PT  - JOURNAL ARTICLE
AU  - Edelman, A M
AU  - Raese, J D
AU  - Lazar, M A
AU  - Barchas, J D
TI  - Tyrosine hydroxylase: studies on the phosphorylation of a purified preparation of the brain enzyme by the cyclic AMP-dependent protein kinase.
DP  - 1981 Mar 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 647--653
VI  - 216
IP  - 3
4099  - http://jpet.aspetjournals.org/content/216/3/647.short
4100  - http://jpet.aspetjournals.org/content/216/3/647.full
SO  - J Pharmacol Exp Ther1981 Mar 01; 216
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.