Aromatic-amino-acid aminotransferase (ArAT) (ArAT)

Aromatic-amino-acid aminotransferase (ArAT), also known as aromatic-amino-acid transaminase (EC 2.6.1.57), is a pyridoxal phosphate (PLP)-dependent enzyme that plays a central role in the metabolism of aromatic amino acids, including phenylalanine, tyrosine, and tryptophan [1, 2, 3]. It catalyzes the reversible transfer of an amino group from an aromatic amino acid to an alpha-keto acid, such as 2-oxoglutarate, to form the corresponding aromatic oxo-acid and glutamate [2, 4, 8]. This enzyme is widely distributed across bacteria, fungi, and plants, where it is involved in diverse pathways such as the kynurenine pathway, methionine salvage, and the biosynthesis of secondary metabolites like alkaloids and indoles [11, 13, 35]. In the context of human health, ArAT is a significant therapeutic target for infectious diseases, particularly tuberculosis, as it is essential for the survival and pathogenesis of Mycobacterium tuberculosis [16, 18, 19]. Furthermore, microbial ArATs in the gut microbiota have emerged as targets for modulating the bioavailability of drugs like L-DOPA in Parkinson's disease and for regulating the production of immunomodulatory indole derivatives that act as aryl hydrocarbon receptor (AhR) ligands [7, 12, 17, 31]. While specific drugs targeting ArAT are primarily in the research and development stage, competitive inhibitors and broad-spectrum PLP-dependent enzyme inhibitors like aminooxyacetic acid are commonly used to study its function and therapeutic potential [24, 25, 30].

Other names

Aromatic-amino-acid transaminaseAromatic aminotransferaseAroATEC 2.6.1.57Aromatic-amino-acid:2-oxoglutarate aminotransferaseTyrosine aminotransferase (microbial)Kynurenine aminotransferase (microbial)

Competitive inhibition of the pyridoxal phosphate (PLP)-dependent transamination reaction, preventing the conversion of aromatic amino acids to their corresponding alpha-keto acids.