* Transmembrane cytochrome b-like proteins: coenzyme Q-cytochrome c reductase ( cytochrome bc1 ); cytochrome b6f complex ; formate dehydrogenase, respiratory nitrate reductase ; succinate-coenzyme Q reductase ( fumarate reductase ); and succinate dehydrogenase.

* Cytochrome c nitrite reductase complex

This complex binds tightly to the enoyl-acyl carrier protein reductase known as InhA, thereby blocking the natural enoyl-AcpM substrate and the action of fatty acid synthase.

Succinate dehydrogenase or succinate-coenzyme Q reductase ( SQR ) or respiratory Complex II is an enzyme complex, bound to the inner mitochondrial membrane of mammalian mitochondria and many bacterial cells.

The lux operon has a known gene sequence of luxCDAB ( F ) E, where lux A and lux B code for the components of luciferase, and the lux CDE codes for a fatty acid reductase complex that makes the fatty acids necessary for the luciferase mechanism ( Meighen, 1991 ).

A rheumatoid arthritis drug ( auranofin, a gold ( I ) phosphine complex ) has shown value in treating parasitic disease through inhibiting thioredoxin glutathione reductase.

The cytochrome b < sub > 6 </ sub > f complex ( plastoquinol — plastocyanin reductase ; ) is an enzyme found in the thylakoid membrane in chloroplasts of plants, cyanobacteria, and green algae, catalyzing the transfer of electrons from plastoquinol to plastocyanin.

Cytochrome f is the largest subunit of cytochrome b < sub > 6 </ sub > f complex ( plastoquinol — plastocyanin reductase ; ).

Ubiquinol-cytochrome-c reductase ( also known as bc1 complex or complex III ) is an enzyme complex of bacterial and mitochondrial oxidative phosphorylation systems.

Finally, MEcPP is converted to ( E )- 4-hydroxy-3-methyl-but-2-enyl pyrophosphate ( HMB-PP ) by HMB-PP synthase ( GcpE, IspG ), and HMB-PP is converted to isopentenyl pyrophosphate ( IPP ) and dimethylallyl pyrophosphate ( DMAPP ) by HMB-PP reductase ( LytB, IspH ).

Spontaneously formed methemoglobin is normally reduced ( regenerating normal hemoglobin ) by protective enzyme systems, e. g., NADH methemoglobin reductase ( cytochrome-b5 reductase ) ( major pathway ), NADPH methemoglobin reductase ( minor pathway ) and to a lesser extent the ascorbic acid and glutathione enzyme systems.

Due to a deficiency of the enzyme diaphorase I ( NADH methemoglobin reductase ), methemoglobin levels rise and the blood of met-Hb patients has reduced oxygen-carrying capacity.

Figure 1: Schematic overview of the flavan-3-ol (-)- epicatechin biosynthesis in plants: Enzymes are indicated in blue, abbreviated as follows: E1, phenylalanine ammonia lyase ( PAL ), E2, tyrosine ammonia lyase ( TAL ), E3, cinnamate 4-hydroxylase, E4, 4-coumaroyl: CoA-ligase, E5, chalcone synthase ( naringenin-chalcone synthase ), E6, chalcone isomerase, E7, flavonoid 3 ´- hydroxylase, E8, flavonone 3-hydroxylase, E9, dihydroflavanol 4-reductase, E10, anthocyanidin synthase ( leucoanthocyanidin dioxygenase ), E11, anthocyanidin reductase.

By exposing cells to aminopterin ( a folic acid analogue, which inhibits dihydrofolate reductase, DHFR ), they are unable to use the de novo pathway and become fully auxotrophic for nucleic acids requiring supplementation to survive.

Triclosan binds to bacterial enoyl-acyl carrier protein reductase enzyme ( ENR ), which is encoded by the gene FabI.

* HMG-CoA ( 3-hydroxy-3-methylglutaryl-coenzyme A ), a metabolite in the HMG-CoA reductase pathway for cholesterol synthesis

AMPK also phosphorylates and inactivates 3-hydroxy-3-methylglutaryl-CoA reductase ( HMGCR ), a key enzyme in cholesterol synthesis.

The iron-dependent enzyme, ribonucleotide reductase ( RNR ), is essential for DNA synthesis.

Sequestration ( using filipin, nystatin or amphotericin ), depletion and removal ( using methyl-B-cyclodextrin ) and inhibition of cholesterol synthesis ( using HMG-CoA reductase inhibitors ) are ways cholesterol are manipulated in lipid raft studies.

Humans express three thioredoxin reductase isozymes: TrxR1 ( cytosolic ), TrxR2 ( mitochondrial ), TrxR3 ( testis specific ).

Dolichol is a product of the HMG-CoA reductase pathway ( also known as the mevalonate pathway ), and as such their creation and availability are affected by mevalonate inhibition.

This conserved region is also found as a domain in various metabolic enzymes and in multidomain proteins, such as aldehyde oxidoreductase ( N-terminal ), xanthine oxidase ( N-terminal ), phthalate dioxygenase reductase ( C-terminal ), succinate dehydrogenase iron-sulphur protein ( N-terminal ), and methane monooxygenase reductase ( N-terminal ).

Their target, aldose reductase, is an enzyme that is normally present in many other parts of the body, and catalyzes one of the steps in the sorbitol ( polyol ) pathway that is responsible for fructose formation from glucose.

The mevalonate pathway or HMG-CoA reductase pathway or mevalonate-dependent ( MAD ) route or isoprenoid pathway, is an important cellular metabolic pathway present in all higher eukaryotes and many bacteria.

NO can be produced by a yet undefined NO synthase, a special type of nitrite reductase, nitrate reductase, mitochondrial cytochrome c oxidase or non enzymatic processes and regulate plant cell organelle functions ( e. g. ATP synthesis in chloroplasts and mitochondria ).

In chloroplasts, Fe < sub > 2 </ sub > S < sub > 2 </ sub > ferredoxins function as electron carriers in the photosynthetic electron transport chain and as electron donors to various cellular proteins, such as glutamate synthase, nitrate reductase and sulfite reductase.

Selenium is a component of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase ( which indirectly reduce certain oxidized molecules in animals and some plants ).

The genus is so specialized for nutrient uptake through its carnivorous behavior, the pygmy sundew is missing the enzymes ( nitrate reductase, in particular )) that plants normally use for the uptake of earth-bound nitrates.

Bacterial dhfr ( dihydrofolate reductase ) gene was inserted in the CaMV genome in place of gene II, and was successfully expressed in plants.

Protein complexes in the inner membrane ( NADH dehydrogenase, cytochrome c reductase, and cytochrome c oxidase ) perform the transfer and the incremental release of energy is used to pump protons ( H < sup >+</ sup >) into the intermembrane space.

For example, it has been found to interact with NADPH cytochrome P450 reductase, associated with increased production of ROS, and glutathione S-transferase, responsible for production of the anti-oxidant glutathione.

* Microsomal P450 systems in which electrons are transferred from NADPH via cytochrome P450 reductase ( variously CPR, POR, or CYPOR ).

Cytochrome b5 ( cyb5 ) can also contribute reducing power to this system after being reduced by cytochrome b5 reductase ( CYB5R ).

In living muscle, the concentration of metmyoglobin is vanishingly small, due to the presence of the enzyme metmyoglobin reductase, which, in the presence of the cofactor NADH and the coenzyme cytochrome b4 converts the Fe < sup > 3 +</ sup > in the heme prosthetic group of metmyoglobin back to the Fe < sup > 2 +</ sup > of normal myoglobin.

In mitochondrial monooxygenase systems, adrenodoxin transfers an electron from NADPH: adrenodoxin reductase to membrane-bound cytochrome P450.

It also transfers electrons from adrenodoxin reductase to the cholesterol side chain cleavage cytochrome P450.

Cytochrome P450 reductase also known as NADPH: ferrihemoprotein oxidoreductase, NADPH: hemoprotein oxidoreductase, NADPH: P450 oxidoreductase, P450 reductase, POR, CPR, CYPOR, is a membrane-bound enzyme required for electron transfer to cytochrome P450 in the microsome of the eukaryotic cell from a FAD-and FMN-containing enzyme NADPH: cytochrome P450 reductase

Furthermore, the researchers found the bacterium creates a hyperinfected state where genes that control biosynthesis of amino acids, iron uptake systems, and formation of periplasmic nitrate reductase complexes were induced just before defecation.

In such cases, the enzyme methemoglobin reductase will be able to eventually reactivate methemoglobin by reducing the iron center.

The methemoglobin reductase enzyme may be under-produced or absent in certain people that have an inherited mutation.

Subsequently, tropinone reductase I ( EC 1. 1. 1. 206 ) converts tropinone to tropine which condenses with phenylalanine-derived phenyllactate to littorine.

5α-Reductase deficiency ( 5-ARD ) is an autosomal recessive intersex condition caused by a mutation of the 5α reductase type II gene.

DOPAL can also be reduced to 3, 4-dihydroxyphenylethanol ( DOPET ; also known as hydroxytyrosol ) by aldose reductase ( AR ) to a lesser extent.

The enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase ( HMG CoA reductase ) is an essential component in the pathway.

* Statins reduce high levels of LDL particles by inhibiting the enzyme HMG-CoA reductase in cells, the rate-limiting step of cholesterol synthesis.

In particular, gamma-tocotrienol appears to be another HMG-CoA reductase inhibitor, and can reduce cholesterol production.

* Insulin induces HMG-CoA reductase activity, whereas glucagon diminishes HMG-CoA reductase activity.

Testosterone is converted into dihydrotestosterone by the 5-alpha reductase enzyme.

Aldose reductase inhibitors are a class of drugs being studied as a way to prevent eye and nerve damage in people with diabetes.

Aldose reductase activity increases as the glucose concentration rises in diabetes in those tissues that are not insulin sensitive, which include the lenses, peripheral nerves and glomerulus.

The excess sugar within the lens is reduced by aldose reductase to its alcohol, but the lens capsule is relatively impermeable to sugar alcohols.

Topical administration of aldose reductase inhibitors have been shown to prevent the cataract in rats.

* This product is reduced to 2, 3, 4, 5-tetrahydrodipicolinate ( or Δ < sup > 1 </ sup >- piperidine-2, 6-dicarboxylate, in the figure: ( S )- 2, 3, 4, 5-tetrahydropyridine-2, 6-dicarboxylate ) by dihydrodipicolinate reductase.

The catalytic cycle for ribonucleotide reductase, demonstrating the role of thiyl radicals in producing the genetic machinery of life.

Flavin adenine dinucleotide is a group bound to many enzymes including ferredoxin-NADP + reductase, monoamine oxidase, D-amino acid oxidase, glucose oxidase, xanthine oxidase, and acyl CoA dehydrogenase.