@article {418,
	title = {Determination of dihedral angles in peptides through experimental and theoretical studies of alpha-carbon chemical shielding tensors},
	journal = {Journal of the American Chemical Society},
	volume = {119},
	year = {1997},
	note = {J Am Chem SocXt037Times Cited:90Cited References Count:57},
	month = {Aug 20},
	pages = {7827-7831},
	abstract = {<p>A simple method for the determination of backbone dihedral angles in peptides and proteins is presented. The chemical-shift anisotropies (CSA) of the central alanine alpha-carbon in powdered crystalline tripeptides, whose structures have been determined previously by X-ray crystallography, were measured by cross-polarization magic-angle-spinning nuclear magnetic resonance. The experimental CSA values were correlated with ab initio chemical-shielding calculations over Ramanchandran phi/psi space on an N-formyl-L-alanine amide fragment. Using this correlation, phi/psi probability surfaces for one of the tripeptides were calculated based only on the alpha-carbon CSA, allowing a prediction of backbone angles. Dihedral angles predicted by these calculations fall within +/-12 degrees of the values determined by crystallography. This approach should be useful in the determination of solid-slate protein structure.</p>
},
	keywords = {crystal-structure},
	isbn = {0002-7863},
	doi = {Doi 10.1021/Ja970124k},
	url = {<Go to ISI>://WOS:A1997XT03700025},
	author = {Heller, J. and Laws, D. D. and Tomaselli, M. and King, D. S. and Wemmer, D. E. and Pines, A. and Havlin, R. H. and Oldfield, E.}
}
