Chemical-shift ranges in proteins

Augspurger, Joseph D.; Pearson, John G.; Oldfield, Eric; Dykstra, Clifford E.; Park, Ki Deok; Schwartz, Dwight

doi:10.1016/0022-2364(92)90267-b

Cited by 46 publications

(64 citation statements)

References 49 publications

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“…The influence of a uniform electric field (E) on the shielding tensor r ab (a, b = x, y, z) was been described originally by Stephen [229] and Buckingham [230]. Intramolecular electric fields are usually not uniform; therefore, the effects of electric field gradients have also to be taken into account [191,227,231]:…”

Section: Inter-molecular Electric Field Effectsmentioning

confidence: 99%

“…The charge field perturbation (CFP) approach [225,226] consists of adding a one-electron operator to the molecular electronic Hamiltonian to represent an exter- Table 9 Comparison of experimental a and calculated absolute 17 O shielding tensor components (r xx , r yy , r zz ), shielding anisotropy (Dr), and isotropic shielding, r iso , for the CO molecule and group 6 metal carbonyls (numbers in ppm) [ nal electric multipole. The second procedure, termed the multipole shielding polarizability (MSP) approach [227,228], will be discussed below. The influence of a uniform electric field (E) on the shielding tensor r ab (a, b = x, y, z) was been described originally by Stephen [229] and Buckingham [230].…”

Section: Inter-molecular Electric Field Effectsmentioning

confidence: 99%

See 1 more Smart Citation

Oxygen-17 NMR spectroscopy: Basic principles and applications (Part I)

Gerothanassis

2010

Progress in Nuclear Magnetic Resonance Spectroscopy

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107

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Section: Inter-molecular Electric Field Effectsmentioning

confidence: 99%

Section: Inter-molecular Electric Field Effectsmentioning

confidence: 99%

Oxygen-17 NMR spectroscopy: Basic principles and applications (Part I)

Gerothanassis

2010

Progress in Nuclear Magnetic Resonance Spectroscopy

123

107

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“…From the modelling of protein NMR it is known that the sort of fields experienced in the equilibrium environment are on average 0.006 au rising to 0.008 au for the more perturbed atoms [7,8] (1 au = 5.14220 x 10 11 V m -1 ). It is clear that the model here requires a field of about a half to one orders of magnitude greater than these equilibrium fields to put in as much energy as the bond energy.…”

Section: Electrical Strain In a Simple Modelmentioning

confidence: 99%

<b>Towards a generic model of catalysis</b>

Grayson¹,

Janusz²

2008

Bull. Chem. Soc. Eth.

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ABSTRACT. A generic method of modelling catalysis using fundamental experimental bond based data is described. This model is a form of electrostatically driven catalysis which has some considerable literature. It is proposed that it can be used in conjunction with molecular modelling visualization tools. Chemical concepts are applied without direct calculation of any electronic structure. Related to the electrically distorted bond model however is the geometrical distortion which forms the basis of the entasis effect. The current state of modelling entasis is reviewed but the model calculations presented here are of the electrical strain induced in a molecule prior to reaching the transition state. We consider polarizabilities and hardness/softness parameters to see how local polarizations of the electron density may also be responsible for activation of a localised area of a large molecule.

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“…The shift effects were found to be large at plausible intermolecular distances, and the results of the supermolecule and point charge/point dipole calculations agreed. In addition, a third method was developed, in which the derivatives of the shielding tensor with respect to the field ðÃÞ and field gradient ðBÞ were evaluated, by using derivative Hartree-Fock theory Augspurger et al 1992). For example, the response of the shift to a uniform field is given bỹ…”

Section: The Chemical Shift In Nmr Spectroscopymentioning

confidence: 99%

Quantum chemical studies of protein structure

Oldfield

2004

Phil. Trans. R. Soc. B

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Quantum chemical methods now permit the prediction of many spectroscopic observables in proteins and related model systems, in addition to electrostatic properties, which are found to be in excellent accord with those determined from experiment. I discuss the developments over the past decade in these areas, including predictions of nuclear magnetic resonance chemical shifts, chemical shielding tensors, scalar couplings and hyperfine (contact) shifts, the isomer shifts and quadrupole splittings in Mö ssbauer spectroscopy, molecular energies and conformations, as well as a range of electrostatic properties, such as charge densities, the curvatures, Laplacians and Hessians of the charge density, electrostatic potentials, electric field gradients and electrostatic field effects. The availability of structure/spectroscopic correlations from quantum chemistry provides a basis for using numerous spectroscopic observables in determining aspects of protein structure, in determining electrostatic properties which are not readily accessible from experiment, as well as giving additional confidence in the use of these techniques to investigate questions about chemical bonding and chemical reactions.

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Chemical-shift ranges in proteins

Cited by 46 publications

References 49 publications

Oxygen-17 NMR spectroscopy: Basic principles and applications (Part I)

Oxygen-17 NMR spectroscopy: Basic principles and applications (Part I)

<b>Towards a generic model of catalysis</b>

Quantum chemical studies of protein structure

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