scholarly journals New Chemical Probe Targeting Bacterial NAD Kinase

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4893
Author(s):  
David A. Clément ◽  
Clarisse Leseigneur ◽  
Muriel Gelin ◽  
Dylan Coelho ◽  
Valérie Huteau ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Kinase Inhibitors ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Infection Model ◽  
Detailed Knowledge ◽  
Nad Kinase ◽  
Chemical Probe ◽  
Covalent Coupling

Nicotinamide adenine dinucleotide (NAD) kinases are essential and ubiquitous enzymes involved in the tight regulation of NAD/nicotinamide adenine dinucleotide phosphate (NADP) levels in many metabolic pathways. Consequently, they represent promising therapeutic targets in cancer and antibacterial treatments. We previously reported diadenosine derivatives as NAD kinase inhibitors with bactericidal activities on Staphylococcus aureus. Among them, one compound (namely NKI1) was found effective in vivo in a mouse infection model. With the aim to gain detailed knowledge about the selectivity and mechanism of action of this lead compound, we planned to develop a chemical probe that could be used in affinity-based chemoproteomic approaches. Here, we describe the first functionalized chemical probe targeting a bacterial NAD kinase. Aminoalkyl functional groups were introduced on NKI1 for further covalent coupling to an activated SepharoseTM matrix. Inhibitory properties of functionalized NKI1 derivatives together with X-ray characterization of their complexes with the NAD kinase led to identify candidate compounds that are amenable to covalent coupling to a matrix.

scholarly journals NAD kinase controls antibiotic susceptibility and pathogenic potential in Staphylococcus aureus

2021 ◽  
Author(s):  
Clarisse Leseigneur ◽  
Laurent Boucontet ◽  
Olivier Gorgette ◽  
Catherine Thouvenot ◽  
Emma Colucci-Guyon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Nicotinamide Adenine Dinucleotide ◽  
Defense Mechanisms ◽  
Antioxidant Properties ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Primary Electron ◽  
Nicotinamide Adenine ◽  
Nad Kinase ◽  
Pathogenic Potential

Nicotinamide adenine dinucleotide phosphate (NADPH) is the primary electron donor for reductive reactions that are essential for the biosynthesis of major cell components in all organisms. Nicotinamide adenine dinucleotide kinase (NADK) is the only enzyme that catalyzes synthesis of NADP(H) from NAD(H). While the enzymatic properties and physiological functions of NADK have been thoroughly studied, the role of NADK in bacterial pathogenesis remains unknown. Here, we used CRISPR interference to knockdown NADK gene expression in order to address the role of NADK in Staphylococcus aureus pathogenic potential. We find that NADK protects bacteria from antimicrobial defense mechanisms encountered in the host during infection such as oxidative and envelope stresses. Furthermore, we show that antioxidant properties of NADK promote S. aureus survival in infected macrophages. Remarkably, NADK inhibition drastically decreases mortality of zebrafish infected with S. aureus. These findings support a key role for NADK in bacteria interactions with innate immune cells and during infection. Last, we reveal that decreasing NADK expression increases S. aureus susceptibility to antibiotics, opening the way to development of synergistic treatments based on NADK inhibitors and current antibiotics.

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

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