Purification of extracellular proteinases from B. subtilis SKB 256 by biospecific chromatography

A simple and efficient method of preparing highly purified extracellular proteinases of B. subtilis B-1 (SKB 256) has been developed. A sorbent based on sorsilen impregnated with hemoglobin or cytochrome c has been synthesized for this purpose. A significant difference between the efficiency of hemoglobin and cytochrome c as biospecific ligands has been observed: the enzyme yield amounted to 40.6 and 65.6% of the total amount of enzyme adsorbed, respectively. The culture was shown to contain two major proteinase forms with different molecular masses that could be separated by chromatography on a Sephadex G-50 but gave only one band with MW 27 kDa upon denaturing electrophoresis in 12.5% PAG in the presence of 0.1% SDS. The influence of eluent pH, ionic strength and ethanol concentration on the sorption of the proteinases on the biospecific sorbent, as well as on the desorption from it, has been investigated. Positive influence of 20% ethanol on proteinase desorption has been demonstrated.