Some new methods and general results of analysis of protein crystallographic structural data

Abstract

Some methods of analysis and representation of folding of chain using the structural data from X-ray analysis of protein crystals are discussed. Considering a set of four consecutive C^a-atoms to be the smallest segment for purposes of helical analysis, parameters are defined to characterize the helical axes and also dihedral angle involving the virtual bonds. These are used to devise one and two-dimensional representations which yield meaningful information regarding chain folding. Results of application to actual protein data are discussed. A method of using stereographic projection involving helical axes is discussed with illustrations.