Optical diffractometer for facilitation of x-ray diffraction studies of macromolecular structures.

Abstract

An instrument employing optical analogies to the diffraction of x-rays by macromolecular substances is described. Simple and readily obtainable components, materials and procedures are involved. Photographic methods are used to reduce the size of models for trial structures in forming masks whose optical diffraction is then compared with the x-ray diffraction of real structures. Conversely, the diffractometer can be employed to synthesize images of structures from masks simulating observed x-ray diffraction.Applications are described dealing with the investigation of helical chain molecules (polypeptide α helices, collagen and deoxyribonucleate molecules); with the study of larger sized structures exhibiting small-angle x-ray diffraction (e.g., collagen fibrils); and with image synthesis for centrosymmetric configurations (phthalocyanine).