PDX3 and SALT OVERLY SENSITIVE4 (SOS4), encoding pyridoxine/pyridoxamine 5#-phosphate oxidase and pyridoxal kinase, respectively, are the only known genes involved in the salvage pathway of pyridoxal 5#-phosphate in plants. In this study, we determined the phenotype, stress responses, vitamer levels, and regulation of the vitamin B6 pathway genes in Arabidopsis (Arabidopsis thaliana) plants mut...

Vitamin Be has for some time been implicated in protein metabolism. More recently a specific function of pyridoxal in the coenzome of tyrosine decarboxylase has been found (l), and the discovery of this function extended to include amino acid decarboxylases in general (2, 3). All members of the vitamin Be group (pyridoxine, pyridoxal,” pyridoxamine) are converted into this coenzyme (termed code...

BACKGROUND There is a need for a reliable and accurate method for quantification of each of the seven individual vitamin B(6) compounds including pyridoxine-β-glucoside in foods. OBJECTIVE To determine pyridoxal (PL), pyridoxamine (PM), pyridoxine (PN), pyridoxal 5'-phosphate (PLP), pyridoxamine 5'-phosphate (PMP), pyridoxine 5'-phosphate (PNP), and pyridoxine-β-glucoside (PNG) in foods. DE...

PURPOSE Senile cataracts are associated with oxidation, fragmentation, cross-linking, insolubilization, and yellow pigmentation of lens crystallins. This process is partially explained by advanced glycation end products (AGEs) from ascorbic acid (ASA), as the authors unequivocally demonstrated in an hSVCT2 transgenic mouse. The authors present the first pharmacologic intervention study against ...

The specificity and active site properties of vitamin B6 phosphatase purified from human erythrocytes were studied by kinetic analyses with vitamin B6 compounds and derivatives and chemical modification with group-specific reagents. The kinetic constants for pyridoxal phosphate (PLP), 4-pyridoxic acid phosphate, pyridoxine phosphate, and pyridoxamine phosphate were determined from pH 5 to 9. Th...

Conditions for reductive methylation of amine groups in proteins using formaldehyde and cyanoborohydride can be chosen to modify selectively the active site lysyl residue of aspartate aminotransferase among the 19 lysyl residues in each subunit of this protein. Apoenzyme must be treated, under mildly acidic conditions (pH = 6), at a relatively low molar ratio of formaldehyde to protein (40:1); ...

The first naturally occurring form of vitamin B6 was isolated in 1938. It has the structure, confirmed by chemical synthesis (1939), of 3-hydroxy-4,5-bis(hydroxymethyl)-2-methylpyridine (I; R = -CHzOH). The trivial name “pyridoxine,” proposed for this compound by P. GyGrgy, came into general use as a synonym for “vitamin Be.” Two other natural compounds possessing vitamin B6 activity, detected ...

Cycloserine (CS, 4-amino-3-isoxazolidone) is a cyclic amino acid mimic that is known to inhibit many essential pyridoxal 5'-phosphate (PLP)-dependent enzymes. Two CS enantiomers are known; D-cycloserine (DCS, also known as Seromycin) is a natural product that is used to treat resistant Mycobacterium tuberculosis infections as well as neurological disorders since it is a potent NMDA receptor ago...