Phenylalanine metabolism

Phenylalanine metabolism refers to the series of biochemical reactions responsible for processing the essential amino acid L-phenylalanine after dietary intake. In humans, this process primarily involves conversion of L-phenylalanine into L-tyrosine via phenylalanine hydroxylase, using tetrahydrobiopterin as a cofactor. Tyrosines are then further metabolized into catecholamines like dopamine and epigenetic intermediates. Disruption at any step—most notably due to genetic deficiency in phenylethananline hydroxlylase, causes accumulation of toxic metabolites leading most commonly to phenyketonuria (PKU)—a treatable but serious neurodevelopmental disorder if left unmanaged. Management strategies include lifelong dietary restriction and/or pharmacologic enhancement or bypassing defective enzymatic steps.[1][3][5]

Other names

Phenylalanine and tyrosine metabolismPhe metabolism

For drugs acting on this pathway: - Sapropterin acts as a synthetic cofactor to enhance residual activity of mutant phenylalanine hydroxylase in PKU patients. - Large neutral amino acids compete with phenylalanine at the blood-brain barrier transporter to reduce its neurotoxic accumulation in the CNS.