Vitamin B3 (niacin), NAD and NADP biosynthesis pathway (Zea mays) ..
Vitamins and Aging: Pathways to NAD + Synthesis
Analysis of MDRS subscales revealed significantly better performance by NADH subjects on measures of verbal fluency, visual-constructional ability and a trend to better performance on a measure of abstract verbal reasoning.
ACMS can also be diverted away from NAD + synthesis, ..
Uridylyltransferase is activated by -ketoglutarateand ATP, while it is inhibited by glutamine and Pi.The following diagram summarizes the regulation of bacterial glutaminesynthetase (see text page 1035) : We can "walk through" this regulatory cascade by looking at aspecific example, namely increased levels of -ketoglutarate( reflecting a corresponding increase in NH3) levels: (1) Uridylyltransferase activity is increased (2) PII (in complex with adenylyltransferase)is uridylylated (3) Glutamine synthetase is deadenylylated (4) -ketoglutarate and NH3 form glutamine and Pi That the control of bacterial glutamine synthetase is exquisitely sensitiveto the level of the cell's nitrogen metabolites is illustrated by the fact thatthe glutamine just produced in the above cascade is now an inhibitor of furtherglutamine production. Proline, Ornithine and Arginine are derived from GlutamateThe first step involves phosphorylation of glutamate by ATP with the enzyme -glutamylkinase, followed by reduction to glutamate-5-semialdehyde which spontaneouslycyclizes (no enzyme required) to an internal Schiff base. The formation ofthe semialdehyde also requires the presence of either NADP or NADPH.The semialdehyde is a branch point, however.
Nicotinamide adenine dinucleotide phosphate - Wikipedia
N2 - The chemical synthesis of 4-phenoxybenzamide adenine dinucleotide (3), a NAD analogue which mimics isoniazid-NAD adduct and inhibits Mycobacterium tuberculosis NAD-dependent enoyl-ACP reductase (InhA), is reported. The 4-phenoxy benzamide riboside (1) has been prepared as a key intermediate, converted into its 5′-mononucleotide (2), and coupled with AMP imidazolide to give the desired NAD analogue 3. It inhibits InhA with IC50 = 27 μM.
Nicotinamide adenine dinucleoti…
AB - Purpose: Attempts to selectively initiate tumor cell death through inducible apoptotic pathways are increasingly being exploited as a potential anticancer strategy. Inhibition of NAD+ synthesis by a novel agent FK866 has been recently reported to induce apoptosis in human leukemia, hepatocarcinoma cells in vitro, and various types of tumor xenografts in vivo. In the present study, we used 1H-decoupled phosphorus ( 31P) magnetic resonance spectroscopy (MRS) to examine the metabolic changes associated with FK866 induced tumor cell death in a mouse mammary carcinoma. Experimental Design: Induction of apoptosis in FK866-treated tumors was confirmed by histology and cytofluorometric analysis. FK866-induced changes in mammary carcinoma tumor metabolism in vivo were investigated using 1H-decoupled 31P MRS. To discern further the changes in metabolic profiles of tumors observed in vivo, high-resolution in vitro 1H-decoupled 31P MRS studies were carried out with perchloric acid extracts of mammary carcinoma tumors excised after similar treatments. In addition, the effects of FK866 on mammary carcinoma tumor growth and radiation sensitivity were studied. Results: Treatment with FK866 induced a tumor growth delay and enhanced radiation sensitivity in mammary carcinoma tumors that was associated with significant increases in the 31P MR signal in the phosphomonoester region and a decrease in NAD+ levels, pH, and bioenergetic status. The 31P MRS of perchloric acid extracts of treated tumors identified the large unresolved signal in the phosphomonoester region as the resultant of resonances originating from intermediates of tumor glycolysis and guanylate synthesis in addition to alterations in pyridine nucleotide pools and phospholipid metabolism. Conclusion: The present results suggest that FK866 interferes with multiple biochemical pathways that contribute to the increased cell death (apoptosis) and subsequent radiation sensitivity observed in the mammary carcinoma that could be serially monitored by 31P MRS.