The Role of Tetrahydrobiopterin in Aromatic Amino Acid Hydroxylases

1 The Role of Tetrahydrobiopterin in Aromatic Amino Acid Hydroxylases 

Most aromatic hydroxylases aue either cytochrome- or flavin-dependent enzymes the three enzymes that catadyze hydroxylation of the anomatic amino acids phenylalanine, tyrosine, amd tryptophaui ane apparently unique in 

Utilizing tetreihydrobiopterin, which acts as a reducing substrate rather them a coenzyme. They are monooxygenases one atom of oxygen is incorporated into the substrate as a hydroxyl group, and the other is reduced to water. 

The SEune pool of tetreihydrobiopterin and the same dihydrobiopterin re-ducteise are involved in the central nervous system in the hydroxylation of edl three aromatic amino acids. Cleissical phenylketonuria, which involves a defect 

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