title: Effect of pyridoxal 5-phosphate on carbidopa and decarboxylation of levodopa.
abstract: To study the interaction between enzymes and coenzymes and carbidopa and levodopa, a paired-ion high-pressure liquid chromatographic method was developed to separate carbidopa, dopamine, levodopa, and pyridoxal 5-phosphate. Carbidopa strongly reacted with pyridoxal 5-phosphate, contrary to a previous report. Tyrosine decarboxylase and tyrosine decarboxylase apoenzyme had some activity against levodopa, which could be increased by adding pyridoxal 5-phosphate to the mixture. This activity was inhibited by hydroxylamine hydrochloride.
mesh_terms: D001051:Apoenzymes / Q000494:pharmacology; D002230:Carbidopa / Q000378:metabolism*; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D003653:Decarboxylation; D006898:Hydroxylamines / Q000494:pharmacology; D007980:Levodopa / Q000378:metabolism*; D011732:Pyridoxal Phosphate / Q000494:pharmacology*; D014445:Tyrosine Decarboxylase / Q000494:pharmacology
chemical_list: D001051:Apoenzymes; D006898:Hydroxylamines; D007980:Levodopa; D011732:Pyridoxal Phosphate; D014445:Tyrosine Decarboxylase; D002230:Carbidopa