phenylalanine hydroxylase
(PAH) phen·yl·al·a·nine hy·drox·y·lase (PAH) (fen″əl-alґə-nēn hi-drokґsə-lās) a monooxygenase that activates molecular oxygen to catalyze the oxidation of phenylalanine to tyrosine, activating oxygen via oxidation of the cofactor tetrahydrobiopterin to dihydrobiopterin. Deficiency of the enzyme results in hyperphenylalaninemia, with the most severe manifestation being phenylketonuria. In official nomenclature, called phenylalanine 4-monooxygenase [EC 1.14.16.1].
Medical dictionary.
2011.