Disease relevance of Pdxk

• The pyridoxal phosphate content and the activities of pyridoxine kinase and pyridoxine phosphate oxidase of all Morris hepatomas examined were significantly less than those in adult host or control livers and generally fell in the range determined for fetal and neonatal liver [1].
• Consistently significant differences in enzyme activities between the two groups of animals were found only in pyridoxine kinase indicating that this enzyme plays a key role during the development of vitamin B-6 deficiency [2].
• The activities of pyridoxal kinase in the basal ganglion (3.84 +/- 0.23 vs. 4.99 +/- 0.11 microgram pyridoxal phosphate/mg protein/15 min) and in the cerebral cortex (3.40 +/- 0.06 vs. 3.70 +/- 0.04 microgram pyridoxal phosphate/mg protein/15 min) were lower in seizure-prone rats than in seizure-resistant rats [3].

High impact information on Pdxk

• Human pyridoxal kinase. cDNA cloning, expression, and modulation by ligands of the benzodiazepine receptor [4].
• Transcripts of the pyridoxal kinase gene were detectable in all human tissues examined, and were particularly abundant in the testes [4].
• They exhibit no pyridoxal kinase activity and less than 5% of the pyridoxamine-P(pyridoxine-P) oxidase activity in cytosol and cannot synthesize pyridoxal-P or pyridoxamine-P from pyridoxine, pyridoxal, or pyridoxine-P [5].
• Effects of epsilon-pyridoxyllysine and related compounds on liver and brain pyridoxal kinase and liver pyridoxamine (pyridoxine) 5'-phosphate oxidase [6].
• Effect of tryptophan metabolites on the activities of rat liver pyridoxal kinase and pyridoxamine 5-phosphate oxidase in vitro [7].

Chemical compound and disease context of Pdxk

• Effects of vitamin B-6 deficiency and 4'- deoxypyridoxine on pyridoxal phosphate concentrations, pyridoxine kinase and other aspects of metabolism in the rat [8].

Biological context of Pdxk

• In light of the suggestion that phosphorylation and binding to proteins serve to prevent the diffusion of B-6 vitamers out of cells, the differential response of pyridoxine kinase activity in liver and brain may be important in the maintenance of the vitamin B-6 supply in the central nervous system [2].

Anatomical context of Pdxk

• The growth inhibitory effects of these analogues on cells in culture correlated well with their effects on pyridoxal kinase and pyridoxine phosphate oxidase in cell-free systems [9].
• In all groups the pyridoxine kinase activity was highest in the adrenal glands (3.6-6.3 pmole pyridoxine phosphate/minute/mg tissue) followed by the liver (1.3-3.7) and thymus (0.7-1.3) [8].
• The status of vitamin B6 in brains of genetically epilepsy-prone and epilepsy-resistant rats was ascertained by measuring the concentrations of pyridoxal phosphate and the activities of pyridoxal kinase in the hippocampus, basal ganglia, cerebellum, and cerebral cortex, as well as in the entire brain [3].
• Tat-mediated protein transduction of human brain pyridoxal kinase into PC12 cells [10].
• Levodopa-mediated alteration in the activity of pyridoxal kinase in rat basal ganglia [11].

Associations of Pdxk with chemical compounds

• The 4-vinyl anatogue of pyridoxal was shown to be a substrate of pyridoxal kinase and the product a potent inhibitor of pyridoxine oxidase, competing with pyridoxal phosphate [9].
• Among the tryptophan metabolites, picolinate, xanthurenate, quinolinate, tryptamine and 5-hydroxytryptamine inhibited pyridoxal kinase [7].
• Effect of contraceptive steroids on gamma-aminobutyric acid metabolism and pyridoxal kinase activity in rat brain [12].
• Progesterone treatment resulted in a significantly lower PK activity in the kidney of the treated rats than in untreated controls [13].
• We have developed an assay for pyridoxal kinase which takes advantage of the intense fluorescence yield of the oxime of pyridoxal or pyridoxal-5'-phosphate and the substantial difference in the rates of formation of these two oximes [14].

Other interactions of Pdxk

• The specific activity level of pyridoxal kinase decreased 3.2 times and that of pyridoxine 5'-phosphate oxidase increased 1.5 times in the state of deficiency [15].
• At physiological concentrations, zinc stimulates the activity of pyridoxal kinase, enhancing the formation of pyridoxal phosphate, which in turn enhances the activity of glutamic acid decarboxylase [16].

Analytical, diagnostic and therapeutic context of Pdxk

• Rapid purification by affinity chromatography of rat brain pyridoxal kinase and pyridoxamine-5-phosphate oxidase [17].
• The chronic oral administration of 100 mg/kg/day of levodopa did not alter the concentration of pyridoxal phosphate, but increased the activity of pyridoxal kinase in 7 days [11].

References