Cytochrome b was identified as one of the ubiquinone-binding proteins in bovine heart mitochondrial ubiquinol-cytochrome c reductase by photoaffinity labeling using 3-azido-2-methyl-5-methoxy-6-(3,7-dimethyl[3H]-octyl)-1,4-benzoquinone ([3H]azido-Q). The [3H]azido-Q-labeled cytochrome b protein was purified to homogeneity from the azido-Q-labeled ubiquinol-cytochrome c reductase by a procedure ...

The human HL-60 myeloid leukaemia cell line developed, during maturational changes induced by dimethyl sulphoxide, an enhanced capacity for phorbol myristate acetate- stimulated oxidative activity and acquired a cytochrome b. Titration of the absorbance at 559 nm at potentials of-190 to -370 mV indicated that this cytochrome had a very low potential, differentiating it from mitochondrial and en...

Unbiased phenotypic screens enable identification of small molecules that inhibit pathogen growth by unanticipated mechanisms. These small molecules can be used as starting points for drug discovery programs that target such mechanisms. A major challenge of the approach is the identification of the cellular targets. Here we report GNF7686, a small molecule inhibitor of Trypanosoma cruzi, the ca...

The composition and characteristics of b-type cytochromes from higher plant plasma membranes, purified using aqueous two-phase partitioning, were investigated. At least three different cytochromes were identified by their wavelength maxima and redox midpoint potentials (E(0)'). Cytochrome b-560.7 (E(0)' from + 110 to + 160 millivolts) was present in zucchini (Cucurbita pepo) hypocotyls and bean...

We demonstrate that the cccB gene, identified in the Bacillus subtilis genome sequence project, is the structural gene for a 10-kDa membrane-bound cytochrome c(551) lipoprotein described for the first time in B. subtilis. Apparently, CccB corresponds to cytochrome c(551) of the thermophilic bacterium Bacillus PS3. The heme domain of B. subtilis cytochrome c(551) is very similar to that of cytoc...

Atovaquone is a new anti-malarial agent that specifically targets the cytochrome bc1 complex and inhibits parasite respiration. A growing number of failures of this drug in the treatment of malaria have been genetically linked to point mutations in the mitochondrial cytochrome b gene. To better understand the molecular basis of atovaquone resistance in malaria, we introduced five of these mutat...

Abstract: Background: Hemiscorpius lepturus is a medically important scorpion found along the Iranian borders, especially near to Khuzestan Province in the south-west of Iran. This is the only non-buthid scorpion which is potentially lethal in southern Iran and is responsible for severe dermonecrotic scorpionism. OBJECTIVES: In this study, DNA fragment of the mitochondrial cytochrome c oxidase ...

Evidence for the presence of a quinol oxidase super-complex composed of a cytochrome bc1 complex and cytochrome oxidase in the respiratory chain of a Gram-positive thermophilic bacterium PS3 is reported. On incubation with an octyl glucoside-solubilized fraction of the total membranes of PS3 anti-serum against PS3 cytochrome oxidase gave an immunoprecipitate that showed both quinol-cytochrome c...

Reversed electron transfer in submitochondrial particles causes the oxidation of cytochromes u3 + a and c, and reduction of cytochrome b upon addition of adenosine triphosphate, indicating a crossover point for the energy-linked reversal of electron transfer between cytochromes c and b. The cytochrome component designaged bbb5 is uniformly observed to show increased absorption in the low to hig...

Ilicicolin H is an antibiotic isolated from the "imperfect" fungus Cylindrocladium iliciola strain MFC-870. Ilicicolin inhibits mitochondrial respiration by inhibiting the cytochrome bc(1) complex. In order to identify the site of ilicicolin action within the bc(1) complex we have characterized the effects of ilicicolin on the cytochrome bc(1) complex of Saccharomyces cerevisiae. Ilicicolin inh...