An algorithm for converting a virtual-bond chain into a complete polypeptide backbone chain

Abstract
A systematic analysis is presented of the algorithm for convering a virtual-bond chain, defined by the coordinates of theα-carbons of a given protein, into a complete polypeptide backbone. An alternative algorithm, based upon the same set of geometric parameters used in the Purisima-Scheraga algorithm [1] but with a different “linkage map” of the algorithmic procedures, is proposed. The global virtual-bond chain geometric constraints are more easily separable from the loal peptide geometric and energetic constraints derived from, for example. the Ramachandran criterion [2, 3], within the framework of this approach.