Role of non-planar peptide unit in regular polypeptide helices. New model for poly-beta-benzyl-L-Aspartate.
The effect of non-planarity of the peptide unit on helical structures stabilized by intrachain hydrogen bonds is discussed. While the present calculations generally agree with those already reported in the literature for right-handed helical structures, it is found that the most stable left-handed structure is a novel helix, called the delta-helix. Its helical parameters are close to these reported for poly-beta-benzyl-L -aspartate. Conformational energy calculations show that poly-beta-benzyl-L -aspartate with the delta-helical structure is considerably more stable than the structure it is generally believed to take up (the omega-helix) by about 15 kcal/mol-residue.
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006860:Hydrogen Bonding; D046911:Macromolecular Substances; D008956:Models, Chemical; D010455:Peptides; D011487:Protein Conformation
D046911:Macromolecular Substances; D010455:Peptides; C033141:poly-beta-benzyl-aspartate