title: Geometry optimization for peptides and proteins: comparison of Cartesian and internal coordinates.
abstract: We present the results of several benchmarks comparing the relative efficiency of different coordinate systems in optimizing polypeptide geometries. Cartesian, natural internal, and primitive internal coordinates are employed in quasi-Newton minimization for a variety of biomolecules. The peptides and proteins used in these benchmarks range in size from 16 to 999 residues. They vary in complexity from polyalanine helices to a beta-barrel enzyme. We find that the relative performance of the different coordinate systems depends on the parameters of the optimization method, the starting point for the optimization, and the size of the system studied. In general, internal coordinates were found to be advantageous for small peptides. For larger structures, Cartesians appear to be more efficient for empirical potentials where the energy and gradient can be evaluated relatively quickly compared to the cost of the coordinate transformations.
authors.affiliation: University Chemical Laboratories, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Elena F
authors.initials: EF
authors.lastname: Koslover
authors.forename: David J
authors.initials: DJ
authors.lastname: Wales
mesh_terms: D003198:Computer Simulation; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*
chemical_list: D010455:Peptides; D011506:Proteins