Distribution of 4a‐hydroxytetrahydropterin dehydratase in rat tissues Comparison with the aromatic amino acid hydroxylases

FEBS Letters

Kaufman, Seymour¹  Milstien, Sheldon¹  Davis, Michael D.¹ 

[1] Laboratory of Neurochemistry, National Institute of Mental Health, Bethesda, MD 20892, USA

关键词: Phenylalanine;    Hyperphenylalaninemia;    Tetrahydrobiopterin;    7-Biopterin;    Phenylalanine hydroxylase;    4a-Carbinolamine dehydratase;    4a-Hydroxy tetrahydrobiopterin;    BH4;    6-[dihydroxypropyl-(l-erythro)-5;    6;    7;    8-tetrahydropterin (tetrahydrobiopterin);    BH3OH;    4a-hyd oxytetrahydrobiopterin (4a-carbinolamine);   

DOI  :  10.1016/0014-5793(92)80288-R

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A 4a-carbinolamine intermediate is generated stoichiometrically during the tetrahydrobiopterin-dependent phenylalanine hydroxylation reaction catalyzed by phenylalanine hydroxylase. The dehydration of the carbinolamine is catalyzed by the enzyme, 4a-hydroxytetrahydropterin dehydratase. We have now examined the distribution of the dehydratase activity in various rat tissues by activity measurements and by immunoblot analysis to explore the possibility that the dehydratase may also play a role in tyrosine and tryptophan hydroxylation. The only two tissues that express relatively high dehydratase activity are liver and kidney, which are also the only two tissues that express phenylalanine hydroxylase activity. The dehydratase activity was generally very low in those tissues which contain high levels of tyrosine and tryptophan hydroxylase activity, except for the pineal gland. These results suggest that the dehydratase may not play an important role in the regulation of the synthesis of those neurotransmitters which are derived from the hydroxylated aromatic amino acids.

【 授权许可】

Unknown