CRYSTALLIZATION OF PUMPKIN SEED GLOBULIN - GROWTH AND DISSOLUTION KINETICS

Quasi-elastic light scattering was used to investigate the nucleation and crystallization of pumpkin (Cucurbita) seed globulin. The diameter of the pumpkin globulin monomer was measured to be almost-equal-to 5- 6 nm. The supersaturation dependence of critical nucleus size was obta ined, and this allowed an estimate of the interfacial free energy to b e alpha almost-equal-to 6.1 x 10(-2) erg/cm2. The crystallization and dissolution kinetics were investigated for 4.9-16 mg/ml protein soluti ons containing 1-7% NaCl. The solubility data as a function of precipi tant concentration and temperature were obtained and these will be uti lized for optimization of the crystallization conditions for the pumpk in globulin.