1. The topography of cytochrome P-450 in vesicles from smooth endoplasmic reticulum of rat liver has been examined. Approx. 50% of the cytochrome is directly accessible to the action of trypsin in intact vesicles whereas the remainder is inaccessible and partitioned between luminal-facing or phospholipid-embedded loci. Analysis by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis revea...

It has been shown that cytochrome c is released from mitochondria during apoptosis, activates pro-caspase CPP32 (caspase III), and induces DNA fragmentation in mixtures of cytosolic extracts and isolated nuclei. To establish whether cytochrome c can primarily induce apoptosis in intact cells, we used direct electroporation of cytochrome c into murine interleukin-3 (IL-3)-dependent cells. Electr...

In this work, we measured the effect of cytochrome c on the NADH-dependent superoxide anion production by synaptic plasma membrane vesicles from rat brain. In these membranes, the cytochrome c stimulated NADH-dependent superoxide anion production was inhibited by antibodies against cytochrome b5 reductase linking the production to this enzyme. Measurement of the superoxide anion radical generat...

The genome of the ethanol-producing bacterium Zymomonas mobilis encodes a bd-type terminal oxidase, cytochrome bc1 complex and several c-type cytochromes, yet lacks sequences homologous to any of the known bacterial cytochrome c oxidase genes. Recently, it was suggested that a putative respiratory cytochrome c peroxidase, receiving electrons from the cytochrome bc1 complex via cytochrome c552, ...

quinol oxidation inhibitors (qois) are one of the most important classes of fungicides used in agriculture. they block electron transfer between cytochrome b and cytochrome c1, thereby impeding the production of atp via oxidative phosphorylation. qoi fungicides are generally at high risk of provoking resistance in fungal phytopathogens. resistance has been reported in more than thirty species, ...

background: polycyclic aromatic hydrocarbons (pahs) are a predominant group of contaminants that have been shown to accumulate and persist in marine organisms. we evaluated the dose-dependent induction of the cytochrome p4501a (cyp1a) system in the sturgeon fish, huso huso after after exposure to pahs, beta-naphthoflavone (bnf) and 3- methylcholantheren. methods: the fish were treated by i.p. i...

Cytochrome c oxidase isolated from beef heart mitochondria was reconstituted in bilayer membranes of the anionic lipid dimyristoylphosphatidylglycerol (DMPG) with varying enzyme/DMPG ratio. Lipid-protein interactions in the reconstituted membrane complexes were studied in the presence and absence of saturating amounts of bound cytochrome c, by both chemical binding assays and spin-label ESR spe...

A method is described which allows the direct measurement of intermembrane protein transfer. We have used this method to examine the transfer of cytochrome bg from artificial phospholipid vesicles and biological membranes. !l!his method involves the incubation of small, sonicated phospholipid vesicles with either biological membranes or large unilamellar phospholipid vesicles (Enoch, H. G., and...

Conidia of Verticillium albo-atrum Reinke and Berthold, collected from shake cultures grown in Czapek broth, were sonified for 4 or 8 minutes or ground frozen in a mortar to obtain cell-free homogenates. These were assayed for certain enzymes associated with respiratory pathways. Malic dehydrogenase was the most active, glucose-6-P and NADH dehydrogenase were less active, NADH-cytochrome c redu...

The role of TPNH as the donor of reducing equivalents to microsomal mixed function oxidations of drugs, other foreign compounds, and steroids in the liver is well established (1-5). DPNH will not substitute for TPNH in the cyt#{243}chrome P-450-mediated oxidation of drugs, but reaction rates are increased when both nucleotides are present (61 1 ). Although this synergistic role of DPNH has been...