Biology:4-aminobutyrate—pyruvate transaminase

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Short description: Class of enzymes
4-aminobutyrate---pyruvate transaminase
Identifiers
EC number2.6.1.96
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum

4-aminobutyrate---pyruvate transaminase (EC 2.6.1.96, aminobutyrate aminotransferase, gamma-aminobutyrate aminotransaminase, gamma-aminobutyrate transaminase, gamma-aminobutyric acid aminotransferase, gamma-aminobutyric acid pyruvate transaminase, gamma-aminobutyric acid transaminase, gamma-aminobutyric transaminase, 4-aminobutyrate aminotransferase, 4-aminobutyric acid aminotransferase, aminobutyrate transaminase, GABA aminotransferase, GABA transaminase, GABA transferase, POP2 (gene)) is an enzyme with systematic name 4-aminobutanoate:pyruvate aminotransferase.[1][2][3][4] This enzyme is a type of GABA transaminase, which degrades the neurotransmitter GABA. The enzyme catalyses the following chemical reaction

(1) 4-aminobutanoate + pyruvate [math]\displaystyle{ \rightleftharpoons }[/math] succinate semialdehyde + L-alanine
(2) 4-aminobutanoate + glyoxylate [math]\displaystyle{ \rightleftharpoons }[/math] succinate semialdehyde + glycine

This enzyme requires pyridoxal 5'-phosphate.

Clinical significance

Phenylethylidenehydrazine, the active metabolite of phenelzine, inhibits gamma-aminobutyric acid transaminase and subsequently increases GABA concentrations in the central nervous system. This may contribute to the notable anxiolytic effects of phenelzine.[5]

References

  1. Van Cauwenberghe, O.R.; Shelp, B.J. (1999). "Biochemical characterization of partially purified gaba:pyruvate transaminase from Nicotiana tabacum". Phytochemistry 52: 575–581. doi:10.1016/s0031-9422(99)00301-5. 
  2. "Pollen tube growth and guidance is regulated by POP2, an Arabidopsis gene that controls GABA levels". Cell 114 (1): 47–59. July 2003. doi:10.1016/s0092-8674(03)00479-3. PMID 12859897. 
  3. "Biochemical characterization, mitochondrial localization, expression, and potential functions for an Arabidopsis gamma-aminobutyrate transaminase that utilizes both pyruvate and glyoxylate". Journal of Experimental Botany 60 (6): 1743–57. 2009. doi:10.1093/jxb/erp044. PMID 19264755. 
  4. "Subcellular localization and expression of multiple tomato gamma-aminobutyrate transaminases that utilize both pyruvate and glyoxylate". Journal of Experimental Botany 60 (11): 3255–67. 2009. doi:10.1093/jxb/erp161. PMID 19470656. 
  5. "Chronic administration of the antidepressant phenelzine and its N-acetyl analogue: effects on GABAergic function". Journal of Neural Transmission. Supplementum 41: 115–22. 1994. doi:10.1007/978-3-7091-9324-2_15. ISBN 978-3-211-82521-1. PMID 7931216. 

External links