Sidechain and backbone potential function for conformational analysis of proteins.

An improved potential function has been devised for the calculation of protein conformations. Each amino acid residue is represented by two points. The mainchain is traced by the sequence of C alpha atoms, and the details of sidechain structure and interactions are represented by a representative sidechain atom. This potential function has been developed from a data base of 22 high resolution protein crystal structures and includes the components of an earlier potential developed from a similar data base where each amino acid residue is represented by only its C alpha atom. In virtually all aspects of testing, the present potential betters the previous single-point potential, and is shown to be useful in the simulation of protein folding.