Energy parameters in polypeptides. 10. Improved geometrical parameters and nonbonded interactions for use in the ECEPP/3 algorithm, with application to proline-containing peptides

George Némethy, Kenneth D. Gibson, Kathleen A. Palmer, Chang No Yoon, Germana Paterlini, Adriana Zagari, Shirley Rumsey, Harold A. Scheraga*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

638 Scopus citations

Abstract

Some of the parameters that are used in the computer program ECEPP (Empirical Conformational Energy Program for Peptides) to describe the geometry of amino acid residues and the potential energy of interactions have been updated. The changes are based on recently available experimental information. The most significant changes improve the geometry and the interactions of prolyl and hydroxyprolyl residues, on the basis of crystallographic structural data. The structure of the pyrrolidine ring has been revised to correspond to the experimentally determined extent of out-of-plane puckering of the five-membered ring. The geometry of the peptide group preceding a Pro residue has also been altered. The parameters for nonbonded interactions involving the Cδ and Hδ atoms of Pro and Hyp have been modified. Use of the revised parameters provides improvements in the computed minimum-energy conformations of peptides containing the Pro-Pro and Ala-Pro sequences. In particular, it is demonstrated that an α-helix-like conformation of a residue preceding Pro is now only of moderately high energy, and thus it is an accessible state. This result corroborates the observed occurrence of Pro residues in kinked α-helices in globular proteins. The structure of the poly(Gly-Pro-Pro) triple helix, a computational model for collagen structure, has been recomputed. The validity of previous computations for this model structure has been confirmed. The refinement of the computed interactions has provided a new general model structure to be used for future computations on collagen-like polypeptides.

Original languageEnglish
Pages (from-to)6472-6484
Number of pages13
JournalJournal of Physical Chemistry
Volume96
Issue number15
DOIs
StatePublished - 1992
Externally publishedYes

Fingerprint

Dive into the research topics of 'Energy parameters in polypeptides. 10. Improved geometrical parameters and nonbonded interactions for use in the ECEPP/3 algorithm, with application to proline-containing peptides'. Together they form a unique fingerprint.

Cite this