This research will establish precisely defined protein structural systems through the application of X-ray crystallographic techniques for the purpose of providing a sound physical basis for biochemical experimentation. The analysis of several proteins to high resolution will be undertaken which initially will include creatine kinase, abrin, catalase, ferritin, canavalin, concanavalin B, and alpha-amylase. Isolation, crystallization, some biochemical characterization and preliminary X-ray diffraction investigations have already been conducted on each of these. Emphasis will be placed on those proteins of most relevant biological interest (creatine kinase, abrin, alpha-amylase, catalase and ferritin) with the objective of elucidating their mechanistic features by examining their structures in the presence of their respective substrates, coenzymes, transition state analogues and effectors by employing the difference Fourier technique. In addition, the studies will examine unique structural features such as a glycoprotein, a virus model, and several unique quaternary structures. A method will be developed for extracting low resolution phase information from electron micrographs for the purpose of expediting X-ray structural analyses. In addition, a system will be set up for digital and optical filtering of electron micrographs.