GB810566A - Purification of bacillus subtilis protease - Google Patents

Abstract

A process for purifying Bacillus subtilis protease comprises passing a solution of the impure protease buffered at pH 6 to 8 through a coarse, porous cation exchange resin, i.e. one that has pores of such dimensions that proteins of molecular weight from 30,000 to 50,000 may pass through them, which resin is also buffered at pH 6 to 8, eluting the absorbed protease with a solution buffered at a higher pH than that stated above, and collecting separately the colourless and any coloured fractions containing the protease. The cation exchange resins exemplified are phenolic polymers having phenoxyacetic acid exchange groups, e.g. Kaken Resin I, those having methylen sulphonic acid exchange groups, e.g. Dualite C-10, those having hydroxy exchange groups, e.g. Dualite S-30, acrylic polymers having carboxylic acid exchange groups, e.g. Dualite CS-101 and "Amberlite" 1RC-50 ("Amberlite" is a Registered Trade Mark) or styrol polymers having sulphonic acid exchange groups, e.g. Low Crosslinking Dowex -50. In an example a phosphate buffer is used to equilibrate the resin and as carrier for the impure protease, whilst an alkaline buffer comprising sodium chloride, disodium phosphate and ammonia is used as the eluting solution.