title: The effect of the conformer state and the model size chosen on the force field of the polypeptide backbone.
abstract: We have attempted to check the validity of our previously calculated ab initio force field for the polypeptide backbone, for the variance with conformer state and model size chosen. For the previous problem we applied our usual ab initio Hartree-Fock SQM method, also used at the original development of the force field, while for the latter we utilized the semiempirical MNDO CO-gradient method. It is shown that the in-plane force field is reasonably stable for change of conformational state, while the out-of-plane force field can be assigned good average guess values. The effect of the model size is shown to be moderate upon introducing a dipeptide into a polymer chain.
authors.affiliation: Department of Atomic Physics, Eötvös L. University, Budapest, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Balázs
authors.forename: P
authors.initials: P
authors.lastname: Rajczy
authors.forename: G
authors.initials: G
authors.lastname: Horváth
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives* / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008962:Models, Theoretical; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D010455:Peptides; C024314:N-acetylalanyl-N-methylamide; D000409:Alanine