Journal Article Proteins Research Support, Non-U.S. Gov't impurity depletion zone microgravity protein crystal protein depletion zone Cellulase EC 3.2.1.- EC 3.2.1.17 EC 3.2.1.4 Glycoside Hydrolases H-protein JAXA Japan Experiment Module `Kibo' Muramidase cellulase counter-diffusion crystallization phase diagram high-pressure cryocooling method high-resolution X-ray crystallography neutron protein crystallography numerical model transient and diffusive field transient and homogeneous field