Cytochrome c Reductase

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Introductions

Cytochrome c Reductase (CoQ) a fat-soluble quinone compound widely found in living organisms, differs in the number of isopentene units in the side chain of different sources of Cytochrome c Reductase, 10 isopentene units in humans and mammals, so it is called Coenzyme Q10. CoQ plays an important role in the proton shift and electron transfer in the respiratory chain in vivo, it is the activator of cellular respiration and cellular metabolism, and is also an important antioxidant and non-specific immune enhancer. It is an activator of cellular respiration and cellular metabolism, as well as an important antioxidant and non-specific immune enhancer.

Structure

The number of subunits found may be small compared to the other major proton pump subunits of the electron transport chain, with only three polypeptide chains. This number does increase, with 11 subunits found in higher animals. Three subunits have cofactors. The cytochrome b subunit has two b-type heme (b L and b H), the cytochrome c subunit has a c-type heme (c 1), and the Rieske iron-sulfur protein subunit (ISP) has a diiron disulfide iron-sulfur cluster (2Fe-2S).

Figure 1. Structure of Cytochrome c Reductase.

Distribution

CoQ is widely distributed in nature, mainly in the heart, liver and kidney cells of animals, as well as in yeast, plant leaves and seeds. CoQ has roles as a respiratory chain component involved in ATP synthesis, antioxidant, cardiovascular protection and anti-inflammatory.

CoQ is an electron carrier in the respiratory chain

CoQ is widely found in mitochondria. It is a component of the cellular respiratory chain and plays a role in the transfer of hydrogen and electrons. In the respiratory chain, complex I (NADH: coenzyme Q oxidoreductase complex) receives two electrons from NADH and passes them to CoQ via iron-sulfur protein. complex II (succinate dehydrogenase) receives electrons from succinate and passes them to CoQ. CoQ passes the electrons received from these two complexes to complex III (CoQ: cytochrome C oxidoreductase complex) and finally to oxygen. The transfer of electrons from FMN to coenzyme Q through the iron-sulfur cluster causes a conformational change in the proton channel, culminating in a proton translocation. CoQ is involved in the aerobic respiration process of cells and is closely related to the formation of ATP. Most of the energy in the human body is produced through the respiratory chain. Therefore, deficiency of coenzyme Q leads to impaired energy supply. Therefore, those organs with high energy requirements, such as the heart and kidneys, are more susceptible to coenzyme Q deficiency.

Figure 2. CoQ is an electron carrier in the respiratory chain.

Redox states

CoQ has three redox states: ubiquinone in the oxidized form, ubiquinol in the reduced form, and semiquinone radical in the intermediate state. Thus, it can carry two electrons and is a redox carrier. In the respiratory chain, CoQ is the only non-protein redox carrier. Its small molecular size and lipid solubility allow it to move rapidly through the membrane. These properties put it at the center of the electron transport chain, accepting hydrogen and electrons passing them down the chain.

Applications

Cardiovascular-related diseases, such as viral myocarditis and chronic cardiac insufficiency.

Hepatitis, such as: viral hepatitis, subacute hepatic necrosis and chronic active hepatitis.

Comprehensive treatment of cancer, CoQ can reduce some adverse reactions caused by radiotherapy, chemotherapy, etc.