All articles starting with G
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Glutamate dehydrogenase
Glutamate dehydrogenase (GDH, GLUD1) is a hexameric enzyme catalyzing reversible glutamate-to-α-ketoglutarate deamination with NAD(P)+; allosterically regulated in animals (ADP/leucine activate, GTP inhibits) and linked to hyperinsulinism-hyperammonemia syndrome.
Glutamate racemase
Glutamate racemase (MurI, RacE, EC 5.1.1.3) is a cofactor-independent bacterial enzyme converting L-glutamate to D-glutamate for peptidoglycan cell wall synthesis, using two conserved cysteines; essential and an antibacterial drug target.
Glutamate receptor
Glutamate receptor (GluR), ionotropic (AMPA, kainate, NMDA, GluD) and metabotropic families, receptors for glutamate, the brain's main excitatory neurotransmitter; 18 iGluR genes, tetrameric channels, central to synaptic plasticity and neuropsychiatric disease.
Glutamate Synthase
Glutamate synthase (GOGAT, glutamine 2-oxoglutarate aminotransferase) is an iron-sulfur flavoenzyme making two glutamates from glutamine and 2-oxoglutarate; with GS it forms the GS/GOGAT cycle, the main ammonia-assimilation route in bacteria and plants.
Glutamate--cysteine ligase
Glutamate--cysteine ligase (GCL, EC 6.3.2.2; formerly γ-glutamylcysteine synthetase) is the ATP- and magnesium-dependent heterodimeric enzyme (GCLC + GCLM subunits) catalyzing the rate-limiting first step of glutathione synthesis, forming γ-glutamylcysteine from glutamate and cysteine.
Glutamate-cysteine ligase catalytic subunit
GCLC (glutamate-cysteine ligase catalytic subunit, also GCS, GLCLC) is the 73 kDa catalytic subunit of the rate-limiting enzyme of glutathione synthesis, paired with the GCLM modifier subunit; its gene sits at 6p12.1.
Glutamate-cysteine ligase deficiency
Glutamate-cysteine ligase deficiency (gamma-glutamylcysteine synthetase deficiency, OMIM 230450) is an ultra-rare autosomal recessive glutathione-synthesis disorder causing hemolytic anemia, sometimes with neuropathy, myopathy, or spinocerebellar degeneration.
Glutamic acid
Glutamic acid (L-glutamate) is a proteinogenic amino acid with an acidic side chain; as glutamate it is the brain's principal excitatory neurotransmitter and the source of umami taste.
Glutaminase
Glutaminase (GLS/GLS2; EC 3.5.1.2) is a mitochondrial enzyme hydrolyzing glutamine to glutamate and ammonium, central to renal ammoniagenesis, hepatic ureagenesis, and glutamine-addicted cancer; its inhibitor telaglenastat (CB-839) reached phase II trials.
Glutamine
Glutamine (symbol Gln) is a polar, proteinogenic amino acid and the amide of glutamic acid, the principal carrier of nitrogen in cells and the most abundant free amino acid.
Glutamine (amino acid)
Glutamine (L-glutamine, abbreviated Gln or Q) is a nonessential amino acid and the body's most abundant free amino acid, serving as its principal nitrogen carrier between organs.
Glutamine amidotransferase
Glutamine amidotransferases (GATs, GATase domains) are two-domain enzymes that hydrolyze glutamine to glutamate and channel ammonia 10–40 Å to a synthase domain, supplying nitrogen for nucleotides, amino acids, amino sugars, coenzymes, and antibiotics; class I uses a Cys-His-Glu triad, class II an N-terminal cysteine of the Ntn-hydrolase fold.
Glutamine Synthetase
Glutamine synthetase (EC 6.3.1.2, L-glutamate:ammonia ligase) is the ATP-dependent enzyme assimilating ammonium into glutamine; types GSI, GSII, GSIII predate LUCA and it anchors nitrogen metabolism in bacteria, plants, and brain.
Glutamine-tRNA synthetase
Glutaminyl-tRNA synthetase (GlnRS, EC 6.1.1.18), a class I aminoacyl-tRNA synthetase, charges tRNA^Gln with glutamine via a glutaminyl-adenylate intermediate; absent from most bacteria and all archaea, which use a transamidation pathway.
Glutamyl-tRNA reductase
Glutamyl-tRNA reductase (GluTR) is an NADPH-dependent oxidoreductase that reduces tRNA-bound glutamate to glutamate-1-semialdehyde, the first committed and rate-limiting step of tetrapyrrole biosynthesis in plants, algae, and some bacteria.
Glutamyl-tRNA synthetase
Glutamyl-tRNA synthetase (GluRS) is a class I aminoacyl-tRNA synthetase that attaches glutamate to tRNA during protein synthesis. Some non-discriminating forms also charge tRNA^Gln, feeding the ancient transamidation pathway.
Glutaraldehyde
Glutaraldehyde, also known as glutaral or pentanedial, is a five-carbon dialdehyde, a colorless oily liquid used as a high-level disinfectant, chemical sterilant, and protein cross-linking reagent.
Glutaredoxin
Glutaredoxin (Grx), also called thioltransferase, is a small glutathione-dependent thiol oxidoreductase of the thioredoxin fold superfamily, discovered by Arne Holmgren in 1976 in E. coli; it reduces ribonucleotide reductase, catalyzes protein deglutathionylation, and binds iron-sulfur clusters.
Glutaredoxin-1
Glutaredoxin-1 (Grx1, GLRX) is the human cytosolic dithiol glutaredoxin, a thioredoxin-superfamily enzyme with a CPYC active site that catalyzes deglutathionylation of S-glutathionylated proteins in a GSH-, glutathione reductase-, and NADPH-dependent system.
Glutaredoxin-2
Glutaredoxin-2 (Grx2, GLRX2), a vertebrate mitochondrial dithiol glutaredoxin on chromosome 1q31.2 with CSYC active site, catalyzes deglutathionylation, binds a regulatory 2Fe-2S cluster, and links to cardiac and metabolic disease.
Glutaric Acid
Glutaric acid, also called pentanedioic acid, is a five-carbon dicarboxylic acid with formula C5H8O4, produced as a by-product of adipic acid manufacture and used in polymers.
Glutaric acidemia type 3
Glutaric acidemia type 3 (GA3, OMIM 231690), an autosomal recessive SUGCT (C7orf10) deficiency causing isolated urinary glutaric acid elevation with no consistent clinical phenotype, considered a probable non-disease.
Glutaryl-CoA dehydrogenase
Glutaryl-CoA dehydrogenase (GCDH, EC 1.3.8.6) is a mitochondrial FAD-dependent homotetrameric enzyme catalyzing glutaryl-CoA to crotonyl-CoA in lysine and tryptophan breakdown; deficiency causes glutaric aciduria type 1.
Glutaryl-CoA dehydrogenase deficiency
Glutaryl-CoA dehydrogenase deficiency, also called glutaric acidemia type 1 or glutaric aciduria type 1, is an autosomal recessive neurometabolic disorder impairing lysine and tryptophan breakdown, affecting about 1 in 100,000 newborns worldwide.
Glutathione (γ-L-glutamyl-L-cysteinyl-glycine)
Glutathione (GSH, γ-L-glutamyl-L-cysteinyl-glycine) is the most abundant intracellular low-molecular-weight thiol, a tripeptide of glutamate, cysteine, and glycine serving as antioxidant, detoxifier, and redox biomarker; oral bioavailability is limited.
Glutathione conjugation
Glutathione conjugation, also called GSH conjugation or mercapturic acid pathway step one, is a phase II metabolism reaction where glutathione S-transferases attach GSH to electrophilic xenobiotics, usually detoxifying them but sometimes bioactivating them.
Glutathione peroxidase
Glutathione peroxidase (GPx, EC 1.11.1.9), a selenium-containing antioxidant enzyme family (GPx1–GPx8) discovered in 1957, reduces hydrogen peroxide and lipid hydroperoxides using glutathione; GPx1 was the first mammalian selenoprotein.
Glutathione reductase
Glutathione reductase (GR, GSR, EC 1.8.1.7) is a dimeric FAD flavoprotein that uses NADPH to reduce glutathione disulfide to GSH, central to redox homeostasis in plants, animals, and microbes.
Glutathione S-transferase
Glutathione S-transferase (GST), EC 2.5.1.18: enzyme family detoxifying electrophiles by conjugating glutathione; cytosolic, mitochondrial, and MAPEG families; GSTM1 null in half of humans; GSTP1 variants affect chemotherapy response.
Glutathione synthase
Glutathione synthase (glutathione synthetase, GSS, EC 6.3.2.3) is the homodimeric ATP-grasp enzyme catalyzing the second, ATP-dependent step of glutathione synthesis, adding glycine to γ-glutamylcysteine; GSS mutations cause rare autosomal recessive glutathione synthetase deficiency.