Premium
Theoretical structure of the polar regions of the tropocollagen molecule
Author(s) -
Hopfingkr A. J.,
Walton A. G.
Publication year - 1970
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.1970.360090406
Subject(s) - polyproline helix , chemistry , molecule , polar , glycine , triple helix , peptide , sequence (biology) , crystallography , stereochemistry , collagen helix , biophysics , amino acid , biochemistry , physics , organic chemistry , astronomy , biology
The theoretical conformations of poly (Gly‐Ala‐Glu) have been studied. This peptide was chosen as a model for the glycine led triads of the polar regions in collagen. The most favorable conformations are found to be based on the extended and folded forms of the 2 7 helix (2 7a and 2 7b ). It is suggested that triple‐strand structures of folded 2 7 helices exist in the polar collagen regions, and a structural model is presented which is in accord with recent ultrastructural deformation studies. It is a necessary condition for this structure that glycine occur in the lead of the peptide triads. In regions of the collagen molecule where the primary sequence does not contain triads (e.g., in the telopeptide region), random structures based on energy minimization of peptide neighbors are considered briefly. It seems likely that such regions contain an admixture of left‐hand α, polyproline II, and 2 7 helix structures.