NADH Dehydrogenase
A flavoprotein and iron sulfur-containing oxidoreductase that catalyzes the oxidation of NADH to NAD. In eukaryotes the enzyme can be found as a component of mitochondrial electron transport complex I. Under experimental conditions the enzyme can use CYTOCHROME C GROUP as the reducing cofactor. The enzyme was formerly listed as EC 1.6.2.1.
Cytochrome Reductases
Cytochrome reductases are enzymes that catalyze the transfer of electrons from donor molecules to cytochromes in electron transport chains, playing a crucial role in cellular respiration and energy production within cells.
NAD
A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)
L-Lactate Dehydrogenase
NADH, NADPH Oxidoreductases
A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.
Electron Transport Complex I
A flavoprotein and iron sulfur-containing oxidoreductase complex that catalyzes the conversion of UBIQUINONE to ubiquinol. In MITOCHONDRIA the complex also couples its reaction to the transport of PROTONS across the internal mitochondrial membrane. The NADH DEHYDROGENASE component of the complex can be isolated and is listed as EC 1.6.99.3.
Alcohol Dehydrogenase
A zinc-containing enzyme which oxidizes primary and secondary alcohols or hemiacetals in the presence of NAD. In alcoholic fermentation, it catalyzes the final step of reducing an aldehyde to an alcohol in the presence of NADH and hydrogen.
Malate Dehydrogenase
Succinate Dehydrogenase
A flavoprotein containing oxidoreductase that catalyzes the dehydrogenation of SUCCINATE to fumarate. In most eukaryotic organisms this enzyme is a component of mitochondrial electron transport complex II.
Glyceraldehyde-3-Phosphate Dehydrogenases
Rotenone
A botanical insecticide that is an inhibitor of mitochondrial electron transport.
Glycerolphosphate Dehydrogenase
Mitochondria
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Aldehyde Dehydrogenase
Glutamate Dehydrogenase
Electron Transport
Glucosephosphate Dehydrogenase
Glucose-6-Phosphate Dehydrogenase (G6PD) is an enzyme that plays a critical role in the pentose phosphate pathway, catalyzing the oxidation of glucose-6-phosphate to 6-phosphoglucono-δ-lactone while reducing nicotinamide adenine dinucleotide phosphate (NADP+) to nicotinamide adenine dinucleotide phosphate hydrogen (NADPH), thereby protecting cells from oxidative damage and maintaining redox balance.
Isocitrate Dehydrogenase
An enzyme of the oxidoreductase class that catalyzes the conversion of isocitrate and NAD+ to yield 2-ketoglutarate, carbon dioxide, and NADH. It occurs in cell mitochondria. The enzyme requires Mg2+, Mn2+; it is activated by ADP, citrate, and Ca2+, and inhibited by NADH, NADPH, and ATP. The reaction is the key rate-limiting step of the citric acid (tricarboxylic) cycle. (From Dorland, 27th ed) (The NADP+ enzyme is EC 1.1.1.42.) EC 1.1.1.41.
Oxidoreductases
The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)
Quinone Reductases
NAD(P)H:(quinone acceptor) oxidoreductases. A family that includes three enzymes which are distinguished by their sensitivity to various inhibitors. EC 1.6.99.2 (NAD(P)H DEHYDROGENASE (QUINONE);) is a flavoprotein which reduces various quinones in the presence of NADH or NADPH and is inhibited by dicoumarol. EC 1.6.99.5 (NADH dehydrogenase (quinone)) requires NADH, is inhibited by AMP and 2,4-dinitrophenol but not by dicoumarol or folic acid derivatives. EC 1.6.99.6 (NADPH dehydrogenase (quinone)) requires NADPH and is inhibited by dicoumarol and folic acid derivatives but not by 2,4-dinitrophenol.
DNA, Mitochondrial
Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.
Alcohol Oxidoreductases
A subclass of enzymes which includes all dehydrogenases acting on primary and secondary alcohols as well as hemiacetals. They are further classified according to the acceptor which can be NAD+ or NADP+ (subclass 1.1.1), cytochrome (1.1.2), oxygen (1.1.3), quinone (1.1.5), or another acceptor (1.1.99).
Dihydrolipoamide Dehydrogenase
A flavoprotein containing oxidoreductase that catalyzes the reduction of lipoamide by NADH to yield dihydrolipoamide and NAD+. The enzyme is a component of several MULTIENZYME COMPLEXES.
Oxidation-Reduction
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Carbohydrate Dehydrogenases
Reversibly catalyze the oxidation of a hydroxyl group of carbohydrates to form a keto sugar, aldehyde or lactone. Any acceptor except molecular oxygen is permitted. Includes EC 1.1.1.; EC 1.1.2.; and 1.1.99.
L-Iditol 2-Dehydrogenase
An alcohol oxidoreductase which catalyzes the oxidation of L-iditol to L-sorbose in the presence of NAD. It also acts on D-glucitol to form D-fructose. It also acts on other closely related sugar alcohols to form the corresponding sugar. EC 1.1.1.14
NADP
Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)
NAD(P)H Dehydrogenase (Quinone)
A flavoprotein that reversibly catalyzes the oxidation of NADH or NADPH by various quinones and oxidation-reduction dyes. The enzyme is inhibited by dicoumarol, capsaicin, and caffeine.
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Flavin Mononucleotide
Mitochondria, Heart
Hydroxysteroid Dehydrogenases
Glucose 1-Dehydrogenase
Oxygen Consumption
Amino Acid Sequence
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Ketoglutarate Dehydrogenase Complex
The Ketoglutarate Dehydrogenase Complex is a multi-enzyme complex involved in the citric acid cycle, catalyzing the oxidative decarboxylation of alpha-ketoglutarate to succinyl-CoA and CO2, thereby connecting the catabolism of amino acids, carbohydrates, and fats to the generation of energy in the form of ATP.
Submitochondrial Particles
The various filaments, granules, tubules or other inclusions within mitochondria.
Sugar Alcohol Dehydrogenases
Reversibly catalyzes the oxidation of a hydroxyl group of sugar alcohols to form a keto sugar, aldehyde or lactone. Any acceptor except molecular oxygen is permitted. Includes EC 1.1.1.; EC 1.1.2. and EC 1.1.99.
Glucose Dehydrogenases
D-Glucose:1-oxidoreductases. Catalyzes the oxidation of D-glucose to D-glucono-gamma-lactone and reduced acceptor. Any acceptor except molecular oxygen is permitted. Includes EC 1.1.1.47; EC 1.1.1.118; EC 1.1.1.119 and EC 1.1.99.10.
Phosphogluconate Dehydrogenase
An enzyme of the oxidoreductase class that catalyzes the reaction 6-phospho-D-gluconate and NADP+ to yield D-ribulose 5-phosphate, carbon dioxide, and NADPH. The reaction is a step in the pentose phosphate pathway of glucose metabolism. (From Dorland, 27th ed) EC 1.1.1.43.
Flavin-Adenine Dinucleotide
Ubiquinone
A lipid-soluble benzoquinone which is involved in ELECTRON TRANSPORT in mitochondrial preparations. The compound occurs in the majority of aerobic organisms, from bacteria to higher plants and animals.
Base Sequence
Electron Transport Complex IV
A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.
IMP Dehydrogenase
An enzyme that catalyzes the dehydrogenation of inosine 5'-phosphate to xanthosine 5'-phosphate in the presence of NAD. EC 1.1.1.205.
Lactate Dehydrogenases
Formate Dehydrogenases
Flavoproteins that catalyze reversibly the reduction of carbon dioxide to formate. Many compounds can act as acceptors, but the only physiologically active acceptor is NAD. The enzymes are active in the fermentation of sugars and other compounds to carbon dioxide and are the key enzymes in obtaining energy when bacteria are grown on formate as the main carbon source. They have been purified from bovine blood. EC 1.2.1.2.
Xanthine Dehydrogenase
Escherichia coli
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Acyl-CoA Dehydrogenase
A flavoprotein oxidoreductase that has specificity for medium-chain fatty acids. It forms a complex with ELECTRON TRANSFERRING FLAVOPROTEINS and conveys reducing equivalents to UBIQUINONE.
17-Hydroxysteroid Dehydrogenases
Genes, Mitochondrial
Hydroxybutyrate Dehydrogenase
Iron-Sulfur Proteins
Multienzyme Complexes
Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES.
3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)
A ketone oxidoreductase that catalyzes the overall conversion of alpha-keto acids to ACYL-CoA and CO2. The enzyme requires THIAMINE DIPHOSPHATE as a cofactor. Defects in genes that code for subunits of the enzyme are a cause of MAPLE SYRUP URINE DISEASE. The enzyme was formerly classified as EC 1.2.4.3.
Succinates
Derivatives of SUCCINIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a 1,4-carboxy terminated aliphatic structure.
3-Hydroxyacyl CoA Dehydrogenases
Enzymes that reversibly catalyze the oxidation of a 3-hydroxyacyl CoA to 3-ketoacyl CoA in the presence of NAD. They are key enzymes in the oxidation of fatty acids and in mitochondrial fatty acid synthesis.
Pyruvate Dehydrogenase (Lipoamide)
Substrate Specificity
Hydrogen-Ion Concentration
11-beta-Hydroxysteroid Dehydrogenases
Flavins
Derivatives of the dimethylisoalloxazine (7,8-dimethylbenzo[g]pteridine-2,4(3H,10H)-dione) skeleton. Flavin derivatives serve an electron transfer function as ENZYME COFACTORS in FLAVOPROTEINS.
Naphthacenes
Alanine Dehydrogenase
An NAD-dependent enzyme that catalyzes the reversible DEAMINATION of L-ALANINE to PYRUVATE and AMMONIA. The enzyme is needed for growth when ALANINE is the sole CARBON or NITROGEN source. It may also play a role in CELL WALL synthesis because L-ALANINE is an important constituent of the PEPTIDOGLYCAN layer.
Uridine Diphosphate Glucose Dehydrogenase
NADPH Dehydrogenase
A flavoprotein that reversibly oxidizes NADPH to NADP and a reduced acceptor. EC 1.6.99.1.
Mutation
Dihydrouracil Dehydrogenase (NADP)
Succinic Acid
A water-soluble, colorless crystal with an acid taste that is used as a chemical intermediate, in medicine, the manufacture of lacquers, and to make perfume esters. It is also used in foods as a sequestrant, buffer, and a neutralizing agent. (Hawley's Condensed Chemical Dictionary, 12th ed, p1099; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1851)
Dimethylamines
Glucosephosphate Dehydrogenase Deficiency
Malates
"Malate" is a term used in biochemistry to refer to a salt or ester of malic acid, a dicarboxylic acid found in many fruits and involved in the citric acid cycle, but it does not have a specific medical definition as such.
Sequence Homology, Amino Acid
Electrophoresis, Polyacrylamide Gel
Cloning, Molecular
Cattle
3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
A 3-hydroxysteroid dehydrogenase which catalyzes the reversible reduction of the active androgen, DIHYDROTESTOSTERONE to 5 ALPHA-ANDROSTANE-3 ALPHA,17 BETA-DIOL. It also has activity towards other 3-alpha-hydroxysteroids and on 9-, 11- and 15- hydroxyprostaglandins. The enzyme is B-specific in reference to the orientation of reduced NAD or NADPH.
Antimycin A
Butyryl-CoA Dehydrogenase
A flavoprotein oxidoreductase that has specificity for short-chain fatty acids. It forms a complex with ELECTRON-TRANSFERRING FLAVOPROTEINS and conveys reducing equivalents to UBIQUINONE.
11-beta-Hydroxysteroid Dehydrogenase Type 1
Mitochondrial Proteins
Proteins encoded by the mitochondrial genome or proteins encoded by the nuclear genome that are imported to and resident in the MITOCHONDRIA.
Mannitol Dehydrogenases
Oxidative Phosphorylation
Flavoproteins
Flavoproteins are a type of protein molecule that contain noncovalently bound flavin mononucleotide or flavin adenine dinucleotide as cofactors, involved in various redox reactions and metabolic pathways, such as electron transfer, energy production, and DNA repair.
Hydroxyprostaglandin Dehydrogenases
Retinal Dehydrogenase
A metalloflavoprotein enzyme involved the metabolism of VITAMIN A, this enzyme catalyzes the oxidation of RETINAL to RETINOIC ACID, using both NAD+ and FAD coenzymes. It also acts on both the 11-trans- and 13-cis-forms of RETINAL.
Metalloproteins
Kinetoplastida
Aerobiosis
Life or metabolic reactions occurring in an environment containing oxygen.
20-Hydroxysteroid Dehydrogenases
Mitochondria, Liver
Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)
Cytochromes
Hemeproteins whose characteristic mode of action involves transfer of reducing equivalents which are associated with a reversible change in oxidation state of the prosthetic group. Formally, this redox change involves a single-electron, reversible equilibrium between the Fe(II) and Fe(III) states of the central iron atom (From Enzyme Nomenclature, 1992, p539). The various cytochrome subclasses are organized by the type of HEME and by the wavelength range of their reduced alpha-absorption bands.
Binding Sites
Oxygen
11-beta-Hydroxysteroid Dehydrogenase Type 2
An high-affinity, NAD-dependent 11-beta-hydroxysteroid dehydrogenase that acts unidirectionally to catalyze the dehydrogenation of CORTISOL to CORTISONE. It is found predominantly in mineralocorticoid target tissues such as the KIDNEY; COLON; SWEAT GLANDS; and the PLACENTA. Absence of the enzyme leads to a fatal form of childhood hypertension termed, APPARENT MINERALOCORTICOID EXCESS SYNDROME.
Cytochromes b
Cytochromes of the b group that have alpha-band absorption of 563-564 nm. They occur as subunits in MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III.
Electron Spin Resonance Spectroscopy
A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.
Acyl-CoA Dehydrogenase, Long-Chain
A flavoprotein oxidoreductase that has specificity for long-chain fatty acids. It forms a complex with ELECTRON-TRANSFERRING FLAVOPROTEINS and conveys reducing equivalents to UBIQUINONE.
Homoserine Dehydrogenase
Glucose
A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.
Isoenzymes
Macromolecular Substances
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
Leucine Dehydrogenase
An octameric enzyme belonging to the superfamily of amino acid dehydrogenases. Leucine dehydrogenase catalyzes the reversible oxidative deamination of L-LEUCINE, to 4-methyl-2-oxopentanoate (2-ketoisocaproate) and AMMONIA, with the corresponding reduction of the cofactor NAD+.
Phosphoglycerate Dehydrogenase
Isovaleryl-CoA Dehydrogenase
3-Isopropylmalate Dehydrogenase
Anaerobiosis
The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Optic Atrophies, Hereditary
Hereditary conditions that feature progressive visual loss in association with optic atrophy. Relatively common forms include autosomal dominant optic atrophy (OPTIC ATROPHY, AUTOSOMAL DOMINANT) and Leber hereditary optic atrophy (OPTIC ATROPHY, HEREDITARY, LEBER).
Pyruvate Dehydrogenase (Lipoamide)-Phosphatase
Immunoelectrophoresis, Two-Dimensional
Electron Transport Complex III
A multisubunit enzyme complex that contains CYTOCHROME B GROUP; CYTOCHROME C1; and iron-sulfur centers. It catalyzes the oxidation of ubiquinol to UBIQUINONE, and transfers the electrons to CYTOCHROME C. In MITOCHONDRIA the redox reaction is coupled to the transport of PROTONS across the inner mitochondrial membrane.
Sequence Alignment
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Coenzymes
Small molecules that are required for the catalytic function of ENZYMES. Many VITAMINS are coenzymes.
Optic Atrophy, Hereditary, Leber
A maternally linked genetic disorder that presents in mid-life as acute or subacute central vision loss leading to central scotoma and blindness. The disease has been associated with missense mutations in the mtDNA, in genes for Complex I, III, and IV polypeptides, that can act autonomously or in association with each other to cause the disease. (from Online Mendelian Inheritance in Man, http://www.ncbi.nlm.nih.gov/Omim/, MIM#535000 (April 17, 2001))
Neurospora crassa
Liver
RNA, Messenger
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Estradiol Dehydrogenases
Cell Respiration
The metabolic process of all living cells (animal and plant) in which oxygen is used to provide a source of energy for the cell.
Pyruvates
Pyruvates, in the context of medical and biochemistry definitions, are molecules that result from the final step of glycolysis, containing a carboxylic acid group and an aldehyde group, playing a crucial role in cellular metabolism, including being converted into Acetyl-CoA to enter the Krebs cycle or lactate under anaerobic conditions.
Succinate-Semialdehyde Dehydrogenase
An enzyme that plays a role in the GLUTAMATE and butanoate metabolism pathways by catalyzing the oxidation of succinate semialdehyde to SUCCINATE using NAD+ as a coenzyme. Deficiency of this enzyme, causes 4-hydroxybutyricaciduria, a rare inborn error in the metabolism of the neurotransmitter 4-aminobutyric acid (GABA).
Chemical Precipitation
Electrons
Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.
Oxidoreductases Acting on CH-CH Group Donors
Electron Transport Complex II
A flavoprotein oxidase complex that contains iron-sulfur centers. It catalyzes the oxidation of SUCCINATE to fumarate and couples the reaction to the reduction of UBIQUINONE to ubiquinol.
Mitochondria, Muscle
Mitochondria of skeletal and smooth muscle. It does not include myocardial mitochondria for which MITOCHONDRIA, HEART is available.
RNA, Guide
Small kinetoplastid mitochondrial RNA that plays a major role in RNA EDITING. These molecules form perfect hybrids with edited mRNA sequences and possess nucleotide sequences at their 5'-ends that are complementary to the sequences of the mRNA's immediately downstream of the pre-edited regions.
Sequence Analysis, DNA
Sequence Homology, Nucleic Acid
Proton Pumps
Integral membrane proteins that transport protons across a membrane. This transport can be linked to the hydrolysis of ADENOSINE TRIPHOSPHATE. What is referred to as proton pump inhibitors frequently is about POTASSIUM HYDROGEN ATPASE.
Plastoquinone
Polyunsaturated side-chain quinone derivative which is an important link in the electron transport chain of green plants during the photosynthetic conversion of light energy by photophosphorylation into the potential energy of chemical bonds.
Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)
Leigh Disease
A group of metabolic disorders primarily of infancy characterized by the subacute onset of psychomotor retardation, hypotonia, ataxia, weakness, vision loss, eye movement abnormalities, seizures, dysphagia, and lactic acidosis. Pathological features include spongy degeneration of the neuropile of the basal ganglia, thalamus, brain stem, and spinal cord. Patterns of inheritance include X-linked recessive, autosomal recessive, and mitochondrial. Leigh disease has been associated with mutations in genes for the PYRUVATE DEHYDROGENASE COMPLEX; CYTOCHROME-C OXIDASE; ATP synthase subunit 6; and subunits of mitochondrial complex I. (From Menkes, Textbook of Child Neurology, 5th ed, p850).
Quinones
Ketoglutaric Acids
Nitrate Reductase (NADH)
An NAD-dependent enzyme that catalyzes the oxidation of nitrite to nitrate. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM and is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. It was formerly classified as EC 1.6.6.1.
Intracellular Membranes
Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
Uncoupling Agents
Adenosine Triphosphate
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
Acetaldehyde
Open Reading Frames
Prephenate Dehydrogenase
An enzyme that catalyzes the conversion of prephenate to p-hydroxyphenylpyruvate in the presence of NAD. In the enteric bacteria, this enzyme also possesses chorismate mutase activity, thereby catalyzing the first two steps in the biosynthesis of tyrosine. EC 1.3.1.12.
DNA Primers
Vitamin K
A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: VITAMIN K 1 (phytomenadione) derived from plants, VITAMIN K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, VITAMIN K 3 (menadione). Vitamin K 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin K. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin K.
Energy Metabolism
1-Pyrroline-5-Carboxylate Dehydrogenase
An enzyme that catalyzes the oxidation of 1-pyrroline-5-carboxylate to L-GLUTAMATE in the presence of NAD. Defects in the enzyme are the cause of hyperprolinemia II.
Solanum tuberosum
Cytochrome b Group
Gene Expression Regulation, Bacterial
Mutagenesis, Insertional
Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.
Genome, Mitochondrial
The genetic complement of MITOCHONDRIA as represented in their DNA.
Spectrophotometry
Oxidoreductases Acting on CH-NH Group Donors
Polymerase Chain Reaction
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Transcription, Genetic
Saccharomyces cerevisiae
1-Methyl-4-phenylpyridinium
An active neurotoxic metabolite of 1-METHYL-4-PHENYL-1,2,3,6-TETRAHYDROPYRIDINE. The compound reduces dopamine levels, inhibits the biosynthesis of catecholamines, depletes cardiac norepinephrine and inactivates tyrosine hydroxylase. These and other toxic effects lead to cessation of oxidative phosphorylation, ATP depletion, and cell death. The compound, which is related to PARAQUAT, has also been used as an herbicide.
Hydrogen Peroxide
Sulfur
Glutaryl-CoA Dehydrogenase
A flavoprotein enzyme that is responsible for the catabolism of LYSINE; HYDROXYLYSINE; and TRYPTOPHAN. It catalyzes the oxidation of GLUTARYL-CoA to crotonoyl-CoA using FAD as a cofactor. Glutaric aciduria type I is an inborn error of metabolism due to the deficiency of glutaryl-CoA dehydrogenase.
Cell Membrane
Electron Transport Chain Complex Proteins
A complex of enzymes and PROTON PUMPS located on the inner membrane of the MITOCHONDRIA and in bacterial membranes. The protein complex provides energy in the form of an electrochemical gradient, which may be used by either MITOCHONDRIAL PROTON-TRANSLOCATING ATPASES or BACTERIAL PROTON-TRANSLOCATING ATPASES.
Chromatography, Ion Exchange
Superoxides
Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.
Saccharopine Dehydrogenases
Amine oxidoreductases that use either NAD+ (EC 1.5.1.7) or NADP+ (EC 1.5.1.8) as an acceptor to form L-LYSINE or NAD+ (EC 1.5.1.9) or NADP+ (EC 1.5.1.10) as an acceptor to form L-GLUTAMATE. Deficiency of this enzyme causes HYPERLYSINEMIAS.
Restriction Mapping
RNA Editing
A process that changes the nucleotide sequence of mRNA from that of the DNA template encoding it. Some major classes of RNA editing are as follows: 1, the conversion of cytosine to uracil in mRNA; 2, the addition of variable number of guanines at pre-determined sites; and 3, the addition and deletion of uracils, templated by guide-RNAs (RNA, GUIDE).
Protein Conformation
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Operon
Plants
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
20-alpha-Hydroxysteroid Dehydrogenase
Citric Acid Cycle
A series of oxidative reactions in the breakdown of acetyl units derived from GLUCOSE; FATTY ACIDS; or AMINO ACIDS by means of tricarboxylic acid intermediates. The end products are CARBON DIOXIDE, water, and energy in the form of phosphate bonds.
Protein Subunits
Reactive Oxygen Species
Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.