RT Journal Article
SR Electronic
T1 Tyrosine hydroxylase: studies on the phosphorylation of a purified preparation of the brain enzyme by the cyclic AMP-dependent protein kinase.
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 647
OP 653
VO 216
IS 3
A1 A M Edelman
A1 J D Raese
A1 M A Lazar
A1 J D Barchas
YR 1981
UL http://jpet.aspetjournals.org/content/216/3/647.abstract
AB Tyrosine hydroxylase [L-tyrosine, tetrahydropteridine: oxygen oxidoreductase (3-hydroxylating); EC 1.14.16.2](TH) was purified from bovine corpus striatum. The purification involved sequential DEAE cellulose, hydroxylapatite and CM Sephadex C-50 chromatography, followed by glycerol density gradient centrifugation. Final preparations appeared to be 90 to 100% pure as judged by polyacrylamide gel electrophoresis under denaturing conditions in acetic acid-urea. The enzyme was estimated to have a minimum molecular weight of approximately 60,000 daltons. Purified TH could be activated in vitro by incubation with magnesium adenosine triphosphate and the catalytic subunit of cyclic AMP-dependent protein kinase (ATP/protein phosphotransferase; EC 2.7.1.37). When the final purified preparation of TH was incubated under these conditions utilizing [gamma-32P]ATP, it was found to incorporate 0.7 to 0.9 mol of phosphorus/mol of protein. These results suggest that the activation of TH in the presence of phosphorylating conditions is due to its phosphorylation by cyclic AMP-dependent protein kinase.