Target type: molecularfunction
Catalysis of the reaction: protein L-glutamine + H2O = protein L-glutamate + NH3. [EC:3.5.1.44, MetaCyc:CHEBDEAMID-RXN]
Protein-glutamine γ-glutaminase activity is a critical enzymatic function involved in the hydrolysis of glutamine, a non-essential amino acid, to glutamate and ammonia. This reaction is essential for numerous cellular processes, including:
- **Nitrogen Metabolism:** Glutaminase serves as a key enzyme in the catabolism of glutamine, providing ammonia for the urea cycle, which is crucial for detoxification of ammonia.
- **Glutamate Synthesis:** The glutamate produced by glutaminase is a vital precursor for neurotransmitter synthesis and other metabolic pathways.
- **Acid-Base Balance:** Glutaminase activity contributes to acid-base balance by releasing ammonia, which can be used to buffer excess acid.
- **Cellular Signaling:** Glutamine metabolism and its modulation by glutaminase activity are increasingly recognized as playing a role in cellular signaling pathways, particularly in the regulation of cell growth and proliferation.
- **Energy Metabolism:** Glutamine is a major source of energy for cells, and its breakdown by glutaminase provides glutamate and ammonia, which can be further utilized in metabolic pathways.
The specific molecular function of glutaminase involves the cleavage of the γ-amide bond of glutamine, releasing glutamate and ammonia. This reaction requires a water molecule and is catalyzed by the enzyme's active site, which often contains a catalytic triad composed of a lysine, a histidine, and a glutamate residue.
The enzyme's activity is tightly regulated, being influenced by factors such as substrate availability, allosteric regulation, and post-translational modifications.
Overall, protein-glutamine γ-glutaminase activity is a fundamental enzymatic process that is essential for a wide range of cellular functions, particularly in nitrogen metabolism, glutamate synthesis, and energy production.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Protein-glutamine gamma-glutamyltransferase 2 | A protein-glutamine gamma-glutamyltransferase 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P21980] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 1-(2-naphthalenyl)-3-[(phenylmethyl)-propan-2-ylamino]-1-propanone | ZM39923: structure in first source | naphthalenes | |
| beta-lapachone | beta-lapachone : A benzochromenone that is 3,4-dihydro-2H-benzo[h]chromene-5,6-dione substituted by geminal methyl groups at position 2. Isolated from Tabebuia avellanedae, it exhibits antineoplastic and anti-inflammatory activities. beta-lapachone: antineoplastic inhibitor of reverse transcriptase, DNA topoisomerase, and DNA polymerase | benzochromenone; orthoquinones | anti-inflammatory agent; antineoplastic agent; plant metabolite |
| vitamin k 3 | Vitamin K 3: A synthetic naphthoquinone without the isoprenoid side chain and biological activity, but can be converted to active vitamin K2, menaquinone, after alkylation in vivo. | 1,4-naphthoquinones; vitamin K | angiogenesis inhibitor; antineoplastic agent; EC 3.4.22.69 (SARS coronavirus main proteinase) inhibitor; human urinary metabolite; nutraceutical |
| 5-bromoisatin | indoles | anticoronaviral agent | |
| isatin | tribulin: endogenous MONOAMINE OXIDASE inhibitory activity extractable into ethyl acetate found in brain and many mammalian tissues and fluids; ISATIN is a major component; produced in excess following alcohol withdrawal; | indoledione | EC 1.4.3.4 (monoamine oxidase) inhibitor; plant metabolite |
| indirubin | |||
| 5-Chloro-1H-indole-2,3-dione | indoles | anticoronaviral agent | |
| 5-iodoisatin | 5-iodoisatin: structure in first source | indoles | anticoronaviral agent |
| isoindigotin | isoindigotin: used in treatment of chronic granulocytic leukemia; structure given in first source | ||
| n-phenylacrylamide | N-phenylacrylamide: structure in first source | ||
| nsc 95397 | 1,4-naphthoquinones | ||
| ag-213 | tyrphostin 47: inhibits protein-tyrosine kinase activity of EGF-R both in vitro and in living cells; | ||
| rottlerin | rottlerin : A chromenol that is 2,2-dimethyl-2H-chromene substituted by hydroxy groups at positions 5 and 7, a 3-acetyl-2,4,6-trihydroxy-5-methylbenzyl group at position 6 and a (1E)-3-oxo-1-phenylprop-1-en-3-yl group at position 8. A potassium channel opener, it is isolated from Mallotus philippensis. rottlerin: an angiogenesis inhibitor; an inhibitor of protein kinase Cdelta (PKCdelta) and calmodulin kinase III; RN refers to (E)-isomer; do not confuse this chalcone with an anthraquinone that is also called rottlerin (RN 481-72-1); | aromatic ketone; benzenetriol; chromenol; enone; methyl ketone | anti-allergic agent; antihypertensive agent; antineoplastic agent; apoptosis inducer; K-ATP channel agonist; metabolite |
| gw-5074 | |||
| glutaminase | |||
| guanylyl imidodiphosphate | guanosine 5'-[beta,gamma-imido]triphosphate : A nucleoside triphosphate analogue that is GTP in which the oxygen atom bridging the beta- to the gamma- phosphate is replaced by a nitrogen atom A non-hydrolyzable analog of GTP, it binds tightly to G-protein in the presence of Mg(2+). Guanylyl Imidodiphosphate: A non-hydrolyzable analog of GTP, in which the oxygen atom bridging the beta to the gamma phosphate is replaced by a nitrogen atom. It binds tightly to G-protein in the presence of Mg2+. The nucleotide is a potent stimulator of ADENYLYL CYCLASES. | nucleoside triphosphate analogue |