living mixed-culture electroactive biofilms exposed to different electrode polarizations, under potentiostatic and potentiodynamic conditions. In the absence of the metabolic substrate acetate, the redox state of cytochromes followed the application of reducing and oxidizing ...

Antibodies against cytochromes P-450a, P-450b + P450e, P-450c, and P-450d and epoxide hydrolase were utilized in a radial immunodiffusion assay to measure the concentration of these inducible, xenobiotic-metabolizing enzymes in liver microsomes from rats treated with Aroclor 1254, fireMaster BP-6, or one of 41 individual polychlorinated and polybrominated biphenyl isomers and congeners. Cy...