scholarly journals Use of1H Nuclear Magnetic Resonance To Measure Intracellular Metabolite Levels during Growth and Asexual Sporulation in Neurospora crassa

2011 ◽  
Vol 10 (6) ◽  
pp. 820-831 ◽  
Author(s):  
James D. Kim ◽  
Kayla Kaiser ◽  
Cynthia K. Larive ◽  
Katherine A. Borkovich
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Neurospora Crassa ◽  
Nutrient Sensing ◽  
Wild Type ◽  
Content Type ◽  
Asexual Sporulation ◽  
Significant Difference ◽  
High Sucrose ◽  
Nuclear Magnetic

ABSTRACTConidiation is an asexual sporulation pathway that is a response to adverse conditions and is the main mode of dispersal utilized by filamentous fungal pathogens for reestablishment in a more favorable environment. Heterotrimeric G proteins (consisting of α, β, and γ subunits) have been shown to regulate conidiation in diverse fungi. Previous work has demonstrated that all three of the Gα subunits in the filamentous fungusNeurospora crassaaffect the accumulation of mass on poor carbon sources and that loss ofgna-3leads to the most dramatic effects on conidiation. In this study, we used1H nuclear magnetic resonance (NMR) to profile the metabolome ofN. crassain extracts isolated from vegetative hyphae and conidia from cultures grown under conditions of high or low sucrose. We compared wild-type and Δgna-3strains to determine whether lack ofgna-3causes a significant difference in the global metabolite profile. The results demonstrate that the global metabolome of wild-type hyphae is influenced by carbon availability. The metabolome of the Δgna-3strain cultured on both high and low sucrose is similar to that of the wild type grown on high sucrose, suggesting an overall defect in nutrient sensing in the mutant. However, analysis of individual metabolites revealed differences in wild-type and Δgna-3strains cultured under conditions of low and high sucrose.

scholarly journals Pyrrolamide DNA Gyrase Inhibitors: Fragment-Based Nuclear Magnetic Resonance Screening To Identify Antibacterial Agents

2011 ◽  
Vol 56 (3) ◽  
pp. 1240-1246 ◽  
Author(s):  
Ann E. Eakin ◽  
Oluyinka Green ◽  
Neil Hales ◽  
Grant K. Walkup ◽  
Shanta Bist ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Antibacterial Agents ◽  
Dna Gyrase ◽  
Mouse Lung ◽  
Infection Model ◽  
Lead Compound ◽  
Content Type ◽  
Gyrase Inhibitors ◽  
Nuclear Magnetic

ABSTRACTDNA gyrase is an essential enzyme in bacteria, and its inhibition results in the disruption of DNA synthesis and, subsequently, cell death. The pyrrolamides are a novel class of antibacterial agents targeting DNA gyrase. These compounds were identified by a fragment-based lead generation (FBLG) approach using nuclear magnetic resonance (NMR) screening to identify low-molecular-weight compounds that bind to the ATP pocket of DNA gyrase. A pyrrole hit with a binding constant of 1 mM formed the basis of the design and synthesis of a focused library of compounds that resulted in the rapid identification of a lead compound that inhibited DNA gyrase with a 50% inhibitory concentration (IC50) of 3 μM. The potency of the lead compound was further optimized by utilizing iterative X-ray crystallography to yield DNA gyrase inhibitors that also displayed antibacterial activity. Spontaneous mutants were isolated inStaphylococcus aureusby plating on agar plates containing pyrrolamide 4 at the MIC. The resistant variants displayed 4- to 8-fold-increased MIC values relative to the parent strain. DNA sequencing revealed two independent point mutations in the pyrrolamide binding region of thegyrBgenes from these variants, supporting the hypothesis that the mode of action of these compounds was inhibition of DNA gyrase. Efficacy of a representative pyrrolamide was demonstrated againstStreptococcus pneumoniaein a mouse lung infection model. These data demonstrate that the pyrrolamides are a novel class of DNA gyrase inhibitors with the potential to deliver future antibacterial agents targeting multiple clinical indications.

scholarly journals Catabolism of Glucose and Lactose in Bifidobacterium animalis subsp. lactis, Studied by13C Nuclear Magnetic Resonance

2013 ◽  
Vol 79 (24) ◽  
pp. 7628-7638 ◽  
Author(s):  
Irene González-Rodríguez ◽  
Paula Gaspar ◽  
Borja Sánchez ◽  
Miguel Gueimonde ◽  
Abelardo Margolles ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Metabolic Pathways ◽  
Transcriptional Analysis ◽  
Content Type ◽  
Bifidobacterium Animalis ◽  
Metabolic Flux Distribution ◽  
Nuclear Magnetic ◽  
In Cells

ABSTRACTBifidobacteria are widely used as probiotics in several commercial products; however, to date there is little knowledge about their carbohydrate metabolic pathways. In this work, we studied the metabolism of glucose and lactose in the widely used probiotic strainBifidobacterium animalissubsp.lactisBB-12 byin vivo13C nuclear magnetic resonance (NMR) spectroscopy. The metabolism of [1-13C]glucose was characterized in cells grown in glucose as the sole carbon source. Moreover, the metabolism of lactose specifically labeled with13C on carbon 1 of the glucose or the galactose moiety was determined in suspensions of cells grown in lactose. These experiments allowed the quantification of some intermediate and end products of the metabolic pathways, as well as determination of the consumption rate of carbon sources. Additionally, the labeling patterns in metabolites derived from the metabolism of glucose specifically labeled with13C on carbon 1, 2, or 3 in cells grown in glucose or lactose specifically labeled in carbon 1 of the glucose moiety ([1-13Cglucose]lactose), lactose specifically labeled in carbon 1 of the galactose moiety ([1-13Cgalactose]lactose), and [1-13C]glucose in lactose-grown cells were determined in cell extracts by13C NMR. The NMR analysis showed that the recovery of carbon was fully compatible with the fructose 6-phosphate, or bifid, shunt. The activity of lactate dehydrogenase, acetate kinase, fructose 6-phosphate phosphoketolase, and pyruvate formate lyase differed significantly between glucose and lactose cultures. The transcriptional analysis of several putative glucose and lactose transporters showed a significant induction of Balat_0475 in the presence of lactose, suggesting a role for this protein as a lactose permease. This report provides the firstin vivoexperimental evidence of the metabolic flux distribution in the catabolic pathway of glucose and lactose in bifidobacteria and shows that the bifid shunt is the only pathway involved in energy recruitment from these two sugars. On the basis of our experimental results, a model of sugar metabolism inB. animalissubsp.lactisis proposed.

scholarly journals Nuclear Magnetic Resonance Study of Cerebrospinal Fluid From Patients With Multiple Sclerosis

1993 ◽  
Vol 20 (3) ◽  
pp. 194-198 ◽  
Author(s):  
Lynch Joanna ◽  
Peeling James ◽  
Auty Anthony ◽  
R. Sutherland Garnette
Keyword(s):  
Multiple Sclerosis ◽  
Nuclear Magnetic Resonance ◽  
Cerebrospinal Fluid ◽  
Magnetic Resonance ◽  
Progressive Multiple Sclerosis ◽  
Aids Dementia Complex ◽  
Proton Nuclear Magnetic Resonance ◽  
Significant Difference ◽  
Metabolite Concentrations ◽  
Nuclear Magnetic

ABSTRACT:Proton nuclear magnetic resonance (NMR) spectroscopy was used to examine cerebrospinal fluid (CSF) from patients (n = 30) with actively progressive multiple sclerosis (MS). Metabolite concentrations obtained from the spectra were compared to those determined from the spectra of CSF from control patients (n = 27) with benign spinal disorders. No significant difference was found between the 2 groups for most constituents, including lactate, glutamine, citrate, creatine and creatinine, and glucose. Acetate levels were significantly higher in MS patients, while formate levels were significantly lower, than the controls. There were no significant differences in metabolite concentrations in CSF from early and longstanding MS patients. A peak due to an unidentified compound was found at 2.82 ppm in the spectra of CSF from patients with actively progressive MS, but not in the spectra of CSF from the controls. The peak was not found in spectra of CSF from patients with AIDS dementia complex (n = 9) or Parkinson's disease (n = 5), but it did appear in spectra of CSF from 1 patient with Jakob-Creutzfeldt disease (out of 3 examined) and from 1 patient (out of 7) with Guillan-Barré disease. The unidentified compound is volatile and, from the chemical shift of the observed NMR peak, is probably an N-methyl compound. As such, it may be an intermediate in the cholino-glycine cycle, in which an abnormality has been proposed to exist in MS patients.

scholarly journals Analysis of the Aspergillus fumigatus Biofilm Extracellular Matrix by Solid-State Nuclear Magnetic Resonance Spectroscopy

2015 ◽  
Vol 14 (11) ◽  
pp. 1064-1072 ◽  
Author(s):  
Courtney Reichhardt ◽  
Jose A. G. Ferreira ◽  
Lydia-Marie Joubert ◽  
Karl V. Clemons ◽  
David A. Stevens ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Extracellular Matrix ◽  
Solid State ◽  
Magnetic Resonance ◽  
Aspergillus Fumigatus ◽  
Fungal Infections ◽  
Resonance Spectroscopy ◽  
Chronic Infections ◽  
Content Type ◽  
Nuclear Magnetic

ABSTRACTAspergillus fumigatusis commonly responsible for lethal fungal infections among immunosuppressed individuals.A. fumigatusforms biofilm communities that are of increasing biomedical interest due to the association of biofilms with chronic infections and their increased resistance to antifungal agents and host immune factors. Understanding the composition of microbial biofilms and the extracellular matrix is important to understanding function and, ultimately, to developing strategies to inhibit biofilm formation. We implemented a solid-state nuclear magnetic resonance (NMR) approach to define compositional parameters of theA. fumigatusextracellular matrix (ECM) when biofilms are formed in RPMI 1640 nutrient medium. Whole biofilm and isolated matrix networks were also characterized by electron microscopy, and matrix proteins were identified through protein gel analysis. The13C NMR results defined and quantified the carbon contributions in the insoluble ECM, including carbonyls, aromatic carbons, polysaccharide carbons (anomeric and nonanomerics), aliphatics, etc. Additional15N and31P NMR spectra permitted more specific annotation of the carbon pools according to C-N and C-P couplings. Together these data show that theA. fumigatusECM produced under these growth conditions contains approximately 40% protein, 43% polysaccharide, 3% aromatic-containing components, and up to 14% lipid. These fundamental chemical parameters are needed to consider the relationships between composition and function in theA. fumigatusECM and will enable future comparisons with other organisms and withA. fumigatusgrown under alternate conditions.

Novel self-coloured polymers based on new fluorescent naphthalimide derivatives: synthesis, characterisation and photophysical properties

2017 ◽  
Vol 46 (3) ◽  
pp. 244-250 ◽  
Author(s):  
Hanieh Shaki ◽  
Alireza Khosravi ◽  
Kamaladin Gharanjig
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Polymer Chain ◽  
Fluorescent Dyes ◽  
Proton Nuclear Magnetic Resonance ◽  
Quantum Yields ◽  
The Novel ◽  
Acrylic Polymer ◽  
Content Type ◽  
Nuclear Magnetic

Purpose In this study, two novel fluorescent dyes, based on naphthalimide derivatives have been synthesised from acenaphthene as a starting material. The ability of the dyes to graft to polymer chain was then demonstrated. The novel synthesised dyes and self-coloured polymers were characterised by a variety of techniques. Design/methodology/approach The novel dyes were prepared through by halogenation, oxidation, imidation and amination reactions. All steps of these processes were monitored by thin layer chromatography. The fluorescent dyes and their intermediates were characterised by differential scanning calorimeter, fourier transform infrared spectroscopy (FTIR), Proton Nuclear Magnetic Resonance (1H-NMR) and carbon-13 nuclear magnetic resonance (13-CNMR) spectroscopic techniques. The molar extinction coefficients and absorption maximum wavelength were obtained by examining the dyes and polymer solutions in Dimethylformamide (DMF) and toluene solvents. The fluorescency of novel dyes and self-coloured polymers was evaluated. Their quantum yields and Stokes shift values were determined as DMF and toluene solutions. The percentage of the covalently bounded dyes into the polymer chain was calculated. Findings The characterisation of the synthesised dyes and self-coloured polymers verified their structural correctness. The results of reaction dyes with resin demonstrated that the dyes were covalently bonded to the chain of an acrylic polymer (resin) containing carboxylic acid groups giving self-coloured polymers. The extent of fluorescence of the synthesised dyes and their polymers showed that compounds containing functional amino group in C-4 position of naphthalimide ring have high fluorescence properties. Originality/value This study is original. Self-coloured polymers based on acrylic were synthesised by novel naphthalimide dyes with acrylic resin for the first time, successfully. The novel dyes and their self-coloured polymers exhibit good and acceptable fluorescent activity.

Water Dynamics of Mung bean (Vigna radiata) Sprouts Treated with 6-Benzylaminopurine: Discrimination by Low-Field Nuclear Magnetic Resonance and Spectrometry

2018 ◽  
Vol 14 (4) ◽  
Author(s):  
Zhuyi Lin ◽  
Ruiying Wang ◽  
Siqi Wang ◽  
Mingqian Tan
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Mung Bean ◽  
Control Sample ◽  
Water Dynamics ◽  
Low Field ◽  
Significant Difference ◽  
Bean Sprouts ◽  
Lf Nmr ◽  
Nuclear Magnetic

AbstractMung bean sprouts are a kind of favorite healthy food across the world. As a forbidden plant hormone cytokinins, the use of 6-benzylaminopurine (6-BAP) in promoting the growth of bean sprouts is forbidden due to its safety concerns. Rapid analysis of 6-BAP treated bean sprouts is required to assess their growth changes and discriminate them from the normal sample. In this study, the water dynamics of growth for 6-BAP treated bean sprouts was monitored by the low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging. A simplified cartoon model of the water dynamics was proposed to explain the LF-NMR analysis result. Principal component analysis of the NMR relaxation data clearly showed the different water distribution of 6-BAP treated bean sprouts from the control sample. The juice of 6-BAP treated bean sprouts showed significant difference in the ultraviolet absorption and fluorescence spectra. Therefore, combining the spectrometry, the LF-NMR may have potential for rapid discrimination of the 6-BAP treated bean sprouts.

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