In enzymology, 4-aminobutyrate transaminase (EC 18.104.22.168), also called GABA transaminase or 4-aminobutyrate aminotransferase, is an enzyme that catalyzes the chemical reaction:
- 4-aminobutanoate + 2-oxoglutarate succinate semialdehyde + L-glutamate
Thus, the two substrates of this enzyme are 4-aminobutanoate (GABA) and 2-oxoglutarate. The two products are succinate semialdehyde and L-glutamate.
This enzyme belongs to the family of transferases, specifically the transaminases, which transfer nitrogenous groups. The systematic name of this enzyme class is 4-aminobutanoate:2-oxoglutarate aminotransferase. This enzyme participates in 5 metabolic pathways: alanine and aspartate metabolism, glutamate metabolism, beta-alanine metabolism, propanoate metabolism, and butanoate metabolism. It employs one cofactor, pyridoxal phosphate.
As of late 2007, 9 structures have been solved for this class of enzymes, with PDB accession codes 1OHV, 1OHW, 1OHY, 1SF2, 1SFF, 1SZK, 1SZS, 1SZU, and 2EO5.
- ^ Awad R, Muhammad A, Durst T, Trudeau VL, Arnason JT (August 2009). "Bioassay-guided fractionation of lemon balm (Melissa officinalis L.) using an in vitro measure of GABA transaminase activity". Phytotherapy Research. 23 (8): 1075–81. doi:10.1002/ptr.2712. PMID 19165747.