» Articles » PMID: 29569907

Design and Mechanism of GABA Aminotransferase Inactivators. Treatments for Epilepsies and Addictions

Overview
Journal Chem Rev
Specialty Chemistry
Date 2018 Mar 24
PMID 29569907
Citations 30
Authors
Affiliations
Soon will be listed here.
Abstract

When the brain concentration of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) diminishes below a threshold level, the excess neuronal excitation can lead to convulsions. This imbalance in neurotransmission can be corrected by inhibition of the enzyme γ-aminobutyric acid aminotransferase (GABA-AT), which catalyzes the conversion of GABA to the excitatory neurotransmitter l-glutamic acid. It also has been found that raising GABA levels can antagonize the rapid elevation and release of dopamine in the nucleus accumbens, which is responsible for the reward response in addiction. Therefore, the design of new inhibitors of GABA-AT, which increases brain GABA levels, is an important approach to new treatments for epilepsy and addiction. This review summarizes findings over the last 40 or so years of mechanism-based inactivators (unreactive compounds that require the target enzyme to catalyze their conversion to the inactivating species, which inactivate the enzyme prior to their release) of GABA-AT with emphasis on their catalytic mechanisms of inactivation, presented according to organic chemical mechanism, with minimal pharmacology, except where important for activity in epilepsy and addiction. Patents, abstracts, and conference proceedings are not covered in this review. The inactivation mechanisms described here can be applied to the inactivations of a wide variety of unrelated enzymes.

Citing Articles

L. aqueous extract protects mice against pilocarpine-picrotoxin kindling-induced temporal lobe epilepsy, oxidative stress, and alteration in GABAergic/cholinergic pathways and BDNF expression.

Mambou H, Pale S, Bopda O, Jugha V, Musa N, Ojongnkpot T Front Pharmacol. 2025; 15:1301002.

PMID: 39996118 PMC: 11848678. DOI: 10.3389/fphar.2024.1301002.


Suppressing astrocytic GABA transaminase enhances tonic inhibition and weakens hippocampal spatial memory.

Park M, Lim J, Kim D, Lee W, Yoon B, Lee C Exp Mol Med. 2025; 57(2):379-389.

PMID: 39894826 PMC: 11873293. DOI: 10.1038/s12276-025-01398-0.


Low-frequency stimulation of corpus callosum suppresses epileptiform activity in the cortex through γ-aminobutyric acid type B receptor and slow afterhyperpolarization-mediated reduction in tissue excitability.

Pakalapati N, Chiang C, Durand D Epilepsia. 2024; 65(12):3689-3702.

PMID: 39425912 PMC: 11647442. DOI: 10.1111/epi.18135.


New epilepsy therapies in development.

Klein P, Kaminski R, Koepp M, Loscher W Nat Rev Drug Discov. 2024; 23(9):682-708.

PMID: 39039153 DOI: 10.1038/s41573-024-00981-w.


Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies.

Jiao D, Xu L, Gu Z, Yan H, Shen D, Gu X Neural Regen Res. 2024; 20(4):917-935.

PMID: 38989927 PMC: 11438347. DOI: 10.4103/NRR.NRR-D-23-01444.


References
1.
Kobayashi K, Miyazawa S, Endo A . Isolation and inhibitory activity of gabaculine, a new potent inhibitor of gamma-aminobutyrate aminotransferase produced by a Streptomyces. FEBS Lett. 1977; 76(2):207-10. DOI: 10.1016/0014-5793(77)80153-1. View

2.
Ravasz D, Kacso G, Fodor V, Horvath K, Adam-Vizi V, Chinopoulos C . Catabolism of GABA, succinic semialdehyde or gamma-hydroxybutyrate through the GABA shunt impair mitochondrial substrate-level phosphorylation. Neurochem Int. 2017; 109:41-53. DOI: 10.1016/j.neuint.2017.03.008. View

3.
Jung M, Heydt J, Casara P . Gamma-allenyl GABA, a new inhibitor of 4-amino butyrate amino transferase. Comparison with other inhibitors of this enzyme. Biochem Pharmacol. 1984; 33(22):3717-20. DOI: 10.1016/0006-2952(84)90164-3. View

4.
Mehta P, Hale T, Christen P . Aminotransferases: demonstration of homology and division into evolutionary subgroups. Eur J Biochem. 1993; 214(2):549-61. DOI: 10.1111/j.1432-1033.1993.tb17953.x. View

5.
Huang H, Hah J, Silverman R . Mechanism of nitric oxide synthase. Evidence that direct hydrogen atom abstraction from the O-H bond of NG-hydroxyarginine is not relevant to the mechanism. J Am Chem Soc. 2001; 123(11):2674-6. DOI: 10.1021/ja005900u. View