á-Nicotinamide Adenine Dinucleotide, 500mg (C08-0504-726)

This is an ultrapure NAD, chromatographically purified to remove trace inhibitors. β-NAD, a pyridine nucleotide and biologically active form of nicotinic acid, is a coenzyme necessary for the catalytic reaction of certain enzymes. It occurs in living cells primarily in the oxidized state. Serves as a coenzyme of the dehydrogenases, especially in the dehydrogenation of primary and secondary alcohols. NAD usually acts as a hydrogen acceptor, forming NADH which then serves as a hydrogen donor in the respiratory chain. Applications Many metabolites and enzymes of biological interest are present in tissues at low concentrations. With the use of β-NAD as a catalyst intermediate and several enzymes in a multistep system, known as enzyme cycling, much greater sensitivity for detection of these components is achieved. The reduced form, β-NADH, is fluorescent whereas β-NAD is not. This difference in fluorescence provides a sensitive fluorescent measurement of the oxidized or reduced pyridine nucleotides at concentrations down to 10- 7 M. Biochem/physiol Actions Electron acceptor. β-NAD is a carrier for hydride ion, forming b-NADH. Hydride ion is enzymatically removed from a substrate molecule by the action of dehydrogenases such as malic dehydrogenase and lactic dehydrogenase. Such enzymes catalyze the reversible transfer of a hydride ion from malate or lactate to b-NAD to form the reduced product, b-NADH. Unlike b-NAD which has no absorbance at 340 nm, b-NADH absorbs at 340 nm (EmM = 6.22). The increase in absorbance at 340 nm with the formation of b-NADH is the basis for measurement of activity of many enzymes. Synonyms: β-DPN, NAD, Nadide, β-NAD, Diphosphopyridine nucleotide, DPN, Coenzyme 1, Cozymase, Nadide, Adenosine 5'-(trihydrogen diphosphate) P'->5'-ester with 3-(aminocarbonyl)-1-β-D-ribofuranosylpyridinium inner salt, 3-carbamoyl-1-β-D-ribofuranosylpyridinium hydroxide 5'->5'- ester with adenosine 5'-(trihydrogen pyrophosphate) inner salt CAS Number: 53-84-9 Molecular Formula: C₂₁H₂₇N₇O₁₄P₂·x H₂O Molecular Weight: 663.4 (anhyd.) EC Number: 200-184-4 MDL Number: MFCD00036253