Cytochrome Oxidase

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Related to Cytochrome Oxidase: Cytochrome P450

cytochrome oxidase

[′sīd·ə‚krōm ′äk·sə‚dās]
Any of a family of respiratory pigments that react directly with oxygen in the reduced state. Also known as cytochrome a3.

Cytochrome Oxidase


(also cytochrome a3), an enzyme of the oxido-reductase class; the final component of the chain of respiratory enzymes that carry electrons from the cytochrome c to molecular oxygen. Cytochrome oxidase was discovered in 1926 by the German scientist O. Warburg (Warburg’s respiratory enzyme). In plant and animal cells, it is localized on the inner membrane of mitochrondria. Chemically, it is a complex protein, whose molecule consists of two hemes, two copper atoms, and 20–30 percent lipid constituent. Both hemes are heme a; however, only part of the heme a is oxidized, and it is designated a3. It is still unclear whether cytochrome oxidase is a single protein with two functionally different forms of heme, or whether it is a complex of two different cytochromes. Copper is bound to the protein by a sulfur-containing ligand. When the copper is separated from the protein, cytochrome oxidase becomes inactive.

The molecular weight of cytochrome oxidase varies, according to different data, from 50,000 to 240,000. Cyanide, azide, CO, and hydroxylamine are cytochrome oxidase inhibitors.


References in periodicals archive ?
albopictus, and correspond to positions 1658 to 2393 of the mitochondrial gene cytochrome oxidase I (reference sequence in GenBank AY072044.
1) were used to obtain individual sequences of the mitochondrial (mtDNA) gene cytochrome oxidase c subunit 1 (CO1), and the nuclear (nDNA) genes 18S and 28S.
Though cytochrome oxidase subunit I (COI) is a commonly used mitochondrial gene in barcoding studies, it did not readily amplify in our samples; however, we successfully amplified cytochrome oxidase B, another commonly used mitochondrial marker.
Cytochrome oxidase activity in skeletal muscle and the diaphragm of intermittently starving rats.
Cytochrome oxidase (COx) is a mitochondrial enzyme that participates in the oxidative phosphorylation process in which energy is produced in the form of ATP Therefore, COx activity reflects changes in the neuronal metabolic capacity induced by energy requirements and is an indicator of neuronal activity of brain regions in response to learning processes including spatial learning (Conejo, Gonzalez-Pardo, Lopez, Cantora, & Arias, 2007; Gonzalez-Lima & Cada, 1994; Mendez-Lopez, Mendez, Lopez, & Arias, 2009).
Vestling, Frajola wrote his dissertation on "Investigations of the Cytochrome c Cytochrome Oxidase System" that was published in part and co-authored with Vestling (J.
Mitochondrial genes (including cytochrome oxidase I and the 12S and 16S rRNAs) were most commonly sequenced, with some nuclear genes (including histone genes and the 5.
DNA barcoding --the sequencing of a 650 bp region of the cytochrome oxidase I gene of the mitochondrial DNA molecule--enables the ready separation of about 97% of all shark and ray species.
The cytochrome oxidase is an important enzyme of oxidative phosphorylation in respiratory chain.
After incubation of these cultures overnight at 35[degrees]C, a portion of the slant culture was used for the cytochrome oxidase test.
Demant (1993) reported that inhibition of cytochrome oxidase activity by the adriamycin--[Fe.
Subsequent tests of succinate-dependent O uptake, alternative oxidase activity, cytochrome oxidase, duroquinol-dependant O uptake, and cytochrome b[c.