Phenylalanine as substrate for tyrosine hydroxylase in bovine adrenal chromaffin cells.
Incubation of bovine chromaffin cells with L-[14C]phenylalanine resulted in label accumulation in catecholamines at about 30% of the rate seen with L-tyrosine as precursor. Studies with purified tyrosine hydroxylase (EC 1.14.16.2) showed that the enzyme catalysed the hydroxylation of L-phenylalanine first to L-p-tyrosine and then to 3,4-dihydroxyphenylalanine (DOPA). No evidence for a significant involvement of an L-m-tyrosine intermediate in DOPA formation was found.
Fukami
M H
MH
Department of Biochemistry, University of Bergen, Norway.
Haavik
J
J
Flatmark
T
T
D000311:Adrenal Glands / Q000201:enzymology*; D000818:Animals; D002395:Catecholamines / Q000096:biosynthesis; D002417:Cattle; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D006900:Hydroxylation; D010649:Phenylalanine / Q000378:metabolism*; D013379:Substrate Specificity; D014443:Tyrosine / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*
D002395:Catecholamines; D014443:Tyrosine; D010649:Phenylalanine; D004295:Dihydroxyphenylalanine; D014446:Tyrosine 3-Monooxygenase