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Prediction of fluorine chemical shifts in proteins
Author(s) -
Gregory D. H.,
Gerig J. T.
Publication year - 1991
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360310705
Subject(s) - chemistry , van der waals force , fluorine , chemical physics , electromagnetic shielding , chemical shift , molecular dynamics , computational chemistry , force field (fiction) , aqueous solution , anisotropy , crystallography , molecule , organic chemistry , quantum mechanics , physics
Molecular dynamics calculations have been used in an effort to estimate the change in fluorine nmr shielding when a fluorine nucleus enters the tertiary structure of a protein. Considerations of the possible interactions that can define the shift parameter change suggest that van der Waals interactions are the leading determinant of fluorine shifts in proteins, although aromatic ring currents, other magnetic anisotropies, and electrostatic field effects could result in shift distinctions of 1 ppm or smaller. Results of our studies of a fluorine‐containing analogue of the ribonuclease A S‐protein/S‐peptide complex indicate that static structures such as those implied by crystallographic data lead to overestimates of the magnitude of the van der Waals shielding term; molecular dynamics simulations provide indications of the effects of conformational averaging in defining this term. The treatment used predicts the correct direction of the shift change when the fluorine enters this protein environment from aqueous solution and, with an experimentally supported choice of adjustable parameters, gives agreement with the magnitude of the shift.