Process for the preparation of codehydrogenase i (diphosphopyridine nucleotide) of high purity from yeast

摘要

Codehydrogenase I of high purity is prepared by passing an aqueous solution containing codehydrogenase obtained from extraction of yeast through a highly porous weakly basic anion exchange resin in the salt form to give a colourless codehydrogenase-I effluent solution, making the effluent solution acidic to pH 2-3, passing the resulting solution through a highly porous strongly acidic cation exchange resin of the sulphonic acid type in the hydrogen form, washing the resin layer with an aqueous buffer solution of pH 2-3 and eluting the adsorbed codehydrogenase I with an aqueous buffer solution of pH 4-7 and recovering codehydrogenase I from the eluate. Specified anion exchange resins are "Duolite A-2" (Registered Trade Mark) and "Duolite A-7" in salt form such as the acetate, formate, chloride or phosphate. The effluent thereof is adjusted to pH 2-3 with hydrochloric, sulphuric, nitric or phosphoric acid or an organic acid such as formic or acetic acid. Specified cation exchange resins are Duolite C-10 and Duolite C-25. The cation exchange resin is washed with ammonium chloride aqueous buffer and eluted with an acetate or citrate buffer. The codehydrogenase-I is recovered from the eluate by acidification and precipitation with an organic solvent, e.g. ethanol or acetone.