Related ArticlesTwo-dimensional NMR spectroscopy reveals cation-triggered backbone degradation in polysulfone-based anion exchange membranes.
Proc Natl Acad Sci U S A. 2013 Feb 12;110(7):2490-5
Authors: Arges CG, Ramani V
Abstract
Anion exchange membranes (AEMs) find widespread applications as an electrolyte and/or electrode binder in fuel cells, electrodialysis stacks, flow and metal-air batteries, and electrolyzers. AEMs exhibit poor stability in alkaline media; their degradation is induced by the hydroxide ion, a potent nucleophile. We have used 2D NMR techniques to investigate polymer backbone stability (as opposed to cation stability) of the AEM in alkaline media. We report the mechanism behind a peculiar, often-observed phenomenon, wherein a demonstrably stable polysulfone backbone degrades rapidly in alkaline solutions upon derivatization with alkaline stable fixed cation groups. Using COSY and heteronuclear multiple quantum correlation spectroscopy (2D NMR), we unequivocally demonstrate that the added cation group triggers degradation of the polymer backbone in alkaline via quaternary carbon hydrolysis and ether hydrolysis, leading to rapid failure. This finding challenges the existing perception that having a stable cation moiety is sufficient to yield a stable AEM and emphasizes the importance of the often ignored issue of backbone stability.
[NMR paper] pH-triggered, activated-state conformations of the influenza hemagglutinin fusion peptide revealed by NMR.
pH-triggered, activated-state conformations of the influenza hemagglutinin fusion peptide revealed by NMR.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--highwire.stanford.edu-icons-externalservices-pubmed-custom-pnas_full_free.gif http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--highwire.stanford.edu-icons-externalservices-pubmed-custom-pnas_full.gif http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.pubmedcentral.nih.gov-corehtml-pmc-pmcgifs-pubmed-pmc.gif Related Articles pH-triggered, activated-state conformations of the influenza hemagglutinin fusion...
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[NMR paper] Detection of closed influenza virus hemagglutinin fusion peptide structures in membranes by backbone (13)CO- (15)N rotational-echo double-resonance solid-state NMR.
Detection of closed influenza virus hemagglutinin fusion peptide structures in membranes by backbone (13)CO- (15)N rotational-echo double-resonance solid-state NMR.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--production.springer.de-OnlineResources-Logos-springerlink.gif Related Articles Detection of closed influenza virus hemagglutinin fusion peptide structures in membranes by backbone (13)CO- (15)N rotational-echo double-resonance solid-state NMR.
J Biomol NMR. 2013 Jan 18;
Authors: Ghosh U, Xie L, Weliky DP
Abstract...
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Longitudinal exchange: an alternative strategy towards quantification of dynamics parameters in ZZ exchange spectroscopy
Longitudinal exchange: an alternative strategy towards quantification of dynamics parameters in ZZ exchange spectroscopy
Abstract Longitudinal exchange experiments facilitate the quantification of the rates of interconversion between the exchanging species, along with their longitudinal relaxation rates, by analyzing the time-dependence of direct correlation and exchange cross peaks. Here we present a simple and robust alternative to this strategy, which is based on the combination of two complementary experiments, one with and one without resolving exchange cross peaks. We show that...
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09-30-2011 08:01 PM
An iminodiacetic acid based lanthanide binding tag for paramagnetic exchange NMR spectroscopy.
An iminodiacetic acid based lanthanide binding tag for paramagnetic exchange NMR spectroscopy.
An iminodiacetic acid based lanthanide binding tag for paramagnetic exchange NMR spectroscopy.
Angew Chem Int Ed Engl. 2011 May 2;50(19):4403-6
Authors: Swarbrick JD, Ung P, Chhabra S, Graham B
PMID: 21480444
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08-19-2011 02:56 PM
Site-Specific Solid-State NMR Detection of Hydrogen-Deuterium Exchange Reveals Conformational Changes in a 7-Helical Transmembrane Protein.
Site-Specific Solid-State NMR Detection of Hydrogen-Deuterium Exchange Reveals Conformational Changes in a 7-Helical Transmembrane Protein.
Site-Specific Solid-State NMR Detection of Hydrogen-Deuterium Exchange Reveals Conformational Changes in a 7-Helical Transmembrane Protein.
Biophys J. 2011 Aug 3;101(3):L23-L25
Authors: Wang S, Shi L, Kawamura I, Brown LS, Ladizhansky V
Solid-state NMR spectroscopy is an efficient tool for following conformational dynamics of membrane proteins at atomic resolution. We used this technique for the site-specific...
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08-03-2011 12:00 PM
NMR-based metabonomic investigation of heat stress in myotubes reveals a time-depende
NMR-based metabonomic investigation of heat stress in myotubes reveals a time-dependent change in the metabolites.
Related Articles NMR-based metabonomic investigation of heat stress in myotubes reveals a time-dependent change in the metabolites.
J Agric Food Chem. 2010 May 26;58(10):6376-86
Authors: Straadt IK, Young JF, Bross P, Gregersen N, Oksbjerg N, Theil PK, Bertram HC
NMR-based metabonomics was applied to elucidate the time-dependent stress responses in mouse myotubes after heat exposure of either 42 or 45 degrees C for 1 h. Principal...
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10-19-2010 04:51 PM
Two-dimensional heteronuclear saturation transfer difference NMR reveals detailed int
Two-dimensional heteronuclear saturation transfer difference NMR reveals detailed integrin αvβ6 protein-peptide interactions.
Related Articles Two-dimensional heteronuclear saturation transfer difference NMR reveals detailed integrin αvβ6 protein-peptide interactions.
Chem Commun (Camb). 2010 Sep 13;
Authors: Wagstaff JL, Vallath S, Marshall JF, Williamson RA, Howard MJ
We report the first example of peptide-protein heteronuclear two-dimensional (2D) saturation transfer difference nuclear magnetic resonance (STD NMR). This method, resulting in...
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09-15-2010 02:26 PM
[NMR paper] Source of transport site asymmetry in the band 3 anion exchange protein determined by
Source of transport site asymmetry in the band 3 anion exchange protein determined by NMR measurements of external Cl- affinity.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--pubs.acs.org-images-acspubs.jpg Related Articles Source of transport site asymmetry in the band 3 anion exchange protein determined by NMR measurements of external Cl- affinity.
Biochemistry. 1996 Dec 3;35(48):15228-35
Authors: Liu D, Kennedy SD, Knauf PA
Flux measurements indicate that a far greater number of unloaded band 3 anion transport sites face the...
Two-dimensional NMR spectroscopy reveals cation-triggered backbone degradation in polysulfone-based anion exchange membranes.
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