title: ATP, cyclic AMP, and magnesium increase the affinity of rat striatal tyrosine hydroxylase for its cofactor.
abstract: Treatment of rat striatal tyrosine hydroxylase [tyrosine 3-monooxygenase; L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating); EC 1.14.16.2] with conditions optimal for protein phosphorylation results in the reduction of the tyrosine hydroxylase Km for the cofactor 6-methyltetrahydropterin from 0.50 mM to 0.16 mM. This reaction is dependent upon ATP, 3':5'-cAMP, and Mg++ and causes a marked decrease in the sensitivity to end-product inhibition. Other brain regions and the adrenal gland show a similar response.
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000311:Adrenal Glands / Q000201:enzymology; D000818:Animals; D001708:Biopterins / Q000031:analogs & derivatives; D001921:Brain / Q000201:enzymology; D003342:Corpus Striatum / Q000201:enzymology*; D000242:Cyclic AMP / Q000494:pharmacology*; D004298:Dopamine / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology*; D008297:Male; D009928:Organ Specificity; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism; D051381:Rats; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*
chemical_list: D001708:Biopterins; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D014446:Tyrosine 3-Monooxygenase; D011494:Protein Kinases; D008274:Magnesium; D004298:Dopamine