title: SCF-MO study of the polyglycine II structure.
abstract: In order to get insight into the conditions that make polyglycine (PG)II a stable structure, the conformational features of three model molecules closely related to the PGII conformation were investigated. The model molecules selected were glycine dipeptide (AGN), glycine tripeptide (AGGN), and glycine tetrapeptide (AGGGN). Environmental effects were mimicked by means of formaldehyde molecules. The calculations were carried out at the SCF semiempirical level, using the AM1 method. The calculations show that of the three systems considered, only the AGGGN molecule presents a minimum energy conformation which corresponds to a PGII structure. The environmental conditions in which this conformation is found were also analyzed.
authors.affiliation: Department d'Enginyeria Quimica, UPC, E.T.S. d'Enginyers Industrials, Barcelona, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Alemán
authors.forename: J J
authors.initials: JJ
authors.lastname: Perez
mesh_terms: D000595:Amino Acid Sequence; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004151:Dipeptides / Q000737:chemistry; D005557:Formaldehyde / Q000737:chemistry; D005998:Glycine / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*
chemical_list: D004151:Dipeptides; D010455:Peptides; D005557:Formaldehyde; C011080:polyglycine; D005998:Glycine