Premium
Toward direct determination of conformations of protein building units from multidimensional NMR experiments I. A theoretical case study of For‐Gly‐NH 2 and For‐ L ‐Ala‐NH 2
Author(s) -
Perczel András,
Császár Attila G.
Publication year - 2000
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/1096-987x(20000730)21:10<882::aid-jcc6>3.0.co;2-a
Subject(s) - chemical shift , chemistry , conformational isomerism , amide , heteronuclear single quantum coherence spectroscopy , anisotropy , computational chemistry , nuclear magnetic resonance , molecule , two dimensional nuclear magnetic resonance spectroscopy , stereochemistry , physics , quantum mechanics , organic chemistry
NMR chemical shielding anisotropy tensors have been computed, employing several basis sets and the GIAO‐RHF and GIAO‐MP2 formalisms of electronic structure theory, for all the atoms of the five and nine typical backbone conformers of For‐Gly‐NH 2 and For‐ L ‐Ala‐NH 2 , respectively. Multidimensional chemical shift plots, as a function of the respective backbone fold, have been generated for both peptide models. On the 2D 1 H NH ‐ 15 N NH and 15 N NH ‐ 13 C α plots the most notable feature is that at all levels of theory studied the backbone conformers cluster in different regions. Computed chemical shifts, as well as their averages, have been compared to relevant experimental values taken from the BioMagnetic Resonance Bank (BMRB). At the highest levels of theory, for all nuclei but the amide protons, deviations between statistically averaged theoretical and experimental shifts are as low as 1–3%. These results indicate that chemical shift information from selected multiple‐pulse NMR experiments (e.g., 2D‐HSQC and 3D‐HNCA) could directly be employed to extract folding information for polypeptides and proteins. © 2000 John Wiley & Sons, Inc. J Comput Chem 21: 882–900, 2000