Synthesis Of Nicotinamide Mononucleotide Research Articles

A native phosphoribosyltransferase, PncB, is the key NMN synthase in Bacillus subtilis

Nicotinamide mononucleotide (NMN) is a precursor of NAD+, its efficient bio-production through microbial fermentation has rarely been reported. Bacillus subtilis was postulated to lack the inherent ability of NMN biosynthesis, however, certain level of NMN (53.67 mg/L) was detected in the fermentation broth containing nicotinamide. An endogenous enzyme (PncB) previously annotated as a nicotinic acid phosphotransferase was identified to be involved in the key synthetic reaction, since the deletion of pncB revoked the production of NMN, while the enhanced expression of PncB significantly increased the titer of NMN (110.0 mg/L). The structural simulation of PncB revealed the possible catalytic mechanisms of NMN forming. The NMN synthesis was further boosted by removing a possible deamidase (CinA), the yield of extracellular NMN reached 202.9 mg/L. After introducing the NMN transporter PnuC into the host cell, the fermentation level of NMN increased by another 65.34 %. And, with 20 g/L glucose and 10 g/L NAM supplemented in the medium, a maximal of 1.21 g/L of NMN was accumulated, signifying the potential of biological production of NMN using food-grade Bacillus subtilis.

Harnessing lactic acid bacteria for nicotinamide mononucleotide biosynthesis: a review of strategies and future directions.

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. LAB have also been extensively utilized to enhance the functional properties of pharmaceuticals and cosmetics, making them promising candidates for large-scale up synthesis of NMN. This review provides an in-depth analysis of various metabolic engineering strategies, including enzyme optimization, pathway rewiring, and fermentation process enhancements, to increase NMN yields in LAB. It explores both CRISPR/Cas9 and traditional methods to manipulate key biosynthetic pathways. In particular, this study discussed future research directions, emphasizing the application of synthetic biology, systems biology, and AI-driven optimization to further enhance NMN production. It provides invaluable insights into developing scalable and industrially relevant processes for NMN production to meet the growing market demand.

Synthesis of Nicotinamide Mononucleotide from Xylose via Coupling Engineered Escherichia coli and a Biocatalytic Cascade.

β-Nicotinamide mononucleotide (NMN) has recently gained attention for a nutritional supplement because it is an intermediate in the biosynthesis of nicotinamide adenine dinucleotide (NAD+ ). In this study, we developed NMN synthesis by coupling two modules. The first module is to culture E. coli MG1655 ▵tktA ▵tktB ▵ptsG to metabolize xylose to generate D-ribose in the medium. The supernatant containing D-ribose was applied in the second module which is composed of EcRbsK-EcPRPS-CpNAMPT reaction to synthesize NMN, that requires additional enzymes of CHU0107 and EcPPase to remove feedback inhibitors ADP and pyrophosphate. The second module can be rapidly optimized by comparing NMN production determined by the cyanide assay. Finally, 10 mL optimal biocascade reaction generated NMN with a good yield of 84 % from 1 mM D-ribose supplied from the supernatant of E. coli MG1655 ▵tktA ▵tktB ▵ptsG. Our results can further guide researchers to metabolically engineer E. coli for NMN synthesis.

Biosynthesis of a Therapeutically Important Nicotinamide Mononucleotide through a Phosphoribosyl Pyrophosphate Synthetase 1 and 2 Engineered Strain of Escherichia coli.

Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of nicotinamide with the help of nicotinamide phosphoribosyl transferase (NAMPT) via the salvage pathway. NMN has recently gained great attention as an excellent therapeutic option due to its long-term effective pharmacological activities. In this study, we constructed a recombinant strain of Escherichia coli by inserting NAMPT and phosphoribosyl pyrophosphate synthetase 1 (PRPS1) and PRPS2 (from Homo sapiens) genes to investigate the effect of PRPS1 and PRPS2 on NMN synthesis. The metabolically engineered strain of E. coli BL21 (DE3) exhibited 1.57 mM NMN production in the presence of Mg2+ and phosphates in batch fermentation studies. For further improvement in NMN production levels, effects of different variables were studied using a response surface methodology approach. A significant increment was achieved with a maximum of 2.31 mM NMN production when supplemented with 1% ribose, 1 mM Mg2+ and phosphate, and 0.5% nicotinamide in the presence of a lactose (1%) inducer. Additionally, insertion of the PRPS1 and PRPS2 genes in the phosphoribosyl pyrophosphate synthesis pathway and individual gene expression studies facilitated a higher NMN production at the intracellular level than the reported studies. The strain exhibited intracellular production of NMN from cheap substrates such as glucose, lactose, and nicotinamide. Hence, the overall optimized process can be further scaled up for the economical production of NMN using a recombinant strain of E. coli BL21 (DE3), which is the future perspective of the current study.

Effects of long‐acting somatostatin analogues on adrenal growth and phosphoribosyl pyrophosphate formation in experimental diabetes

Adrenal growth and increased adrenal function occur in experimental diabetes. Previously, we have shown that phosphoribosyl pyrophosphate (PRPP) and PRPP synthetase increased rapidly between 3 and 7 days after induction of diabetes with streptozotocin (STZ), with less marked changes in enzymes of the pentose phosphate pathway. The present study examines the earlier phase of 1-3 days following induction of diabetes, seeking to elucidate whether control of PRPP production is a result of diabetic hyperglycaemia, or to a more general re-ordering of hormonal factors. To investigate this question, the role of insulin and two different long-acting somatostatin analogues, Angiopeptin and Sandostatin, were used in a well-established animal model. PRPP was chosen specifically as a target for these studies in view of its central role in nucleotide formation and nicotinamide mononucleotide synthesis via Nampt which is the rate-limiting step in the synthesis of NAD and which has been shown to have multiple roles in cell signalling in addition to its known function in glycolysis and energy production. Treatment with the somatostatin analogues ab initio effectively abolished the adrenal growth, the increase in PRPP formation and the rise of PRPP synthetase activity in the first 7 days of diabetes, without having any significant effect on blood glucose values. This suggests that elevated glucose per se is not responsible for the diabetic adrenal hypertrophy and implies that growth factors/hormones, regulated by somatostatin analogues, play a significant role in adrenal growth processes.

NMNAT suppresses Tau-induced neurodegeneration by promoting clearance of hyperphosphorylated Tau oligomers in a Drosophila model of tauopathy

Tauopathies, including Alzheimer's disease, are a group of neurodegenerative diseases characterized by abnormal tau hyperphosphorylation that leads to formation of neurofibrillary tangles. Drosophila models of tauopathy display prominent features of the human disease including compromised lifespan, impairments of learning, memory and locomotor functions and age-dependent neurodegeneration visible as vacuolization. Here, we use a Drosophila model of frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), in order to study the neuroprotective capacity of a recently identified neuronal maintenance factor, nicotinamide mononucleotide (NAD) adenylyl transferase (NMNAT), a protein that has both NAD synthase and chaperone function. NMNAT is essential for maintaining neuronal integrity under normal conditions and has been shown to protect against several neurodegenerative conditions. However, its protective role in tauopathy has not been examined. Here, we show that overexpression of NMNAT significantly suppresses both behavioral and morphological deficits associated with tauopathy by means of reducing the levels of hyperphosphorylated tau oligomers. Importantly, the protective activity of NMNAT protein is independent of its NAD synthesis activity, indicating a role for direct protein-protein interaction. Next, we show that NMNAT interacts with phosphorylated tau in vivo and promotes the ubiquitination and clearance of toxic tau species. Consequently, apoptosis activation was significantly reduced in brains overexpressing NMNAT, and neurodegeneration was suppressed. Our report on the molecular basis of NMNAT-mediated neuroprotection in tauopathies opens future investigation of this factor in other protein foldopathies.

Age Difference in Nicotinamide Mononucleotide Synthesis by Human Erythrocytes

IT is well known that human erythrocytes contain an active enzyme system capable of synthesizing considerable amounts of nicotinamide mononucleotide from nicotinamide added in vitro 1. The nicotinamide mononucleotide synthetase is very specific for human erythrocytes as the only other mammal in the blood cells of which it could be detected is the guinea pig2. It was found here, however, that the activity of the given synthetase in human erythrocytes can be shown at the beginning of the fifth month of life when its activity rapidly reaches almost a maximum level, remaining then practically without change. Whereas mammalian erythrocytes not synthesizing nicotinamide mononucleotide are characterized by a high content of pyridine nucleotides, their amount being several times higher than in human and guinea pig erythrocytes2, the non-synthesizing child erythrocytes contain even somewhat less pyridine nucleotides than those of adult humans.

Species difference in pyridine nucleotide synthesis by erythrocytes.

Leder and Handler1 have described the synthesis of pyridine nucleotide from nicotinamide and glucose by human erythrocyte homolysates in amounts as much as ten times the normal content and they identified the synthesized material as nicotinamide mononucleotide. These authors also suggested that fructose diphosphate and adenosine triphosphate were required for optimal synthesis of nicotinamide mononucleotide. While synthesis of pyridine nucleotide is thus known to occur in vitro by washed human erythrocytes, its presence and its synthesis in other mammalian species have not yet been examined.

SYNTHESIS OF NICOTINAMIDE MONONUCLEOTIDE BY HUMAN ERYTHROCYTES IN VITRO

SYNTHESIS OF NICOTINAMIDE MONONUCLEOTIDE BY HUMAN ERYTHROCYTES IN VITRO