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The subcellular distribution and some properties of the cytochrome b component of the microbicidal oxidase system of human neutrophils.

ABSTRACT: A novel cytochrome b has recently been described in human neutrophils. The subcellular distribution of this cytochrome was investigated by analytical fractionation on continuous sucrose gradients and it was found to have a dual localization, the major component having a similar distribution to the plasma-membrane marker [3H]concanavalin A, and a denser peak located with the specific granules. The two components were separated on discontinuous gradients and studied independently.

SUBMITTER: Segal AW

PROVIDER: S-EPMC1161247 | biostudies-other | 1979 Jul

REPOSITORIES: biostudies-other

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Changes in the subcellular distribution of the cytochrome b-245 on stimulation of human neutrophils.

Project description:Cytochrome b-245 of neutrophils has a bimodal distribution in sucrose density gradients. The lighter component (d = 1.14) is shown to be associated with the plasma membrane by the similarity between its density and that of markers of this organelle, as well as a parallel increase in the density of the cytochrome and plasma membrane after treatment with digitonin or dimethyl suberimidate. The cytochrome b-245 of monocytes and cytoplasts, the latter produced by the removal of nuclei and granules from neutrophils, was located only in the plasma membrane. The denser peak of cytochrome (d = 1.19), which contained approximately half of the cytochrome b of neutrophils, had a similar density-distribution profile to the specific granules. After hypo-osmotic disruption of this denser material, the cytochrome distributed with the density of membranes, suggesting an original location within the membrane of the intracellular structure. Redistribution of the cytochrome from the granules to the membranes was observed after stimulation of respiratory activity with soluble agents or opsonized particles. This translocation is not responsible for activation of the oxidase system. There was poor agreement between the kinetics of the transfer of cytochromes from the dense component to the membranes, and degranulation of specific-granule contents, suggesting that the cytochrome may be located in another intracellular structure or that its localization becomes further modified after granule fusion.

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The effect of the NADPH oxidase inhibitor diphenyleneiodonium on aerobic and anaerobic microbicidal activities of human neutrophils.

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2020-10-07 | GSE159080 | GEO

Oxidation-reduction properties of the cytochrome b found in the plasma-membrane fraction of human neutrophils. A possible oxidase in the respiratory burst.

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Some magnetic properties of Pseudomonas cytochrome oxidase.

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MrpL35, a mitospecific component of mitoribosomes, plays a key role in cytochrome c oxidase assembly.

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The subcellular localization of ubiquinone in human neutrophils.

Project description:Ubiquinone-10 has recently been proposed as a component of the microbicidal oxidase system of neutrophil leukocytes [Crawford & Schneider (1982) J. Biol. Chem. 257, 6662-6668]. We have determined the subcellular localization of ubiquinone and could detect it only in the mitochondrial fractions. It was not enriched in phagolysosomes which were enriched in O2-. generating activity and cytochrome b-245. It is proposed that ubiquinone is unlikely to play a direct role in the electron transport chain located in the plasma membrane which functions to produce microbicidal oxygen radicals.

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