Herein, we describe a novel enzymatic cycling method to measure nicotinamide mononucleotide (NMN) or nicotinic acid mononucleotide (NaMN), which are precursors of NAD biosynthesis. A gene encoding an NMN adenylyltransferase (NMNAT, EC 2.7.7.1) homologue was identified in Thermus thermophilus HB8. The gene from T. thermophilus (TtNMNAT) was engineered for expression in Escherichia coli and the recombinant enzyme found to be stable, retaining full activity after incubation for 45 min at 70°C. The K values for NMN and ATP were calculated to be 0.263 and 1.27 mM, respectively, with a V value of 60.3 μmoL/min/mg. TtNMNAT was successfully applied to the colorimetric NMN or NaMN assays, which employed (i) adenylation of NMN to NAD by TtNMNAT or adenylation of NaMN to deamido-NAD (NaAD) by TtNMNAT followed by amidation of NaAD to NAD by NAD synthetase (NADS, EC 6.3.1.5) and (ii) an NAD cycling reaction using 12α-hydroxysteroid dehydrogenase (12α-HSD, EC 1.1.1.176) and diaphorase (DI, EC 1.6.99.3) to accumulate reduced WST-8. This enzymatic cycling method enabled detection of 0.5 μM (12.2 nM in the reaction mixture) NMN or NaMN in an automatic clinical analyzer.
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http://dx.doi.org/10.1016/j.jbiosc.2017.10.017 | DOI Listing |
Front Microbiol
December 2024
School of Pharmacy, Binzhou Medical University, Yantai, China.
Nicotinamide mononucleotide (NMN), one of the crucial precursors of nicotinamide adenine dinucleotide, has garnered considerable interest for its pharmacological and anti-aging effects, conferring potential health and economic benefits for humans. Lactic acid bacteria (LAB) are one of the most important probiotics, which is commonly used in the dairy industry. Due to its probiotic properties, it presents an attractive platform for food-grade NMN production.
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 2024
Department of Internal Medicine 1, Shimane University Faculty of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan; The Center for Integrated Kidney Research and Advance, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, 693-8501, Japan. Electronic address:
Inhibition of xanthine oxidoreductase (XOR) was shown to ameliorate the stroke susceptibility in the stroke-prone spontaneously hypertensive rat (SHRSP), suggesting hyperuricemia had a pathological role in this rat model. In this study, we thus aimed to explore mechanisms inducing hyperuricemia in SHRSP. XOR is known to have two forms, xanthine dehydrogenase (XDH) as the prototype and xanthine oxidase (XO) as the converted form through cleavage of a peptide bond or through formation of disulfide bonds in the enzyme.
View Article and Find Full Text PDFNat Metab
December 2024
Department of Biomedicine, University of Bergen, Bergen, Norway.
The coenzyme NAD is consumed by signalling enzymes, including poly-ADP-ribosyltransferases (PARPs) and sirtuins. Ageing is associated with a decrease in cellular NAD levels, but how cells cope with persistently decreased NAD concentrations is unclear. Here, we show that subcellular NAD pools are interconnected, with mitochondria acting as a rheostat to maintain NAD levels upon excessive consumption.
View Article and Find Full Text PDFSubcell Biochem
December 2024
Department of Clinical Molecular Biology, University of Oslo and Akershus University Hospital, Lørenskog, Norway.
Nicotinamide adenine dinucleotide (oxidized form, NAD) serves as a co-substrate and co-enzyme in cells to execute its key roles in cell signalling pathways and energetic metabolism, arbitrating cell survival and death. It was discovered in 1906 by Arthur Harden and William John Young in yeast extract which could accelerate alcohol fermentation. NAD acts as an electron acceptor and cofactor throughout the processes of glycolysis, Tricarboxylic Acid Cycle (TCA), β oxidation, and oxidative phosphorylation (OXPHOS).
View Article and Find Full Text PDFElife
December 2024
Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland.
Aging is marked by a decline in tissue regeneration, posing significant challenges to an increasingly older population. Here, we investigate age-related impairments in calvarial bone healing and introduce a novel two-part rejuvenation strategy to restore youthful repair. We demonstrate that aging negatively impacts the calvarial bone structure and its osteogenic tissues, diminishing osteoprogenitor number and function and severely impairing bone formation.
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