pH‐dependent release of catecholamines from tyrosine hydroxylase and the effect of phosphorylation of Ser‐40

FEBS Letters

Haavik, J.¹  Fiatmark, T.¹  Martinez, A.¹ 

[1] Department of Biochemistry, University of Bergen, N-5009 Bergen, Norway

关键词: Tyrosine hydroxylase;    Phosphorylation;    cyclic AMP;    Catecholamine;    Adrenaline;    Noradrenaline;    TH;    tyrosine hydroxylase;    NA;    noradrenaline;   

DOI  :  10.1016/0014-5793(90)80230-G

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Bovine adrenal tyrosine hydroxylase (TH) is isolated in a partially inhibited state with the feed-back inhibitors adrenaline and noradrenaline tightly coordinated to high-spin (S = ) Fe(III) at the active site. In addition to the charge-transfer interaction with iron, an additional charged group in the polypeptide chain, with an apparent pK _a of about 5.3 at 4°C, is involved in the binding of catecholamines. Protonation of this group increases the pseudo-first order rate constant for the dissociation of the TH-[³H]noradrenaline complex more than 100-fold at 4°C. At pH 7.0 and 30°C, phosphorylation of Ser-40 causes a 6-fold increase in the rate constant for this dissociation.

【 授权许可】

Unknown