Vitamin B6-dependent decarboxylase (PLP-dependent decarboxylase)

The Vitamin B6-dependent decarboxylase and related enzymes group refers to a superfamily of enzymes, primarily Group II decarboxylases, that utilize pyridoxal 5'-phosphate (PLP) as an essential cofactor to catalyze the removal of carbon dioxide from amino acids (UniProt, 2023). This family encompasses several high-value therapeutic targets, most notably aromatic L-amino acid decarboxylase (AADC), which is responsible for the final step in the synthesis of dopamine and serotonin (NCBI Gene, 2024). Other members include glutamate decarboxylase (GAD), involved in GABA production, and ornithine decarboxylase (ODC), a rate-limiting enzyme in polyamine synthesis (PubMed, 2022). Pharmacological intervention typically involves the use of small-molecule inhibitors to modulate neurotransmitter levels or arrest cell proliferation; for instance, carbidopa is used to inhibit peripheral AADC in Parkinson's disease, while eflornithine targets ODC to treat parasitic infections and certain malignancies (StatPearls, 2023; DrugBank, 2024). Because this term describes a broad class of enzymes with diverse substrates and physiological roles, drug specificity is a major challenge, and systemic inhibition can lead to significant side effects related to neurotransmitter depletion or metabolic disruption (NIH GARD, 2023).

Other names

Group II decarboxylaseAmino acid decarboxylasePLP-dependent decarboxylase familyAromatic L-amino acid decarboxylaseGlutamate decarboxylaseHistidine decarboxylaseOrnithine decarboxylase

Inhibition of the decarboxylation reaction through competitive binding at the active site or irreversible inactivation of the pyridoxal 5'-phosphate (PLP) cofactor.