High-resolution NMR Studies Research Articles

High Resolution NMR Studies of Nucleic Acids and Proteins

It has long been recognized that NMR can be used to investigate the solution structure and dynamics of biological polymers and to monitor many different parts of the molecule simultaneously. However, as recently as five years ago, even decapeptides presented a formidable challenge to the NMR spectroscopist. The major limitations have been three-fold: the great difficulty in assigning resonances to particular nuclei in the molecule, the lack of resolution in the spectrum due to the multitude of resonances from even a moderately small biopolymer, and the relatively low sensitivity of NMR. All of these limitations have been alleviated by the introduction of two-dimensional NMR (2DNMR) methods and the development of higher field strength spectrometers. 2DNMR spreads the spectral information into two frequency dimensions and allows simultaneous collection of infor­ mation about all resonances, thus improving the effective resolution and sensitivity. Methods for systematically obtaining reliable resonance assign­ ments using 2DNMR were first developed for proteins by Wuthrich and co­ workers, and later extended to other biopolymers. In the present review, we restrict ourselves to a discussion of the basic principles of the most important 2DNMR experiments and present some recent examples ; however, this article is not intended to be a comprehensive survey of all the recently published protein and nucleic acid NMR literature.

Observation of a plastic crystalline phase in solidMBBA

Wideline and high resolution NMR studies have been carried out in MBBA in its isotropic, nematic and solid phases. Isotropic and nematic spectra correspond to what has been reported earlier. In the solid phase, contrary to expectations, very intense narrow signals similar to signals of the isotropic phase have been observed for the first time at temperatures close to the solid \leftrightarrow nematic phase transition temperature. This indicates rapid reorientational or translational motion in the system. X-ray results, owever, confirm the existence of translational order. The results are interpreted as indicative of the existence of a plastic crystalline phase in MBBA.

ADP/ATP carrier protein from beef heart mitochondria has high amounts of tightly bound cardiolipin, as revealed by 31P nuclear magnetic resonance.

An unusual binding of cardiolipin to the ADP/ATP carrier has been found, which is distinguished by the relatively large amount and by the tightness of binding. High-resolution 31P NMR studies on the detergent-solubilized ADP/ATP carrier from beef heart mitochondria revealed narrow signals from phosphatidylcholine and phosphatidylethanolamine and a broadened signal of 30-40-Hz line width, suggestive of cardiolipin. Line broadening of this magnitude is to be expected when tumbling of the whole protein-detergent micelle is the only source of phosphorus spin-spin relaxation. Thus a strong immobilization of the protein-bound cardiolipin is inferred. By sucrose density gradient centrifugation phosphatidylcholine and phosphatidylethanolamine were removed, while approximately six +/- one molecules of cardiolipin remained tightly bound in the dimeric protein molecule. The cardiolipin binding was stable against treatment with sodium dodecyl sulfate although release of the inhibitor carboxyatractyloside revealed at least partial protein denaturation. Ca2+ ions did not readily interact either with the bound cardiolipin. Complete detachment of the bound phospholipid was achieved by a short heat pulse in the presence of sodium dodecyl sulfate. Denaturation of the carrier protein by guanidinium chloride or NaClO4 also led to release of the bound phospholipid. Thus different stages of protein denaturation must be envisaged.

A high-temperature high-resolution NMR study of 23Na, 27Al and 29Si in molten silicates

Molecular and atomic motions over longer distances, and with much lower frequencies than interatomic vibrations, have a major role in the energetic and dynamic properties of highly structured liquids such as molten aluminosilicates. Rearrangement with increasing temperature of the polymerized anionic network (composed of linked SiO44− and AlO45− tetrahedra) controls viscosity and influences thermal expansion and configurational heat capacity1,2. Diffusive motion of network modifying cations (such as Na+) through the structure allows electrical conductivity and probably also affects entropy. To study such motion directly and to compare liquid and glass structure, we have developed a novel high-temperature high-resolution NMR apparatus. We report here the first data on 23Na, 27Al, and 29Si in liquids in the system Na2O/Al2O3/SiO2 at temperatures to about 1,300 °C. Observed changes in NMR resonant frequencies (chemical shifts) give information on the effects of composition on local structure. Line shapes and widths, and relaxation time measurements, reveal details of the dynamics and of the transition from liquid to glass.

Supported organoactinides. High-resolution solid-state carbon-13 NMR studies of catalytically active, alumina-bound pentamethylcyclopentadienyl)thorium methyl and hydride complexes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSupported organoactinides. High-resolution solid-state carbon-13 NMR studies of catalytically active, alumina-bound pentamethylcyclopentadienyl)thorium methyl and hydride complexesPaul J. Toscano and Tobin J. MarksCite this: J. Am. Chem. Soc. 1985, 107, 3, 653–659Publication Date (Print):February 1, 1985Publication History Published online1 May 2002Published inissue 1 February 1985https://doi.org/10.1021/ja00289a017RIGHTS & PERMISSIONSArticle Views218Altmetric-Citations68LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (941 KB) Get e-Alerts Get e-Alerts

NMR and X-ray Investigations of a Plastic Crystalline Phase in MBBA

Wideline and high resolution NMR studies have been carried out on MBBA in its isotropic, nematic and solid phases. Isotropic and nematic phase spectra correspond to what has been reported earlier. In the solid phase, contrary to expectations, very intense narrow signals similar to signals of the isotropic phase have been observed for the first time at temperatures close to the solid \leftrightarrow nematic phase transition temperature. This indicates rapid reorientational or translational motion in the system. The X-ray results however confirm the existence of translational order. The results are interpreted as indicative of the existence of a plastic crystalline phase in MBBA.

Structure of cardioactive polypeptides from sea anemones. a high-resolution nmr study: By P. R. GOOLEY and R. S. NORTON. School of Biochemistry, University of New South Wales, Kensington, NSW 2033, Australia

Structure of cardioactive polypeptides from sea anemones. a high-resolution nmr study: By P. R. GOOLEY and R. S. NORTON. School of Biochemistry, University of New South Wales, Kensington, NSW 2033, Australia

High Resolution NMR Studies of Nucleic Acids and Proteins

Machine learning (ML) is transforming all areas of science. The complex and time-consuming calculations in molecular simulations are particularly suitable for an ML revolution and have already been profoundly affected by the application of existing ML ...Read More

High-resolution solid-state NMR study of the crystallization of hydroxysodalite

The crystallization of hydroxysodalite has been studied by means of high-resolution solid-state NMR of 29Si, 27Al and 23Na nuclei with the magic-angle sample-spinning technique. Information has been obtained on the crystallization process, and the mechanism is discussed.

Laser photo-CIDNP 1H NMR studies of lysozyme, ovalbumin, and their interactions

Laser photo-CIDNP NMR experiments allow for the selective observation of exposed aromatic residues in high-resolution 1H NMR studies of peptides and proteins. In studies designed to measure the change in exposure of these residues it is important to be able to differentiate between changes in CIDNP intensities resulting from conformational changes in the protein, protein association, or interactions with ligands, and other unwanted phenomena such as dye binding or competition for the dye. In an attempt to optimize, quantitate, and understand CIDNP enhancements for proteins two proteins, lysozyme and ovalbumin, have been studied, which are involved in ligand interactions, self association, and mutual interaction. The results obtained for these proteins under a variety of conditions have been compared with those for amino acids and mixtures of amino acids. Details of the optimization of the CIDNP experiment aimed at minimizing undesirable side reactions, and control experiments designed to distinguish real changes in amino acid side-chain exposure from other effects, are outlined.

High-resolution carbon-13 NMR study of silk fibroin in the solid state by the cross-polarization-magic angle spinning method. Conformational characterization of silk I and silk II type forms of Bombyx mori fibroin by the conformation-dependent carbon-13 chemical shifts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh-resolution carbon-13 NMR study of silk fibroin in the solid state by the cross-polarization-magic angle spinning method. Conformational characterization of silk I and silk II type forms of Bombyx mori fibroin by the conformation-dependent carbon-13 chemical shiftsHazime Saito, Ryoko Tabeta, Tetsuo Asakura, Yoshihiro Iwanaga, Akira Shoji, Takuo Ozaki, and Isao AndoCite this: Macromolecules 1984, 17, 7, 1405–1412Publication Date (Print):July 1, 1984Publication History Published online1 May 2002Published inissue 1 July 1984https://doi.org/10.1021/ma00137a018RIGHTS & PERMISSIONSArticle Views481Altmetric-Citations170LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (934 KB) Get e-Alerts Get e-Alerts

Gaussian pulses

An analysis is made of frequency-selective radiofrequency pulses used for high-resolution NMR studies of liquids. If the pulse envelope is rectangular, there are extensive sidelobes in the frequency-domain excitation pattern, whereas a Gaussian envelope gives a frequency-domain pattern (for the absolute-value mode) that is a slightly distorted Gaussian with no sidelobes. This affords much better selectivity. Furthermore the Gaussian pulse excites a signal with a phase angle which is almost a linear function of offset. The calculations are based on magnetization trajectories predicted by the Bloch equations, neglecting relaxation. It is shown that at appreciable offsets from resonance the Gaussian pulse produces a characteristic “teardrop” trajectory which always terminates near the +Z axis, irrespective of offset ΔB. Examples of applications of Gaussian-shaped pulses include the investigation of the fine structure on carbon-13 resonances, selective coherence transfer experiments between protons, and nuclear Overhauser effect measurements in crowded proton spectra.

A solid-state high-resolution carbon-13 NMR study of octaethylporphyrin and its zinc(II) and nickel(II) metal complexes using CP-MAS techniques

Interpretation des spectres observes par l'empechement de la tautomerie parmi les cycles pyrroles et l'effet d'ecran chimique du au courant de cycle. Discussion

Carbon-13 NMR studies of native and modified ovine submaxillary mucin.

Natural abundance 13C NMR spectroscopy has been used to study the solution structure and dynamics of the ovine submaxillary mucin (OSM). Results at both 45.3 and 67.9 MHz show the extremely viscous mucin to possess sufficient internal segmental flexibility to allow high-resolution 13C NMR studies. Essentially all of the resonances in the spectra have been assigned to individual carbons of the carbohydrate disaccharide side chain alpha- NeuNAc2 ----6 alpha-Gal-NAc-Ser/Thr and to the protonated carbons of the major peptide residues. Spin-lattice relaxation times and nuclear Overhauser enhancements reveal that the internal mobility of the mucin is unaffected by large changes in molecular weight and hence bulk viscosity. On the basis of the relaxation measurements the peptide and carbohydrate side chain mobilities increase stepwise from the glycosylated peptide residue alpha-carbons to the terminal sialic acid (NeuNAc) side-chain C9 carbon. Removal of the terminal sialic acid C8 and C9 side-chain carbons as well as the complete removal of the NeuNAc residue does not alter the dynamics of the peptide core. However, the removal of carbons C8 and C9 from the NeuNAc residue produces an increase in its ring mobility or conformational flexibility. Complete removal of sialic acid produces an increase in the mobility or flexibility of the GalNAc ring and reduces the chemical shift sensitivity of the GalNAc ring carbons to the different serine and threonine linkages. The pKa value for the sialic acid carboxyl group in the intact mucin is 2.0, while it increases to 2.4 after the removal of the NeuNAc C8 and C9 side-chain carbons. This change in pKa confirms the intramolecular hydrogen bond interaction of the C8 hydroxyl with the C2 carboxyl group in the alpha-NeuNAc residue as previously suggested by Jennings and Bhattacharjee [ Jennings , H.J., & Bhattacharjee , A.K. (1977) Carbohydr . Res. 55, 105-112]. The relaxation time values and temperature dependence of the chemical shift of the NeuNAc C7 carbon suggest that this group is also involved in an intramolecular interaction. Overall the 13C NMR results indicate that the relatively simple mucous glycoprotein, OSM, is a highly extended and internally flexible molecule which in solution possesses little secondary structure.

13C high-resolution NMR study of doped polyacetylene

13C high resolution NMR spectra of doped trans polyacetylene, (CH) x , have been measured. A spectrum of (CH) x doped with AsF 5 shows a downfield shift, while that with potassium an upfield shift. The charge distribution and the existence of sp 3 hybridized carbon on halogen-doped (CH) x chains are discussed.

13C high-resolution NMR study of undoped polyacetylene

13C NMR spectra of undoped polyacetylene,(CH) x, have been measured. The existence of 3.4 mol% methylene moieties as defects in the (CH) x chains has been observed in trans-(CH) x. Measurements of partially cis-to-trans isomerized (CH) x suggest the existence of isolated cis regions.

High-resolution proton NMR studies of gangliosides. 2. Use of two-dimensional nuclear Overhauser effect spectroscopy and sialylation shifts for determination of oligosaccharide sequence and linkage sites.

Homonuclear two-dimensional proton nuclear Overhauser effect (2-D-NOE) spectra have been obtained for asialo-GM2 (4) and gangliosides GM2 (8) and GM1 (9) at 500 MHz and 40 degrees C in Me2SO-d6-D2O (98:2 v/v). The anomeric protons of each oligosaccharide residue of 4, 8, and 9 are observed to NOE couple via intraresidue 1,3- and 1,5-diaxial interactions and interresidue interactions across the glycosidic linkages. The former couplings are used to confirm the H-3 and H-5 assignments for each residue. From the latter couplings the sequence and glycosidic linkage sites of all oligosaccharide residues, except the sialic acid residues, are revealed. Sialic acid attachment sites are determined for the monosialogangliosides (6-9) through consideration of sialylation-induced glycosidation shifts. Combination of the above sequence and linkage-site data with the monosaccharide composition, anomeric configurations, and characterization of the aglycon (information obtained via two-dimensional spin-echo J-correlated spectroscopy or 2-D-SECSY) allows complete assignment of monosialoganglioside primary structure, independent of other methods of structural analysis. Compared to conventional chemical and enzymatic methods, high-resolution two-dimensional proton nuclear magnetic resonance spectroscopy has the advantages of speed, sensitivity, and sample preservation.

High-resolution proton NMR studies of gangliosides. 1. Use of homonuclear two-dimensional spin-echo J-correlated spectroscopy for determination of residue composition and anomeric configurations.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh-resolution proton NMR studies of gangliosides. 1. Use of homonuclear two-dimensional spin-echo J-correlated spectroscopy for determination of residue composition and anomeric configurationsTheodore A. W. Koerner, Jr., James H. Prestegard, Peter C. Demou, and Robert K. YuCite this: Biochemistry 1983, 22, 11, 2676–2687Publication Date (Print):May 1, 1983Publication History Published online1 May 2002Published inissue 1 May 1983https://doi.org/10.1021/bi00280a014RIGHTS & PERMISSIONSArticle Views263Altmetric-Citations189LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-Alerts Get e-Alerts

A highly siliceous structural analog of zeolite Y: high-resolution solid-state silicon-29 and aluminum-27 NMR studies

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA highly siliceous structural analog of zeolite Y: high-resolution solid-state silicon-29 and aluminum-27 NMR studiesJ. Klinowski, J. M. Thomas, C. A. Fyfe, G. C. Gobbi, and J. S. HartmanCite this: Inorg. Chem. 1983, 22, 1, 63–66Publication Date (Print):January 1, 1983Publication History Published online1 May 2002Published inissue 1 January 1983https://doi.org/10.1021/ic00143a016RIGHTS & PERMISSIONSArticle Views345Altmetric-Citations69LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (559 KB) Get e-Alerts Get e-Alerts

High-resolution proton nuclear magnetic resonance studies of the nickel(II) derivative of azurin.

High-resolution (360 and 470 MHz) 1H NMR studies of Ni(II) azurin, the nickel(II) derivative of the blue copper protein azurin, are reported. The aliphatic resonances of Ni(II) azurin closely parallel those of apoazurin and Cu(I) azurin and indicate that no major structural changes are associated with the binding of nickel(II). The magnetic moment of Ni(II) azurin (mueff = 3.2 muB) is in keeping with a pseudotetrahedral coordination environment like that of Cu(I) azurin. Resonances of protons from the ligand moieties are shifted as far as 125 ppm downfield from 4,4-dimethyl-4-silapentane-1-sulfonate and as far as 20 ppm upfield by internal fields due to the nickel center. One of these strongly shifted resonances is assigned to the methyl protons of the methionine ligand. From spectra of Ni(II) azurin as a function of pH, the pKa' values of histidine-35 and histidine-83 have been measured to be approximately 6.0 and 7.5, respectively. Histidine-35 titrates in a discontinuous fashion, and, significantly, so do several of the isotropically shifted ligand protons, also within experimental error with the same pHmid. This result reinforces the suggestion that the conformational change coupled to the protonation of histidine-35 plays an important role in regulating electron transfer reactions of native azurin [Silvestrini, M. C., Brunori, M., Wilson, M. T., & Darley-Usmar, V. M. (1981) J. Inorg. Biochem. 14, 327-338].