Which vitamin functions as a cofactor for transaminase?

Pyridoxine, also known as vitamin B6, functions as a cofactor for transaminase enzymes, which are crucial in amino acid metabolism. Transaminases, such as alanine transaminase (ALT) and aspartate transaminase (AST), facilitate the transfer of amino groups between amino acids and alpha-keto acids, a process that is essential in the synthesis and breakdown of amino acids. Pyridoxine acts specifically as a coenzyme for this reaction, enabling the proper functioning of these enzymes.

This vitamin is involved in numerous metabolic pathways, including neurotransmitter synthesis and the metabolism of carbohydrates and lipids. The active form of pyridoxine, pyridoxal phosphate, is integral for the transaminase reaction, as it forms a transient Schiff base with the amino acid substrate, allowing the transfer of the amino group to occur.

In contrast, other options like riboflavin, thiamine, and folate do have vital roles in metabolism but do not directly participate as cofactors for transaminases. Riboflavin is primarily involved in energy production as a component of the flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). Thiam