Hydroxylation of Tryptophan by Phenylalanine Hydroxylase

Hydroxylation of tryptophan by phenylalanine hydroxylase.

The biosynthesis of serotonin (5-hydroxytryptamine) involves, as a preliminary step, the hydroxylation of L-tryptophan to 5hydroxytryptophan, followed by decarboxylation of the 5-hydroxytryptophan formed (1). The second reaction has been demonstrated to occur in many tissues, and the enzyme responsible has been extensively studied (2). Two recent reports on the hydroxylation of tryptophan repre...

Phenylalanine Hydroxylase, Tyrosine Hydroxylase, and Tryptophan Hydroxylase

Tetrahydropterin oxidation without hydroxylation catalyzed by rat liver phenylalanine hydroxylase.

Stabilization of tryptophan hydroxylase 2 by l‐phenylalanine‐induced dimerization

Tryptophan hydroxylase 2 (TPH2) catalyses the initial and rate-limiting step in the biosynthesis of serotonin, which is associated with a variety of disorders such as depression, obsessive compulsive disorder, and schizophrenia. Full-length TPH2 is poorly characterized due to low purification quantities caused by its inherent instability. Three truncated variants of human TPH2 (rch TPH2; regula...

The hydroxylation of phenylalanine and tyrosine by tyrosine hydroxylase from cultured pheochromocytoma cells.

Pheochromocytoma tyrosine hydroxylase was reported to have unusual catalytic properties, which might be unique to the tumor enzyme (Dix, T. A., Kuhn, D. M., and Benkovic, S. J. (1987) Biochemistry 24, 3354-3361). Two such properties, namely the apparent inability to hydroxylate phenylalanine and an unprecedented reactivity with hydrogen peroxide were investigated further in the present study. T...