Related ArticlesEC-SPE-stripline-NMR analysis of reactive products: a feasibility study.
Anal Bioanal Chem. 2013 Jun 30;
Authors: Falck D, Oosthoek-de Vries AJ, Kolkman A, Lingeman H, Honing M, Wijmenga SS, Kentgens AP, Niessen WM
Abstract
Flow-through electrochemical conversion (EC) of drug-like molecules was hyphenated to miniaturized nuclear magnetic resonance spectroscopy (NMR) via on-line solid-phase extraction (SPE). After EC of the prominent p38? mitogen-activated protein kinase inhibitor BIRB796 into its reactive products, the SPE step provided preconcentration of the EC products and solvent exchange for NMR analysis. The acquisition of NMR spectra of the mass-limited samples was achieved in a stripline probe with a detection volume of 150*nL offering superior mass sensitivity. This hyphenated EC-SPE-stripline-NMR setup enabled the detection of the reactive products using only minute amounts of substrate. Furthermore, the integration of conversion and detection into one flow setup counteracts incorrect assessments caused by the degradation of reactive products. However, apparent interferences of the NMR magnetic field with the EC, leading to a low product yield, so far demanded relatively long signal averaging. A critical assessment of what is and what is not (yet) possible with this approach is presented, for example in terms of structure elucidation and the estimation of concentrations. Additionally, promising routes for further improvement of EC-SPE-stripline-NMR are discussed.
PMID: 23812883 [PubMed - as supplied by publisher]
Protein lysine-N? alkylation and O-phosphorylation mediated by DTT-generated reactive oxygen species
Protein lysine-N? alkylation and O-phosphorylation mediated by DTT-generated reactive oxygen species
Abstract
Reactive oxygen species (ROS) play crucial roles in physiology and pathology. In this report, we use NMR spectroscopy and mass spectrometry (MS) to demonstrate that proteins (galectin-1, ubiquitin, RNase, cytochrome c, myoglobin, and lysozyme) under reducing conditions with dithiothreitol (DTT) become alkylated at lysine-N? groups and O-phosphorylated at serine and threonine residues. These adduction reactions only occur in the presence of monophosphate, potassium, trace metals...
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02-03-2013 09:54 AM
Journal Highlight: Quantitative NMR: An applicable method for quantitative analysis of medicinal plant extracts and herbal products
Journal Highlight: Quantitative NMR: An applicable method for quantitative analysis of medicinal plant extracts and herbal products
http://www.spectroscopynow.com/common/images/thumbnails/13abcca009b.jpgA quantitative NMR method has been reported for quantitative analysis of three medicinal plant extracts and their herbal products without the need of authentic standards.
Source: Spectroscopynow.com
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02-03-2013 08:49 AM
The feasibility of parameterizing four-state equilibria using relaxation dispersion measurements
The feasibility of parameterizing four-state equilibria using relaxation dispersion measurements
Abstract Coupled equilibria play important roles in controlling information flow in biochemical systems, including allosteric molecules and multidomain proteins. In the simplest case, two equilibria are coupled to produce four interconverting states. In this study, we assessed the feasibility of determining the degree of coupling between two equilibria in a four-state system via relaxation dispersion measurements. A major bottleneck in this effort is the lack of efficient approaches to...
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09-30-2011 08:01 PM
Metabolic relationship between polyhydroxyalkanoic acid and rhamnolipid synthesis in Pseudomonas aeruginosa: comparative 像C NMR analysis of the products in wild-type and mutants.
Metabolic relationship between polyhydroxyalkanoic acid and rhamnolipid synthesis in Pseudomonas aeruginosa: comparative 像C NMR analysis of the products in wild-type and mutants.
Metabolic relationship between polyhydroxyalkanoic acid and rhamnolipid synthesis in Pseudomonas aeruginosa: comparative 像C NMR analysis of the products in wild-type and mutants.
J Biotechnol. 2011 Jan 10;151(1):30-42
Authors: Choi MH, Xu J, Gutierrez M, Yoo T, Cho YH, Yoon SC
Polyhydroxyalkanoic acids (PHAs) and rhamnolipids considered as biotechnologically important...
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04-28-2011 03:12 PM
[NMR paper] ALARM NMR: a rapid and robust experimental method to detect reactive false positives
ALARM NMR: a rapid and robust experimental method to detect reactive false positives in biochemical screens.
Related Articles ALARM NMR: a rapid and robust experimental method to detect reactive false positives in biochemical screens.
J Am Chem Soc. 2005 Jan 12;127(1):217-24
Authors: Huth JR, Mendoza R, Olejniczak ET, Johnson RW, Cothron DA, Liu Y, Lerner CG, Chen J, Hajduk PJ
High-throughput screening (HTS) of large compound collections typically results in numerous small molecule hits that must be carefully evaluated to identify valid drug...
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11-24-2010 11:14 PM
[NMR paper] Internal mobility of reactive-site-hydrolyzed recombinant Cucurbita maxima trypsin in
Internal mobility of reactive-site-hydrolyzed recombinant Cucurbita maxima trypsin inhibitor-V characterized by NMR spectroscopy: evidence for differential stabilization of newly formed C- and N-termini.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--pubs.acs.org-images-acspubs.jpg Related Articles Internal mobility of reactive-site-hydrolyzed recombinant Cucurbita maxima trypsin inhibitor-V characterized by NMR spectroscopy: evidence for differential stabilization of newly formed C- and N-termini.
Biochemistry. 1996 Sep 24;35(38):12503-10
...
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08-22-2010 02:20 PM
[NMR paper] The use of 19F NMR in the study of protein alkylation by fluorinated reactive interme
The use of 19F NMR in the study of protein alkylation by fluorinated reactive intermediates.
Related Articles The use of 19F NMR in the study of protein alkylation by fluorinated reactive intermediates.
Adv Exp Med Biol. 1991;283:735-8
Authors: Harris JW, Anders MW
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08-21-2010 11:16 PM
[NMR software blog] Natural Products
Natural Products
http://1.bp.blogspot.com/_ROkYShLRKqA/SteNWieFqCI/AAAAAAAAARk/qKuAY5zIiGo/s400/antiphase.png
A reader asked me: "What is the shape of a 2-D peak?" and my answer was: "Exponential! (in time domain)". This is all you need to know, I think. The picture should help, as always. If you are reading this blog, it means that you have something like a computer. Even the iPhone is a computer (you can run programs on it) and can display my blog. I suspect, however, that you have a better computer, like I do.
You can use your computer to run simulations and more: you can ask it to...
EC-SPE-stripline-NMR analysis of reactive products: a feasibility study.
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