Page last updated: 2024-10-24

L-cysteine transaminase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: L-cysteine + 2-oxoglutarate = mercaptopyruvate + L-glutamate. [RHEA:17441]

L-cysteine transaminase activity is a biochemical process that catalyzes the transfer of an amino group from L-cysteine to an α-keto acid, typically α-ketoglutarate. This reaction results in the formation of pyruvate and L-glutamate. The enzyme responsible for this activity is called cysteine aminotransferase (CAT), also known as cysteine transaminase.

CAT plays a crucial role in the metabolism of cysteine, a sulfur-containing amino acid essential for various cellular processes. It facilitates the removal of the amino group from L-cysteine, which can then be further metabolized to pyruvate or used in other metabolic pathways.

The reaction mechanism of L-cysteine transaminase activity involves the formation of a Schiff base intermediate between the amino group of L-cysteine and the pyridoxal phosphate (PLP) cofactor bound to the enzyme. This Schiff base is then converted to a quinonoid intermediate, which is subsequently attacked by the α-keto acid, leading to the formation of pyruvate and L-glutamate.

L-cysteine transaminase activity is highly regulated and influenced by various factors, including the availability of substrates, cofactors, and inhibitors. Dysregulation of CAT activity has been linked to several human diseases, including cancer, neurodegenerative disorders, and metabolic diseases. Therefore, understanding the molecular function of L-cysteine transaminase activity is crucial for developing novel therapeutic strategies for these diseases.'
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Proteins (2)

ProteinDefinitionTaxonomy
CDGSH iron-sulfur domain-containing protein 1A CDGSH iron-sulfur domain-containing protein 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9NZ45]Homo sapiens (human)
Aspartate aminotransferase, cytoplasmicAn aspartate aminotransferase, cytoplasmic that is encoded in the genome of human. [PRO:DNx, UniProtKB:P17174]Homo sapiens (human)

Compounds (23)

CompoundDefinitionClassesRoles
4-amino-1,8-naphthalimide4-amino-1,8-naphthalimide: inhibits ADP-ribosylation; sometimes abreviated as 4-AN;benzoisoquinoline;
dicarboximide
tyrphostin ag 1024tyrphostin AG 1024: modulates radiosensitivity in human breast cancer cells; also an IGF1 receptor inhibitoralkylbenzene
carbonyl cyanide m-chlorophenyl hydrazoneCarbonyl Cyanide m-Chlorophenyl Hydrazone: A proton ionophore. It is commonly used as an uncoupling agent and inhibitor of photosynthesis because of its effects on mitochondrial and chloroplast membranes.

CCCP : A member of the class of monochlorobenzenes that is benzene substituted by 2-(1,3-dinitrilopropan-2-ylidene)hydrazinyl and chloro groups at positions 1 and 3, respectively. It is a mitochondrial depolarizing agent that induces reactive oxygen species mediated cell death.
hydrazone;
monochlorobenzenes;
nitrile
antibacterial agent;
geroprotector;
ionophore
furosemidefurosemide : A chlorobenzoic acid that is 4-chlorobenzoic acid substituted by a (furan-2-ylmethyl)amino and a sulfamoyl group at position 2 and 5 respectively. It is a diuretic used in the treatment of congestive heart failure.

Furosemide: A benzoic-sulfonamide-furan. It is a diuretic with fast onset and short duration that is used for EDEMA and chronic RENAL INSUFFICIENCY.
chlorobenzoic acid;
furans;
sulfonamide
environmental contaminant;
loop diuretic;
xenobiotic
gemfibrozilaromatic etherantilipemic drug
glyburideglyburide : An N-sulfonylurea that is acetohexamide in which the acetyl group is replaced by a 2-(5-chloro-2-methoxybenzamido)ethyl group.

Glyburide: An antidiabetic sulfonylurea derivative with actions like those of chlorpropamide
monochlorobenzenes;
N-sulfonylurea
anti-arrhythmia drug;
EC 2.7.1.33 (pantothenate kinase) inhibitor;
EC 3.6.3.49 (channel-conductance-controlling ATPase) inhibitor;
hypoglycemic agent
hydralazinehydralazine : The 1-hydrazino derivative of phthalazine; a direct-acting vasodilator that is used as an antihypertensive agent.

Hydralazine: A direct-acting vasodilator that is used as an antihypertensive agent.
azaarene;
hydrazines;
ortho-fused heteroarene;
phthalazines
antihypertensive agent;
vasodilator agent
pioglitazonepioglitazone : A member of the class of thiazolidenediones that is 1,3-thiazolidine-2,4-dione substituted by a benzyl group at position 5 which in turn is substituted by a 2-(5-ethylpyridin-2-yl)ethoxy group at position 4 of the phenyl ring. It exhibits hypoglycemic activity.

Pioglitazone: A thiazolidinedione and PPAR GAMMA agonist that is used in the treatment of TYPE 2 DIABETES MELLITUS.
aromatic ether;
pyridines;
thiazolidinediones
antidepressant;
cardioprotective agent;
EC 2.7.1.33 (pantothenate kinase) inhibitor;
EC 6.2.1.3 (long-chain-fatty-acid--CoA ligase) inhibitor;
ferroptosis inhibitor;
geroprotector;
hypoglycemic agent;
insulin-sensitizing drug;
PPARgamma agonist;
xenobiotic
hydralazine hydrochloridehydralazine hydrochloride : The hydrochloride salt of hydralazine; a direct-acting vasodilator that is used as an antihypertensive agent.hydrochlorideantihypertensive agent;
vasodilator agent
dihydralazineDihydralazine: 1,4-Dihydrazinophthalazine. An antihypertensive agent with actions and uses similar to those of HYDRALAZINE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p354)phthalazines
ursodeoxycholic acidursodeoxycholate : A bile acid anion that is the conjugate base of ursodeoxycholic acid, obtained by deprotonation of the carboxy group; major species at pH 7.3.

ursodeoxycholic acid : A bile acid found in the bile of bears (Ursidae) as a conjugate with taurine. Used therapeutically, it prevents the synthesis and absorption of cholesterol and can lead to the dissolution of gallstones.

Ursodeoxycholic Acid: An epimer of chenodeoxycholic acid. It is a mammalian bile acid found first in the bear and is apparently either a precursor or a product of chenodeoxycholate. Its administration changes the composition of bile and may dissolve gallstones. It is used as a cholagogue and choleretic.
bile acid;
C24-steroid;
dihydroxy-5beta-cholanic acid
human metabolite;
mouse metabolite
adapaleneadapalene : A naphthoic acid that is CD437 in which the phenolic hydroxy group has been converted to its methyl ether.

Adapalene: A naphthalene derivative that has specificity for RETINOIC ACID RECEPTORS. It is used as a DERMATOLOGIC AGENT for the treatment of ACNE.
adamantanes;
monocarboxylic acid;
naphthoic acid
dermatologic drug;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor;
non-steroidal anti-inflammatory drug
ziprasidoneziprasidone : A piperazine compound having 1,2-benzothiazol-3-yl- and 2-(6-chloro-1,3-dihydro-2-oxindol-5-yl)ethyl substituents attached to the nitrogen atoms.

ziprasidone: a benzisothiazoylpiperazine derivative; has combined dopamine and serotonin receptor antagonist activity; structurally related to tiospirone
1,2-benzisothiazole;
indolones;
organochlorine compound;
piperazines
antipsychotic agent;
dopaminergic antagonist;
histamine antagonist;
muscarinic antagonist;
psychotropic drug;
serotonergic antagonist
rosiglitazoneaminopyridine;
thiazolidinediones
EC 6.2.1.3 (long-chain-fatty-acid--CoA ligase) inhibitor;
ferroptosis inhibitor;
insulin-sensitizing drug
tyrphostin 8tyrphostin 8: a tyrosine kinase inhibitor (a tyrphostin)phenols
aminopyridazineaminopyridazine: structure in first source
curcumincurcumin : A beta-diketone that is methane in which two of the hydrogens are substituted by feruloyl groups. A natural dyestuff found in the root of Curcuma longa.

Curcumin: A yellow-orange dye obtained from tumeric, the powdered root of CURCUMA longa. It is used in the preparation of curcuma paper and the detection of boron. Curcumin appears to possess a spectrum of pharmacological properties, due primarily to its inhibitory effects on metabolic enzymes.
aromatic ether;
beta-diketone;
diarylheptanoid;
enone;
polyphenol
anti-inflammatory agent;
antifungal agent;
antineoplastic agent;
biological pigment;
contraceptive drug;
dye;
EC 1.1.1.205 (IMP dehydrogenase) inhibitor;
EC 1.1.1.21 (aldehyde reductase) inhibitor;
EC 1.1.1.25 (shikimate dehydrogenase) inhibitor;
EC 1.6.5.2 [NAD(P)H dehydrogenase (quinone)] inhibitor;
EC 1.8.1.9 (thioredoxin reductase) inhibitor;
EC 2.7.10.2 (non-specific protein-tyrosine kinase) inhibitor;
EC 3.5.1.98 (histone deacetylase) inhibitor;
flavouring agent;
food colouring;
geroprotector;
hepatoprotective agent;
immunomodulator;
iron chelator;
ligand;
lipoxygenase inhibitor;
metabolite;
neuroprotective agent;
nutraceutical;
radical scavenger
kaempferol7-hydroxyflavonol;
flavonols;
tetrahydroxyflavone
antibacterial agent;
geroprotector;
human blood serum metabolite;
human urinary metabolite;
human xenobiotic metabolite;
plant metabolite
as 605240(5Z)-5-(quinoxalin-6-ylmethylidene)-1,3-thiazolidine-2,4-dione : A quinoxaline derivative that is quinoxaline in which the hydrogen at position 6 is replaced by a (2,4-dioxo-1,3-thiazolidin-5-ylidene)methyl group. It is a potent inhibitor of the PI3Kgamma, with an IC50 of 8 nM and inhibits the progression of joint inflammation and damage in both lymphocyte-independent and dependent mouse models of rheumatoid arthritis.

5-quinoxalin-6-ylmethylenethiazolidine-2,4-dione: a PI3Kgamma inhibitor; structure in first source
quinoxaline derivative;
thiazolidinediones
anti-inflammatory agent;
antirheumatic drug;
EC 2.7.1.137 (phosphatidylinositol 3-kinase) inhibitor
nitrofurantoinnitrofurantoin : An imidazolidine-2,4-dione that is hydantoin substituted at position 1 by a [(5-nitro-2-furyl)methylene]amino group. An antibiotic that damages bacterial DNA.

Nitrofurantoin: A urinary anti-infective agent effective against most gram-positive and gram-negative organisms. Although sulfonamides and antibiotics are usually the agents of choice for urinary tract infections, nitrofurantoin is widely used for prophylaxis and long-term suppression.
imidazolidine-2,4-dione;
nitrofuran antibiotic;
organonitrogen heterocyclic antibiotic;
organooxygen heterocyclic antibiotic
antibacterial drug;
antiinfective agent;
hepatotoxic agent
dantrolene
3-aminopyridine-2-carboxaldehyde thiosemicarbazone3-aminopyridine-2-carboxaldehyde thiosemicarbazone: a neuroprotective agent; structure given in first source
tryprostatin atryprostatin A : A cyclic dipeptide that is brevianamide F (cyclo-L-Trp-L-Pro) substituted at positions 2 and 6 on the indole ring by prenyl and methoxy groups respectively.

tryprostatin A: isolated from Aspergillus fumigatus; a mammalian cell cycle inhibitor; structure given in first source
aromatic ether;
dipeptide;
indole alkaloid;
indoles;
pyrrolopyrazine
breast cancer resistance protein inhibitor