Preliminary X-ray studies on Serratia protease.

Preliminary X-ray studies on Serratia protease have been carried out using crystallographic and small angle scattering techniques. The enzyme has been crystallized in three different crystalline forms by microdialysis and vapor diffusion methods using 50 mM phosphate buffer, pH 6.0, at 24 degrees C. They have orthorhombic space groups: C222(1) for one form and P2(1)2(1)2(1) for the other two forms. A small angle X-ray scattering study showed that the radius of gyration and the maximal dimension of the molecule in aqueous solution are 26.6 A and 94.5 A, respectively. The molecular weight of the enzyme was determined to be 45,000-48,000 by various physical methods.