L-valine transaminase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: 2-oxoglutarate + L-valine = 3-methyl-2-oxobutanoic acid + L-glutamatic acid. [EC:2.6.1.42, MetaCyc:BRANCHED-CHAINAMINOTRANSFERVAL-RXN]

L-valine transaminase activity catalyzes the reversible transfer of an amino group from L-valine to an alpha-keto acid, typically alpha-ketoglutarate. This reaction results in the formation of alpha-ketoisovalerate and L-glutamate. The enzyme is crucial in amino acid metabolism, specifically in the breakdown of branched-chain amino acids (BCAAs) such as valine, leucine, and isoleucine. L-valine transaminase is a pyridoxal phosphate-dependent enzyme, meaning it requires pyridoxal phosphate (PLP) as a cofactor for its activity. PLP, a derivative of vitamin B6, serves as a carrier of amino groups during the transamination reaction. The enzyme first binds L-valine and PLP. The amino group from L-valine is then transferred to the PLP, forming a Schiff base intermediate. Subsequently, the alpha-ketoglutarate binds to the enzyme, and the amino group from the Schiff base is transferred to alpha-ketoglutarate, producing alpha-ketoisovalerate and L-glutamate. This process involves a series of protonation and deprotonation steps, catalyzed by the enzyme, leading to the transfer of the amino group. The enzyme is highly specific for L-valine and alpha-ketoglutarate, ensuring the efficient and regulated breakdown of valine in the metabolic pathway. L-valine transaminase activity plays a significant role in maintaining amino acid homeostasis, providing intermediates for energy production, and contributing to the synthesis of other essential molecules in the body.'
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Proteins (1)

Compounds (1)