1
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Study on the influence of oxidative stress on the fibrillization of fibrinogen. Biochem J 2016; 473:4373-4384. [DOI: 10.1042/bcj20160702] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/27/2016] [Accepted: 10/04/2016] [Indexed: 12/25/2022]
Abstract
Human fibrinogen is an important coagulation factor as well as an independent predictor of coronary heart disease and stroke. Analysis of dysfibrinogens may provide useful information and help us to understand the molecular defects in fibrin polymerization. In the present study, we investigated the influence of oxidative stress of fibrinogen induced by H2O2 on the polymerization state of fibrin. UV absorbance spectroscopy, circular dichroism, ζ-potential, dynamic light scattering and steady shear viscosity were all employed to study the influence of oxidative stress on the molecular structure, the surface charges, and the size and shape of fibrinogen molecules. The fibrin morphology obtained was imaged and investigated using atomic force microscopy. The results demonstrated that the cross-linking, branching and height distribution of formed fibrin will be influenced by the oxidative stress of fibrinogen. This study presents new insights into the aggregation behaviour of fibrinogen and will be helpful to understand the formation mechanism of thrombosis under oxidative stress.
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2
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Huang J, Meuwly M. Explicit Hydrogen-Bond Potentials and Their Application to NMR Scalar Couplings in Proteins. J Chem Theory Comput 2015; 6:467-76. [PMID: 26617302 DOI: 10.1021/ct9005695] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrogen bonds (H bonds) are fundamental for the stability, structure, and dynamics of chemically and biologically relevant systems. One of the direct means to detect H bonds in proteins is NMR spectroscopy. As H bonds are dynamic in nature, atomistic simulations offer a meaningful way to characterize and analyze properties of hydrogen bonds, provided a sufficiently accurate interaction potential is available. Here, we use explicit H-bond potentials to investigate scalar coupling constants (h3)JNC' and characterize the conformational ensemble for increasingly accurate intermolecular potentials. By considering a range of proteins with different overall topology a general procedure to improve the hydrogen-bonding potential ("morphing potentials") based on experimental information is derived. The robustness of this approach is established through explicit simulations in full solvation and comparison with experimental results. The H-bond potentials used here lead to more directional H bonds than conventional electrostatic representations employed in molecular mechanics potentials. It is found that the optimized potentials lead to H-bond geometries in remarkable agreement with previous ab initio and knowledge-based approaches to H bonds in model systems and in proteins. This suggests that, by combining theory, computation, and experimental data, H-bonding potentials can be improved and are potentially useful to better study coupling, energy transfer, and allosteric communication in proteins.
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Affiliation(s)
- Jing Huang
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
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3
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Sun CL, Ding F, Ding YL, Li Y. The effect of water molecules upon the hydrogen-bonding cooperativity of three-stranded antiparallel β-sheet models. RSC Adv 2014. [DOI: 10.1039/c3ra45892j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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4
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Huang J, MacKerell AD. CHARMM36 all-atom additive protein force field: validation based on comparison to NMR data. J Comput Chem 2013; 34:2135-45. [PMID: 23832629 DOI: 10.1002/jcc.23354] [Citation(s) in RCA: 2241] [Impact Index Per Article: 203.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/23/2013] [Accepted: 05/26/2013] [Indexed: 11/08/2022]
Abstract
Protein structure and dynamics can be characterized on the atomistic level with both nuclear magnetic resonance (NMR) experiments and molecular dynamics (MD) simulations. Here, we quantify the ability of the recently presented CHARMM36 (C36) force field (FF) to reproduce various NMR observables using MD simulations. The studied NMR properties include backbone scalar couplings across hydrogen bonds, residual dipolar couplings (RDCs) and relaxation order parameter, as well as scalar couplings, RDCs, and order parameters for side-chain amino- and methyl-containing groups. It is shown that the C36 FF leads to better correlation with experimental data compared to the CHARMM22/CMAP FF and suggest using C36 in protein simulations. Although both CHARMM FFs contains the same nonbond parameters, our results show how the changes in the internal parameters associated with the peptide backbone via CMAP and the χ1 and χ2 dihedral parameters leads to improved treatment of the analyzed nonbond interactions. This highlights the importance of proper treatment of the internal covalent components in modeling nonbond interactions with molecular mechanics FFs.
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Affiliation(s)
- Jing Huang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn St., Baltimore, Baltimore, Maryland 21201, USA
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5
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Xue J, Burz DS, Shekhtman A. Segmental labeling to study multidomain proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 992:17-33. [PMID: 23076577 DOI: 10.1007/978-94-007-4954-2_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
This chapter contains a review of methodologies and recent applications of segmental labeling for NMR structural studies of proteins and protein complexes. Segmental labeling is used to specifically label a segment of protein structure with NMR active nuclei, thus reducing NMR spectral complexity and greatly facilitating structural NMR studies of large multi-domain proteins. It can also be used to introduce a synthetic fragment into a protein structure to study post-translationally modified proteins. Detailed protocols describing segmental labeling techniques are also included.
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Affiliation(s)
- Jing Xue
- Department of Chemistry, State University of New York, Albany, NY 12222, USA
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6
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Chen YF, Dannenberg JJ. The effect of polarization on multiple hydrogen-bond formation in models of self-assembling materials. J Comput Chem 2011; 32:2890-5. [PMID: 21717481 DOI: 10.1002/jcc.21870] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 05/01/2011] [Accepted: 05/23/2011] [Indexed: 01/27/2023]
Abstract
We report density functional theory calculations at the B3LYP/D95(d,p) level on several different cyclic H-bonding dimers, where the monomers of each are connected by a pair of N-H···O=C H-bonding interactions, and the H-bonding donors and acceptors on each monomer are separated by polarizable spacers. Depending on the structures, the individual H-bonds vary in strength (enthalpy) by over a factor of four, from 2.41 to 10.99 kcal/mol. We attribute most of the variation in interaction energies to differences in the extent of polarization due to each of the H-bonds, which can either combine constructively or destructively. The dipole-dipole interactions between the pair of H-bonds also contribute somewhat to the relative stabilities. The relevance of these results to the design of self-assembling materials is discussed.
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Affiliation(s)
- Yung-Fou Chen
- Department of Chemistry, Hunter College and the Graduate School, City University of New York, 695 Park Avenue, New York, New York 10065, USA
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7
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Jiang XN, Sun CL, Wang CS. A scheme for rapid prediction of cooperativity in hydrogen bond chains of formamides, acetamides, and N-methylformamides. J Comput Chem 2010; 31:1410-20. [PMID: 19885870 DOI: 10.1002/jcc.21426] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A scheme is proposed in this article to predict the cooperativity in hydrogen bond chains of formamides, acetamides, and N-methylformamides. The parameters needed in the scheme are derived from fitting to the hydrogen bonding energies of MP2/6-31+G** with basis set superposition error (BSSE) correction of the hydrogen bond chains of formamides containing from two to eight monomeric units. The scheme is then used to calculate the individual hydrogen bonding energies in the chains of formamides containing 9 and 12 monomeric units, in the chains of acetamides containing from two to seven monomeric units, in the chains of N-methylformamides containing from two to seven monomeric units. The calculation results show that the cooperativity predicted by the scheme proposed in this paper is in good agreement with those obtained from MP2/6-31+G** calculations by including the BSSE correction, demonstrating that the scheme proposed in this article is reasonable. Based on our scheme, a cooperativity effect of almost 240% of the dimer hydrogen bonding energy in long hydrogen bond formamide chains, a cooperativity effect of almost 190% of the dimer hydrogen bonding energy in long hydrogen bond acetamide chains, and a cooperativity effect of almost 210% of the dimer hydrogen bonding energy in long hydrogen bond N-methylformamide chains are predicted. The scheme is further applied to some heterogeneous chains containing formamide, acetamide, and N-methylformamide. The individual hydrogen bonding energies in these heterogeneous chains predicted by our scheme are also in good agreement with those obtained from Møller-Plesset calculations including BSSE correction.
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Affiliation(s)
- Xiao-Nan Jiang
- School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, People's Republic of China
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8
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Afonin AV, Vashchenko AV. Theoretical study of bifurcated hydrogen bonding effects on the 1J(N,H), 1hJ(N,H), 2hJ(N,N) couplings and 1H, 15N shieldings in model pyrroles. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2010; 48:309-317. [PMID: 20198609 DOI: 10.1002/mrc.2579] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
According to the density functional theory calculations, the X...H...N (X=N, O) intramolecular bifurcated (three-centered) hydrogen bond with one hydrogen donor and two hydrogen acceptors causes a significant decrease of the (1h)J(N,H) and (2h)J(N,N) coupling constants across the N-H...N hydrogen bond and an increase of the (1)J(N,H) coupling constant across the N-H covalent bond in the 2,5-disubstituted pyrroles. This occurs due to a weakening of the N-H...N hydrogen bridge resulting in a lengthening of the N...H distance and a decrease of the hydrogen bond angle at the bifurcated hydrogen bond formation. The gauge-independent atomic orbital calculations of the shielding constants suggest that a weakening of the N-H...N hydrogen bridge in case of the three-centered hydrogen bond yields a shielding of the bridge proton and deshielding of the acceptor nitrogen atom. The atoms-in-molecules analysis shows that an attenuation of the (1h)J(N,H) and (2h)J(N,N) couplings in the compounds with bifurcated hydrogen bond is connected with a decrease of the electron density rho(H...N) at the hydrogen bond critical point and Laplacian of this electron density nabla(2)rho(H...N). The natural bond orbital analysis suggests that the additional N-H...X interaction partly inhibits the charge transfer from the nitrogen lone pair to the sigma*(N-H) antibonding orbital across hydrogen bond weakening of the (1h)J(N,H) and (2h)J(N,N) trans-hydrogen bond couplings through Fermi-contact mechanism. An increase of the nitrogen s-character percentage of the N-H bond in consequence of the bifurcated hydrogen bonding leads to an increase of the (1)J(N,H) coupling constant across the N-H covalent bond and deshielding of the hydrogen donor nitrogen atom.
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Affiliation(s)
- Andrei V Afonin
- Institute of Chemistry, Siberian Branch of the Russian Academy of Science, Favorski St. 1, 664033 Irkutsk, Russia.
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9
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Jiang XN, Wang CS. Rapid Prediction of the Hydrogen Bond Cooperativity in N-methylacetamide Chains. Chemphyschem 2009; 10:3330-6. [DOI: 10.1002/cphc.200900591] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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10
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Juranić N, Atanasova E, Macura S, Prendergast FG. Directly observed hydrogen bonds at calcium-binding-sites of calmodulin in solution relate to affinity of the calcium-binding. J Inorg Biochem 2009; 103:1415-8. [DOI: 10.1016/j.jinorgbio.2009.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 08/14/2009] [Accepted: 08/19/2009] [Indexed: 11/24/2022]
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11
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Alkorta I, Blanco F, Elguero J. A theoretical structural analysis of the factors that affect (1)J(NH), (1h)J(NH) and (2h)J(NN) in N-H...N hydrogen-bonded complexes. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2009; 47:249-256. [PMID: 19097158 DOI: 10.1002/mrc.2382] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Calculations of (1)J(NH), (1h)J(NH) and (2h)J(NN) spin-spin coupling constants of 27 complexes presenting N-H...N hydrogen bonds have allowed to analyze these through hydrogen-bond coupling as a function of the hybridization of both nitrogen atoms and the charge (+1, 0, - 1) of the complex. The main conclusions are that the hybridization of N atom of the hydrogen bond donor is much more important than that of the hydrogen bond acceptor. Positive and negative charges (cationic and anionic complexes) exert opposite effects while the effect of the transition states 'proton-in-the-middle' is considerable.
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Affiliation(s)
- Ibon Alkorta
- Instituto de Química Médica, CSIC, Juan de la Cierva, 3, E-28006 Madrid, Spain.
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12
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Pedersoli S, Tormena CF, dos Santos FP, Contreras RH, Rittner R. Stereochemical behavior of 1JCH and 2JCH NMR coupling constants in α-substituted acetamides. J Mol Struct 2008. [DOI: 10.1016/j.molstruc.2008.04.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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13
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Alkorta I, Elguero J, Denisov GS. A review with comprehensive data on experimental indirect scalar NMR spin-spin coupling constants across hydrogen bonds. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:599-624. [PMID: 18357569 DOI: 10.1002/mrc.2209] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Scalar NMR spin-spin coupling constants across hydrogen bonds are fundamental in structural studies and as test grounds for theoretical calculations. Since they are scattered among many articles of different kinds, it seems useful to collect them in the most comprehensive way.
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Affiliation(s)
- Ibon Alkorta
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain.
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14
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Giribet CG, Azúa MCRD. CLOPPA-IPPP analysis of cooperative effects in hydrogen-bonded molecular complexes. Application to intermolecular 2hJ(N,C) spin-spin coupling constants in linear (CNH)n complexes. J Phys Chem A 2008; 112:4386-93. [PMID: 18410158 DOI: 10.1021/jp712113y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The cooperative effects on NMR indirect nuclear coupling constants are analyzed by means of the IPPP-CLOPPA approach (where CLOPPA is the Contributions from Localized Orbitals within the Polarization Propagator Approach and IPPP is the Inner Projections of the Polarization Propagator). The decomposition of the J coupling allows one to classify these effects as those due to changes in the geometric structure and those that directly involve the transmission mechanisms. This latter contribution admits a further classification, taking into account its electronic origin. As an example, the cooperative effects on intermolecular 2hJ(N,C) couplings of the linear complexes (CNH)n (n = 2, 3, 4) are discussed.
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Affiliation(s)
- Claudia G Giribet
- Department of Physics, Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Ciudad Universitaria, Pab. I, (1428) Buenos Aires, Argentina. giribet@ df.uba.ar
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15
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Del Bene JE, Alkorta I, Elguero J. Spin-spin coupling across intramolecular N-H(+)-N hydrogen bonds in models for proton sponges: an ab initio investigation. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:457-463. [PMID: 18297741 DOI: 10.1002/mrc.2199] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Ab initio calculations have been performed to obtain structures and coupling constants (1)J(N-H), (1h)J(H-N), and (2h)J(N-N) for models of proton sponges with symmetric and asymmetric N-H(+)-N intramolecular hydrogen bonds (IMHBs). For a given model, the asymmetric structure has a lower energy, a longer N-N distance, and a hydrogen bond which has a greater deviation from linearity. The computed values of (2h)J(N-N) for the models are significantly less than predicted values based on the distance dependence of (2h)J(N-N) for complexes with intermolecular N-H(+)-N hydrogen bonds. However, the reduced values of (2h)J(N-N) cannot be attributed solely to the distortion of the hydrogen bond in the models, but also reflect differences in s electron populations at the nitrogens in both the ground state and the excited states which couple to it through the Fermi-contact (FC) operator. Values of (2h)J(N-N) for IMHBs can be related quadratically to the N-N distances in the models, and demonstrate that there is no discrepancy between computed values of (2h)J(N-N) at the short N-N distances found in these systems and experimental data for proton sponges.
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Affiliation(s)
- Janet E Del Bene
- Department of Chemistry, Youngstown State University, Youngstown, Ohio 44555, USA.
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16
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Juranić N, Dannenberg JJ, Cornilescu G, Salvador P, Atanasova E, Ahn HC, Macura S, Markley JL, Prendergast FG. Structural dependencies of protein backbone 2JNC' couplings. Protein Sci 2008; 17:768-76. [PMID: 18305196 DOI: 10.1110/ps.073331608] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Protein folding can introduce strain in peptide covalent geometry, including deviations from planarity that are difficult to detect, especially for a protein in solution. We have found dependencies in protein backbone (2)J(NC') couplings on the planarity and the relative orientation of the sequential peptide planes. These dependences were observed in experimental (2)J(NC') couplings from seven proteins, and also were supported by DFT calculations for a model tripeptide. Findings indicate that elevated (2)J(NC') couplings may serve as reporters of structural strain in the protein backbone imposed by protein folds. Such information, supplemented with the H-bond strengths derived from (h3)J(NC') couplings, provides useful insight into the overall energy profile of the protein backbone in solution.
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Affiliation(s)
- Nenad Juranić
- Department of Biochemistry and Molecular Biology, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA
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17
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Abstract
Density functional theory calculations were used to examine the effect of H-bond cooperativity on the magnitude of the NMR chemical shifts and spin-spin coupling constants in a C4h-symmetric G-quartet and in structures consisting of six cyanamide monomers. These included two ring structures (a planar C6h-symmetric structure and a nonplanar S6-symmetric structure) and two linear chain structures (a fully optimized planar Cs-symmetric chain and a planar chain structure where all intra- and intermolecular parameters were constrained to be identical). The NMR parameters were computed for the G-quartet and cyanamide structures, as well as for shorter fragments derived from these assemblies without reoptimization. In the ring structures and the chain with identical monomers, the intra- and intermolecular geometries of the cyanamides were identical, thereby allowing the study of cooperative effects in the absence of geometry changes. The magnitude of the |1JNH| coupling, 1H and 15N chemical shifts of the H-bonding amino N-H group, and the |h2JNN| H-bond coupling increased, whereas the size of the |1JNH| coupling of the non-H-bonded amino N-H bonds of the first amino group in the chain, which are roughly perpendicular to the H-bonding network, decreased in magnitude when H-bonding monomers were progressively added to extending ring or chain structures. These effects are attributed to electron redistribution induced by the presence of the nearby H-bonding guanine or cyanamide molecules.
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Affiliation(s)
- Tanja van Mourik
- Chemistry Department, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
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Juranić N, Atanasova E, Streiff JH, Macura S, Prendergast FG. Solvent-induced differentiation of protein backbone hydrogen bonds in calmodulin. Protein Sci 2007; 16:1329-37. [PMID: 17567747 PMCID: PMC2206704 DOI: 10.1110/ps.062689807] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 02/18/2007] [Accepted: 02/23/2007] [Indexed: 10/23/2022]
Abstract
In apo and holoCaM, almost half of the hydrogen bonds (H-bonds) at the protein backbone expected from the corresponding NMR or X-ray structures were not detected by h3JNC' couplings. The paucity of the h3JNC' couplings was considered in terms of dynamic features of these structures. We examined a set of seven proteins and found that protein-backbone H-bonds form two groups according to the h3JNC' couplings measured in solution. H-bonds that have h3JNC' couplings above the threshold of 0.2 Hz show distance/angle correlation among the H-bond geometrical parameters, and appear to be supported by the backbone dynamics in solution. The other H-bonds have no such correlation; they populate the water-exposed and flexible regions of proteins, including many of the CaM helices. The observed differentiation in a dynamical behavior of backbone H-bonds in apo and holoCaM appears to be related to protein functions.
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Affiliation(s)
- Nenad Juranić
- Department of Biochemistry and Molecular Biology, Mayo College of Medicine, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
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Salvador P, Wieczorek R, Dannenberg JJ. Direct Calculation of trans-Hydrogen-Bond 13C-15N 3-Bond J-Couplings in Entire Polyalanine α-Helices. A Density Functional Theory Study. J Phys Chem B 2007; 111:2398-403. [PMID: 17295533 DOI: 10.1021/jp064706c] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present the first trans-H-bond 13C-15N 3-bond J couplings calculated from entire neutral and protonated alpha-helical polyalanines. The neutral helices considered are those of the capped peptides, acetyl(Ala)NNH2, where N = 8, 16, 17, and 18, while the protonated peptides are the uncapped (Ala)17 protonated at three different positions. The calculated J values correlate well with O...H distances and somewhat less well with N...O distances, particularly if the terminal H-bonds are eliminated from the correlation. The J values calculated using the entire helix are about 6% lower in magnitude than those recently reported for H-bonding chains whose geometries were extracted from the same helices. Aqueous solvation favors protonation of the alpha-helix on the terminal COOH. Experimental measurements of the trans-H-bond 13C-15N 3-bond J couplings in acidic solution should be interpreted with this context.
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Affiliation(s)
- Pedro Salvador
- Department of Chemistry, City University of New York--Hunter College and the Graduate School, 695 Park Avenue, New York, New York 10021, USA
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20
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van Mourik T. Density functional theory reveals an increase in the amino H1 chemical shift in guanine due to hydrogen bonding with water. J Chem Phys 2006; 125:191101. [PMID: 17129081 DOI: 10.1063/1.2400028] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Electronic structure calculations underestimate the chemical shift of the non H-bonded amino proton 1H22 in isolated G-quartet structures. The current work shows that this underestimation is due to the absence of a water environment in the calculations: coordination of at least two water molecules is required to obtain good agreement with experiment. The results indicate how improved agreement between calculated and experimental (solution-phase) NMR data can be obtained.
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Affiliation(s)
- Tanja van Mourik
- Chemistry Department, University College London, London WC1H 0AJ, United Kingdom.
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van Mourik T, Dingley AJ. Characterization of the monovalent ion position and hydrogen-bond network in guanine quartets by DFT calculations of NMR parameters. Chemistry 2006; 11:6064-79. [PMID: 16052652 DOI: 10.1002/chem.200500198] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Conformational stability of G-quartets found in telomeric DNA quadruplex structures requires the coordination of monovalent ions. Here, an extensive Hartree-Fock and density functional theory analysis of the energetically favored position of Li+, Na+, and K+ ions is presented. The calculations show that at quartet-quartet distances observed in DNA quadruplex structures (3.3 A), the Li+ and Na+ ions favor positions of 0.55 and 0.95 A outside the plane of the G-quartet, respectively. The larger K+ ion prefers a central position between successive G-quartets. The energy barrier separating the minima in the quartet-ion-quartet model are much smaller for the Li+ and Na+ ions compared with the K+ ion; this suggests that K+ ions will not move as freely through the central channel of the DNA quadruplex. Spin-spin coupling constants and isotropic chemical shifts in G-quartets extracted from crystal structures of K+- and Na+-coordinated DNA quadruplexes were calculated with B3LYP/6-311G(d). The results show that the sizes of the trans-hydrogen-bond couplings are influenced primarily by the hydrogen bond geometry and only slightly by the presence of the ion. The calculations show that the R(N2N7) distance of the N2-H2...N7 hydrogen bond is characterized by strong correlations to both the chemical shifts of the donor group atoms and the (h2)J(N2N7) couplings. In contrast, weaker correlations between the (h3)J(N1C6') couplings and single geometric factors related to the N1-H1...O6=C6 hydrogen bond are observed. As such, deriving geometric information on the hydrogen bond through the use of trans-hydrogen-bond couplings and chemical shifts is more complex for the N1-H1...O6=C6 hydrogen bond than for the N2-H2...N7 moiety. The computed trans-hydrogen-bond couplings are shown to correlate with the experimentally determined couplings. However, the experimental values do not show such strong geometric dependencies.
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Affiliation(s)
- Tanja van Mourik
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
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Ahn HC, Jurani N, Macura S, Markley JL. Three-dimensional structure of the water-insoluble protein crambin in dodecylphosphocholine micelles and its minimal solvent-exposed surface. J Am Chem Soc 2006; 128:4398-404. [PMID: 16569017 PMCID: PMC2533276 DOI: 10.1021/ja057773d] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We chose crambin, a hydrophobic and water-insoluble protein originally isolated from the seeds of the plant Crambe abyssinica, as a model for NMR investigations of membrane-associated proteins. We produced isotopically labeled crambin(P22,L25) (variant of crambin containing Pro22 and Leu25) as a cleavable fusion with staphylococcal nuclease and refolded the protein by an approach that has proved successful for the production of proteins with multiple disulfide bonds. We used NMR spectroscopy to determine the three-dimensional structure of the protein in two membrane-mimetic environments: in a mixed aqueous-organic solvent (75%/25%, acetone/water) and in DPC micelles. With the sample in the mixed solvent, it was possible to determine (>NH...OC<) hydrogen bonds directly by the detection of (h3)J(NC)' couplings. H-bonds determined in this manner were utilized in the refinement of the NMR-derived protein structures. With the protein in DPC (dodecylphosphocholine) micelles, we used manganous ion as an aqueous paramagnetic probe to determine the surface of crambin that is shielded by the detergent. With the exception of the aqueous solvent exposed loop containing residues 20 and 21, the protein surface was protected by DPC. This suggests that the protein may be similarly embedded in physiological membranes. The strategy described here for the expression and structure determination of crambin should be applicable to structural and functional studies of membrane active toxins and small membrane proteins.
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Affiliation(s)
- Hee-Chul Ahn
- National Magnetic Resonance Facility at Madison, Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706-1544, USA,
| | - Nenad Jurani
- Departments of Biochemistry and Molecular Biology, Mayo College of Medicine, Mayo Clinic and Foundation, Rochester, Minnesota, 55905 USA
| | - Slobodan Macura
- Departments of Biochemistry and Molecular Biology, Mayo College of Medicine, Mayo Clinic and Foundation, Rochester, Minnesota, 55905 USA
| | - John L. Markley
- National Magnetic Resonance Facility at Madison, Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706-1544, USA,
- Corresponding author: John L. Markley, Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Dr., Madison, WI 53706, USA, Phone: 1-608-263-9349, Fax: 1-608-262-3759,
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23
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Juranić N, Atanasova E, Moncrieffe MC, Prendergast FG, Macura S. Calcium-binding proteins afford calibration of dihedral-angle dependence of 3J(NC(gamma)) coupling constant in aspartate and asparagine residues. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2005; 175:222-5. [PMID: 15907387 DOI: 10.1016/j.jmr.2005.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2005] [Revised: 04/08/2005] [Accepted: 04/16/2005] [Indexed: 05/02/2023]
Abstract
Calibration of the 3J(NC(gamma)) couplings across the N-C(alpha)-C(beta)-C(gamma) fragment of aspartate and asparagine residues is afforded by two interactions that produce fixed conformations of the side chains in solution. One is the binding of these side chains to calcium ions; the other is the H-bond interaction of these side chains with a backbone amide.
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Affiliation(s)
- Nenad Juranić
- Department of Biochemistry and Molecular Biology, Mayo College of Medicine, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
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24
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Salvador P, Kobko N, Wieczorek R, Dannenberg JJ. Calculation of trans-hydrogen-bond 13C-15N three-bond and other scalar J-couplings in cooperative peptide models. A density functional theory study. J Am Chem Soc 2004; 126:14190-7. [PMID: 15506785 DOI: 10.1021/ja0492788] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report B3LYP DFT calculations on peptide models that consider the effects of cooperative interactions with proximate H-bonds and local geometry at the H-bonding site upon trans-H-bond (13)C-(15)N three-bond scalar J-couplings. The calculations predict that cooperative interactions with other H-bonds within a H-bonding chain can significantly increase the magnitude of these couplings. Such increases are due to a combination of the presence of the neighboring H-bonds and the slight increase in C=O distances expected for peptide H-bonds near the centers of H-bonding chains. The energies of H-bonds inferred from H-bonding distances, alone, could be significantly in error if the effects of neighboring H-bonds are ignored.
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Affiliation(s)
- Pedro Salvador
- Department of Chemistry, City University of New York - Hunter College and the Graduate School, 695 Park Avenue, New York, New York 10021, USA
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25
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Viswanathan R, Asensio A, Dannenberg JJ. Cooperative Hydrogen-Bonding in Models of Antiparallel β-Sheets. J Phys Chem A 2004. [DOI: 10.1021/jp047404o] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Raji Viswanathan
- Department of Chemistry, City University of New York - Hunter College and The Graduate School, 695 Park Avenue, New York, New York 10021
| | - Amparo Asensio
- Department of Chemistry, City University of New York - Hunter College and The Graduate School, 695 Park Avenue, New York, New York 10021
| | - J. J. Dannenberg
- Department of Chemistry, City University of New York - Hunter College and The Graduate School, 695 Park Avenue, New York, New York 10021
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26
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Salvador P, Dannenberg JJ. Dependence upon Basis Sets of trans Hydrogen-Bond 13C−15N 3-Bond and Other Scalar J-Couplings in Amide Dimers Used as Peptide Models. A Density Functional Theory Study. J Phys Chem B 2004. [DOI: 10.1021/jp0480955] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pedro Salvador
- Department of Chemistry and Biochemistry, City University of New York - Hunter College and the Graduate School, 695 Park Avenue, New York, New York 10021
| | - J. J. Dannenberg
- Department of Chemistry and Biochemistry, City University of New York - Hunter College and the Graduate School, 695 Park Avenue, New York, New York 10021
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27
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Tomić Z, Novaković S, Zarić S. Intermolecular Interactions between Chelate Rings and Phenyl Rings in Square-Planar Copper(II) Complexes. Eur J Inorg Chem 2004. [DOI: 10.1002/ejic.200400086] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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28
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Shenkarev ZO, Balashova TA, Yakimenko ZA, Ovchinnikova TV, Arseniev AS. Peptaibol zervamicin IIb structure and dynamics refinement from transhydrogen bond J couplings. Biophys J 2004; 86:3687-99. [PMID: 15189865 PMCID: PMC1304270 DOI: 10.1529/biophysj.103.036798] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2003] [Accepted: 03/05/2004] [Indexed: 11/18/2022] Open
Abstract
Zervamicin IIB (Zrv-IIB) is a channel-forming peptaibol antibiotic of fungal origin. The measured transhydrogen bond (3h)J(NC') couplings in methanol solution heaving average value of -0.41 Hz indicate that the stability of the Zrv-IIB helix in this milieu is comparable to the stability of helices in globular proteins. The N-terminus of the peptide forms an alpha-helix, whereas 3(10)-helical hydrogen bonds stabilize the C-terminus. However, two weak transhydrogen bond peaks are observed in a long-range HNCO spectrum for HN Aib(12). Energy calculations using the Empirical Conformation Energy Program for Peptides (ECEPP)/2 force field and the implicit solvent model show that the middle of the peptide helix accommodates a bifurcated hydrogen bond that is simultaneously formed between HN Aib(12) and CO Leu(8) and CO Aib(9). Several lowered (3h)J(NC') on a polar face of the helix correlate with the conformational exchange process observed earlier and imply dynamic distortions of a hydrogen bond pattern with the predominant population of a properly folded helical structure. The refined structure of Zrv-IIB on the basis of the observed hydrogen bond pattern has a small ( approximately 20 degrees ) angle of helix bending that is virtually identical to the angle of bending in dodecylphosphocholine (DPC) micelles, indicating the stability of a hinge region in different environments. NMR parameters ((1)HN chemical shifts and transpeptide bond (1)J(NC') couplings) sensitive to hydrogen bonding along with the solvent accessible surface area of carbonyl oxygens indicate a large polar patch on the convex side of the helix formed by three exposed backbone carbonyls of Aib(7), Aib(9), and Hyp(10) and polar side chains of Hyp(10), Gln(11), and Hyp(13). The unique structural features, high helix stability and the enhanced polar patch, set apart Zrv-IIB from other peptaibols (for example, alamethicin) and possibly underlie its biological and physiological properties.
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Affiliation(s)
- Z O Shenkarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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29
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Romanelli A, Shekhtman A, Cowburn D, Muir TW. Semisynthesis of a segmental isotopically labeled protein splicing precursor: NMR evidence for an unusual peptide bond at the N-extein-intein junction. Proc Natl Acad Sci U S A 2004; 101:6397-402. [PMID: 15087498 PMCID: PMC404056 DOI: 10.1073/pnas.0306616101] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protein splicing is a posttranslational autocatalytic process in which an intervening sequence, termed an intein, is removed from a host protein, the extein. Although we have a reasonable picture of the basic chemical steps in protein splicing, our knowledge of how these are catalyzed and regulated is less well developed. In the current study, a combination of NMR spectroscopy and segmental isotopic labeling has been used to study the structure of an active protein splicing precursor, corresponding to an N-extein fusion of the Mxe GyrA intein. The (1)J(NC') coupling constant for the (-1) scissile peptide bond at the N-extein-intein junction was found to be approximately 12 Hz, which indicates that this amide is highly polarized, perhaps because of nonplanarity. Additional mutagenesis and NMR studies indicate that conserved box B histidine residue is essential for catalysis of the first step of splicing and for maintaining the (-1) scissile bond in its unusual conformation. Overall, these studies support the "ground-state destabilization" model as part of the mechanism of catalysis.
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Affiliation(s)
- Alessandra Romanelli
- Laboratory of Synthetic Protein Chemistry, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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30
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Tuttle T, Kraka E, Wu A, Cremer D. Investigation of the NMR Spin−Spin Coupling Constants across the Hydrogen Bonds in Ubiquitin: The Nature of the Hydrogen Bond as Reflected by the Coupling Mechanism. J Am Chem Soc 2004; 126:5093-107. [PMID: 15099092 DOI: 10.1021/ja030246e] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The indirect scalar NMR spin-spin coupling constants across the H-bonds of the protein ubiquitin were calculated, including the Fermi contact, the diamagnetic spin-orbit, the paramagnetic spin-orbit, and the spin dipole term, employing coupled perturbed density functional theory in combination with the B3LYP functional and different basis sets: (9s,5p,1d/5s,1p)[6s,4p,1d/3s,1p] and (11s,7p,2d/5s,1p)[7s,6p,2d/4s,2p]. Four different models based on either the crystal or the aqueous solution structure of ubiquitin were used to describe H-bonding for selected residue pairs of ubiquitin. Calculated and measured 3hJ(NC') coupling constants differ depending on the model used, which is due to the fact that the geometry of ubiquitin is different in the solid state and in aqueous solution. Also, conformational averaging leads to a decrease of the magnitude of the measured 3hJ(NC') constants, which varies locally (larger for -sheets, smaller for -helix). Two different spin-spin coupling mechanisms were identified. While mechanism I transmits spin polarization via an electric field effect, mechanism II involves also electron delocalization from the lone pair of the carbonyl oxygen to the antibonding orbital of the N-H bond. Mechanism I is more important in the crystal structure of ubiquitin, while in aqueous solution, mechanism II plays a larger role. It is possible to set up simple relationships between the spin-spin coupling constants associated with the H bond in proteins and the geometrical features of these bonds. The importance of the 3hJ(NC') and 1J(N-H) constants as descriptors for the H-bond is emphasized.
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Affiliation(s)
- Tell Tuttle
- Department of Theoretical Chemistry, Göteborg University, Sweden
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31
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Ilich P, Juranić N. One-Bond 15N13C′ Nuclear Spin-Spin Coupling in N-Methylacetamide: a Model for Hydrogen-Bonded Peptides. Chemphyschem 2003; 4:1358-60. [PMID: 14714388 DOI: 10.1002/cphc.200300647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Predrag Ilich
- Department of Chemistry & Biochemistry, Loras College Dubuque, IA 52001, USA.
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32
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Juranić N, Macura S, Prendergast FG. H-bonding mediates polarization of peptide groups in folded proteins. Protein Sci 2003; 12:2633-6. [PMID: 14573874 PMCID: PMC2366962 DOI: 10.1110/ps.03127103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2003] [Revised: 06/04/2003] [Accepted: 06/18/2003] [Indexed: 10/26/2022]
Abstract
The carbon-nitrogen J-couplings in the hydrogen bonding chains of proteins show that H-bonding mediates peptide-group polarization, which results in the general reduction of peptide-group polarity of folded proteins in solution. The net effect is to make large regions of protein secondary structure, especially beta-sheets, intrinsically more hydrophobic, contributing thereby to overall stability of the tertiary structure.
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Affiliation(s)
- Nenad Juranić
- Department of Biochemistry and Molecular Biology, Mayo Graduate School, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
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33
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Moisan S, Dannenberg JJ. Molecular Orbital Calculations on the Protonation of Hydrogen-Bonded Formamide Chains. Implications for Peptides. J Phys Chem B 2003. [DOI: 10.1021/jp035791g] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sandy Moisan
- Department of Chemistry, City University of New YorkHunter College and The Graduate School, 695 Park Avenue, New York, New York 10021
| | - J. J. Dannenberg
- Department of Chemistry, City University of New YorkHunter College and The Graduate School, 695 Park Avenue, New York, New York 10021
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