QuickView for Heme (compound)

Hemoglobin-like protein that exhibits a low peroxidase activity. Its very high oxygen affinity may rule out the possibility that it is involved in oxygen transport

Involved in the coupling of aromatic side chains of the heptapeptide of vancomycin

May form part of a transmembrane redox complex through which electrons are transferred to the cytoplasm for reduction of sulfate

Allows the bacteria to use the host heme as an iron source. Involved in the oxidation of heme and subsequent release of iron from the heme moiety

May perform analogous functions in iron detoxification and storage to that of animal ferritins (By similarity)

Electron acceptor for MDH. Acts in methanol oxidation

Has phosphodiesterase activity with cAMP but not with cGMP, bis(p-nitrophenyl) phosphate or p-nitrophenyl phosphate

May have a protective function during conditions of oxidative stress. May be involved in intracellular oxygen storage or transfer

Catalyzes unidirectional fumarate reduction using artificial electron donors such as methyl viologen. The physiological reductant is unknown

Low-potential cytochrome c that plays a possible role in water oxidation complex of photosystem II

Forms a very stable complex with oxygen. The oxygen dissociation rate is 0.011 s(-1)

Catalyzes fumarate reduction using artificial electron donors such as methyl viologen. The physiological reductant is unknown, but evidence indicates that flavocytochrome c participates in electron transfer from formate to fumarate and possibly also to trimethylamine oxide (TMAO). This enzyme is essentially unidirectional

Involved in a camphor oxidation system

Produces nitric oxide (NO) which is a messenger molecule with diverse functions throughout the body. In the brain and peripheral nervous system, NO displays many properties of a neurotransmitter

Participates in sulfate respiration coupled with phosphorylation by transferring electrons from the enzyme dehydrogenase to ferredoxin

Catalyzes fumarate reduction using artificial electron donors such as methyl viologen. The physiological reductant is unknown, but evidence indicates that flavocytochrome c participates in electron transfer from formate to fumarate and possibly also to trimethylamine oxide (TMAO). This enzyme is essentially unidirectional

Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics. In the epoxidation of arachidonic acid it generates only 14,15- and 11,12-cis-epoxyeicosatrienoic acids. It is the principal enzyme responsible for the metabolism the anti- cancer drug paclitaxel (taxol)

Occurs in almost all aerobically respiring organisms and serves to protect cells from the toxic effects of hydrogen peroxide

Electron-transport protein of unknown function

High-spin cytochrome. Transiently bind oxygen during autoxidation, which occurs with a half-life of 3 min with a 4-fold excess of O(2). Also binds carbon monoxide, azide and cyanide

Heme oxygenase cleaves the heme ring at the alpha methene bridge to form biliverdin. Biliverdin is subsequently converted to bilirubin by biliverdin reductase. Under physiological conditions, the activity of heme oxygenase is highest in the spleen, where senescent erythrocytes are sequestrated and destroyed

Heme-containing signal transducer responsible for aerotaxis, the migratory response toward or away from oxygen

Plays a role in nitrite reduction

Catalyzes the production of nitric oxide

Involved in the biosynthesis of epothilones, macrolactones which have a narrow anti-fungal spectrum and microtubule-stabilizing activity. Responsible for the epooxidation of epothilones C and D to epothilones A and B, respectively

Has 2-hydroxyacid oxidase activity. Most active on the 2-carbon substrate glycolate, but is also active on 2-hydroxy fatty acids

Produces nitric oxide (NO) which is implicated in vascular smooth muscle relaxation through a cGMP-mediated signal transduction pathway. No mediates vascular endothelial growth factor (VEGF)-induced angiogenesis in coronary vessels and promotes blood clotting through the activation of platelets

Electron donor for cytochrome cd1 in nitrite and nitrate respiration

May play an important role in regulating or promoting cell proliferation in some normal and neoplastically transformed cells

Binds oxygen cooperatively with very high affinity (P(50) = 0.013 mmHg at 20 degrees Celsius) because of a fast combination (25 microM(-1).s(-1)) and a slow dissociation (0.2 s(- 1)) rate

Produces nitric oxide (NO) which is a messenger molecule with diverse functions throughout the body. In macrophages, NO mediates tumoricidal and bactericidal actions

Involved in ammonia oxidation; accepts electrons directly from hydroxylamine oxidoreductase (HAO)

Catalyzes the production of nitric oxide

Involved in the coupling of aromatic side chains of the heptapeptide of vancomycin

Plays a role in apoptosis. Suppression of the anti- apoptotic members or activation of the pro-apoptotic members of the Bcl-2 family leads to altered mitochondrial membrane permeability resulting in release of cytochrome c into the cytosol. Binding of cytochrome c to Apaf-1 triggers the activation of caspase-9, which then accelerates apoptosis by activating other caspases

Cytochrome c2 is found mainly in purple, non-sulfur, photosynthetic bacteria where it functions as the electron donor to the oxidized bacteriochlorophyll in the photophosphorylation pathway. However, it may also have a role in the respiratory chain and is found in some non-photosynthetic bacteria

4 ferrocytochrome c + O(2) = 4 ferricytochrome c + 2 H(2)O

Bifunctional, exhibiting both a catalase and broad- spectrum peroxidase activities. May play a role in the intracellular survival of mycobacteria

This monoheme basic protein appears to function as an electron donor to cytochrome oxidase in T.thermophilus

Cytochrome c2 is found mainly in purple, non-sulfur, photosynthetic bacteria where it functions as the electron donor to the oxidized bacteriochlorophyll in the photophosphorylation pathway. However, it may also have a role in the respiratory chain and is found in some non-photosynthetic bacteria

Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide

Small subunit of the periplasmic nitrate reductase (NAP). Only expressed at high levels during aerobic growth. NapAB complex receives electrons from the membrane-anchored tetraheme napC protein, thus allowing electron flow between membrane and periplasm. Essential function for nitrate assimilation and may have a role in anaerobic metabolism (By similarity)

Functions as an electron carrier between membrane-bound cytochrome b6-f and photosystem I in oxygenic photosynthesis

Diheme, high potential cytochrome c believed to be an intermediate electron donor to terminal oxidation systems

Putative oxygen sensor; modulates the activity of fixJ, a transcriptional activator of nitrogen fixation fixK gene. FixL probably acts as a kinase that phosphorylates fixJ

Participates in sulfate respiration coupled with phosphorylation by transferring electrons from the enzyme dehydrogenase to ferredoxin

Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide

This protein functions as a terminal oxidase

Natural electron acceptor for a formate dehydrogenase

Participates in sulfate respiration coupled with phosphorylation by transferring electrons from the enzyme dehydrogenase to ferredoxin

Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide

Putative oxygen sensor; modulates the activity of fixJ, a transcriptional activator of nitrogen fixation fixK gene. FixL probably acts as a kinase that phosphorylates fixJ

Functions as a fatty acid monooxygenase. Catalyzes hydroxylation of medium and long-chain fatty acids at omega-1, omega-2 and omega-3 positions, with optimum chain lengths of 12-16 carbons (lauric, myristic, and palmitic acids). The reductase domain is required for electron transfer from NADP to cytochrome P450

Involved in oxygen transport from the lung to the various peripheral tissues

Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide

Plays a role in nitrite reduction

Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics

Cytochrome c' is the most widely occurring bacterial c- type cytochrome. Cytochromes c' are high-spin proteins and the heme has no sixth ligand. Their exact function is not known

Catalyzes the opening of the heme ring with the release of iron. Key enzyme in the synthesis of the chromophoric part of the photosynthetic antennae

Its precise biological substrate is not known. Catalyzes C14-demethylation of lanosterol, 24,25-dihydrolanosterol and obtusifoliol which is critical for ergosterol biosynthesis. It transforms lanosterol into 4,4'-dimethyl cholesta-8,14,24-triene- 3-beta-ol

May have a role as a major mediator of inflammation and/or a role for prostanoid signaling in activity-dependent plasticity

Catalyzes the alpha- and beta-hydroxylation of myristic acid in the presence of hydrogen peroxide

Conversion of 6-deoxyerythronolide B (6-DEB) to erythronolide B (EB) by the insertion of an oxygen at the 6S position of 6-DEB

Low-potential cytochrome c that plays a role in water oxidation complex of photosystem II

Can bind free heme and also acquire it from hemoglobin. Conveys heme from hemoglobin to the HasR receptor which releases it into the bacterium. HasR alone can take up heme but the synergy between HasA and HasR increases heme uptake 100-fold

This monoheme basic protein appears to function as an electron donor to cytochrome oxidase in T.thermophilus

Exchanges electrons specifically with the basic cytochrome c3

Cytochrome c2 is found mainly in purple, non-sulfur, photosynthetic bacteria where it functions as the electron donor to the oxidized bacteriochlorophyll in the photophosphorylation pathway. However, it may also have a role in the respiratory chain and is found in some non-photosynthetic bacteria

HMWC (high-molecular-weight cytochrome c), ORF2, ORF3, ORF4, ORF5 and ORF6 in the HMC operon form a transmembrane protein complex that allows electron flow from the periplasmic hydrogenase to the cytoplasmic enzymes that catalyze reduction of sulfates

May perform analogous functions in iron detoxification and storage to that of animal ferritins

Nitric oxide + H(2)O + ferricytochrome c = nitrite + ferrocytochrome c + 2 H(+)

Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics. This enzyme contributes to the wide pharmacokinetics variability of the metabolism of drugs such as S- warfarin, diclofenac, phenytoin, tolbutamide and losartan

In the presence of oxygen and NADH, FHP has NADH oxidase activity, which leads to the generation of superoxide and H(2)O(2), both in vitro and in vivo, and it has been suggested that FHP might act as an amplifier of superoxide stress. Under anaerobic conditions, FHP also exhibits nitric oxide reductase and FAD reductase activities. However, all these reactions are much lower than NOD activity

Cytochrome c' is the most widely occurring bacterial c- type cytochrome. Cytochromes c' are high-spin proteins and the heme has no sixth ligand. Their exact function is not known

Various electron acceptors are also reduced by HMP in vitro, including dihydropterine, ferrisiderophores, ferric citrate, cytochrome c, nitrite, S-nitrosoglutathione, and alkylhydroperoxides. However, it is unknown if these reactions are of any biological significance in vivo

Low-spin monoheme cytochrome c

Component of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI), cyclic electron flow around PSI, and state transitions (By similarity)

Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide

Cytochrome c2 is found mainly in purple, non-sulfur, photosynthetic bacteria where it functions as the electron donor to the oxidized bacteriochlorophyll in the photophosphorylation pathway. However, it may also have a role in the respiratory chain and is found in some non-photosynthetic bacteria

Catalyzes the opening of the heme ring with the release of iron. Key enzyme in the synthesis of the chromophoric part of the photosynthetic antennae (By similarity)

Involved in oxygen transport in the brain

Cytochrome b5 is a membrane bound hemoprotein which function as an electron carrier for several membrane bound oxygenases

Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics

Sulfite + O(2) + H(2)O = sulfate + H(2)O(2)

2 ferrocytochrome c + H(2)O(2) = 2 ferricytochrome c + 2 H(2)O

Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It performs a variety of oxidation reactions (e.g. caffeine 8-oxidation, omeprazole sulphoxidation, midazolam 1'-hydroxylation and midazolam 4- hydroxylation) of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics. The enzyme also hydroxylates etoposide

Catalyzes the oxidation of hydroxylamine to nitrite. The electrons released in the reaction are partitioned to ammonium monooxygenase and to the respiratory chain. The immediate acceptor of electrons from HAO is cytochrome c-554

When expressed in E.coli and M.smegmatis, HbO increases oxygen uptake. Membrane vesicles of E.coli carrying HbO show a respiration activity about twice that of membranes without HbO. HbO seems to interact with a terminal oxidase. Therefore, HbO could participate in oxygen/electron-transfer process, suggesting a function related to the facilitation of oxygen transfer during aerobic metabolism of M.tuberculosis

Serum albumin, the main protein of plasma, has a good binding capacity for water, Ca(2+), Na(+), K(+), fatty acids, hormones, bilirubin and drugs. Its main function is the regulation of the colloidal osmotic pressure of blood