GAAentsyymi

GAAentsyymi, also known as gamma-aminobutyric acid transaminase (GABA-T), is a key enzyme in the metabolism of gamma-aminobutyric acid (GABA). GABA is the primary inhibitory neurotransmitter in the mammalian central nervous system. GAAentsyymi catalyzes the irreversible transfer of an amino group from GABA to alpha-ketoglutarate, forming succinic semialdehyde and glutamate. This reaction is essential for regulating GABA levels in the brain.

The enzyme is found in both the cytosol and mitochondria of neurons and glial cells. In the mitochondria, the product succinic semialdehyde can be further metabolized by succinic semialdehyde dehydrogenase, linking GABA metabolism to the citric acid cycle. In the cytosol, succinic semialdehyde can be converted to gamma-hydroxybutyrate (GHB), another neuroactive compound.

Inhibition of GAAentsyymi leads to increased GABA levels, which can have anticonvulsant and anxiolytic effects. Drugs that inhibit GAAentsyymi have been developed as antiepileptic medications, such as vigabatrin and tiagabine, although tiagabine acts by inhibiting GABA reuptake rather than GAAentsyymi directly. Genetic variations or dysfunction of GAAentsyymi have been associated with certain neurological disorders, including epilepsy and intellectual disability. Research continues to explore the role of GAAentsyymi in various neurological conditions and its potential as a therapeutic target.