Activity of pyridoxamine as a substrate for brain pyridoxal kinase.
The substrate activity of pyridoxamine (PM) for brain pyridoxal (PL) kinase was examined in view of a recent report which indicated that PM was a poor substrate for this enzyme. Bovine brain PL kinase was shown by liquid chromatography to catalyze the phosphorylation of PM (Km = 65 microM). The identity of the reaction product, pyridoxamine 5'-phosphate, was confirmed by is ability to act as a substrate for liver pyridoxine (pyridoxamine) 5'-phosphate oxidase. The results, which indicate that PM is a good substrate for brain PL kinase, are consistent with the proposed role of intracellular phosphorylation in the uptake of vitamin B-6 brain tissue.
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D007700:Kinetics; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D011731:Pyridoxal Kinase / Q000378:metabolism*; D011733:Pyridoxamine / Q000378:metabolism*; D013379:Substrate Specificity
D011733:Pyridoxamine; D010770:Phosphotransferases; D011731:Pyridoxal Kinase