Pyridoxal phosphate produces an instantaneous drop in the rate of DNA synthesis and strongly inhibits RNase H and DNA polymerase [1]. Pyridoxal phosphate binding totally inhibits NEIL2. Pyridoxal phosphate-polymerized NEIL2 displayed fold reduced activity than the intact enzyme over a wide variety of enzyme/substrate interactions. Following conjugation with pyridoxal phosphate, NEIL2 loses its capacity to bind THF ligand [2].

[1]. Modak MJ. Pyridoxal 5' phosphate: a selective inhibitor of oncornaviral DNA polymerases. Biochem Biophys Res Commun. 1976 Jul 12;71(1):180-7.

[2]. Inactivation of NEIL2 DNA glycosylase by pyridoxal phosphate reveals a loop important for substrate binding. Biochem Biophys Res Commun. 2010 Mar 26;394(1):100-5.

Pyridoxal 5'-phosphate is the monophosphate ester obtained by condensation of phosphoric acid with the primary hydroxy group of pyridoxal. It has a role as a coenzyme, a human metabolite, an Escherichia coli metabolite, a Saccharomyces cerevisiae metabolite, a mouse metabolite, an EC 2.7.7.7 (DNA-directed DNA polymerase) inhibitor and a cofactor. It is a vitamin B6 phosphate, a member of methylpyridines, a monohydroxypyridine and a pyridinecarbaldehyde. It is functionally related to a pyridoxal. It is a conjugate acid of a pyridoxal 5'-phosphate(2-).
This is the active form of vitamin B6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (pyridoxamine).
Medicure's MC-1 drug is a cardio-protectant, designed to reduce the damage to the heart when arteries are blocked and when they are subsequently reopened after bypass surgery.
Pyridoxal 5'-phosphate is a metabolite found in or produced by Escherichia coli (strain K12, MG1655).
Pyridoxal phosphate has been reported in Arabidopsis thaliana, Homo sapiens, and other organisms with data available.
Pyridoxal Phosphate is the active form of vitamin B6 and a coenzyme for many pyridoxal phosphate (PLP)-dependent enzymes. PLP is involved in numerous enzymatic transamination, decarboxylation and deamination reactions; it is necessary for the synthesis of amino acids and amino acid metabolites, and for the synthesis and/or catabolism of certain neurotransmitters, including the conversion of glutamate into gamma-aminobutyric acid (GABA) and levodopa into dopamine. PLP can be used as a dietary supplement in cases of vitamin B6 deficiency. Reduced levels of PLP in the brain can cause neurological dysfunction.
Pyridoxal 5'-phosphate is a metabolite found in or produced by Saccharomyces cerevisiae.
This is the active form of VITAMIN B 6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (PYRIDOXAMINE).
See also: Pyridoxal (annotation moved to).

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Drug Indication
For nutritional supplementation and for treating dietary shortage or imbalance.
Investigated for use/treatment in coronary artery disease.

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Mechanism of Action
Pyridoxal Phosphate is a coenzyme of many enzymatic reactions. It is the active form of vitamin B6 which comprises three natural organic compounds, pyridoxal, pyridoxamine and pyridoxine. Pyridoxal phosphate acts as a coenzyme in all transamination reactions, and in some oxylation and deamination reactions of amino acids. The aldehyde group of pyridoxal phosphate forms a Schiff-base linkage with the epsilon-amino group of a specific lysine group of the aminotransferase enzyme. The alpha-amino group of the amino acid substrate displaces the epsilon-amino group of the active-site lysine residue. The resulting aldimine becomes deprotonated to become a quinoid intermediate, which in turn accepts a proton at a different position to become a ketimine. Ketimine becomes hydrolyzed so that the amino group remains on the protein complex.
MC-1 is a biologically active natural product which can be regarded as a chemical entity that has been evolutionarily selected and validated for binding to particular protein domains. Thus, its underlying structural architecture, or scaffold, has already been biologically established as safe and active, providing a powerful guiding principle for novel drug and library development.

C8H10NO6P

247.14

247.024

54-47-7

Pyridoxal phosphate-d5;1246818-16-5

1051

Off-white to yellow solid powder

1.6±0.1 g/cm3

565.7±60.0 °C at 760 mmHg

140-143ºC

296.0±32.9 °C

0.0±1.6 mmHg at 25°C

1.641

-0.52

3

7

4

16

292

0

NGVDGCNFYWLIFO-UHFFFAOYSA-N

InChI=1S/C8H10NO6P/c1-5-8(11)7(3-10)6(2-9-5)4-15-16(12,13)14/h2-3,11H,4H2,1H3,(H2,12,13,14)

(4-formyl-5-hydroxy-6-methylpyridin-3-yl)methyl dihydrogen phosphate

MC 1; MC1; MC-1

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~62.5 mg/mL (~252.89 mM)
H2O : ~5 mg/mL (~20.23 mM)

Solubility in Formulation 1: 2 mg/mL (8.09 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication (<60°C).

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 (Please use freshly prepared in vivo formulations for optimal results.)