[Affinity chromatography of proteases using peptide methyl ketones as ligands]

Peptide methyl ketones acting as reversible inhibitors of serine and cysteine proteases were introduced as a new type of ligands in the affinity chromatography. Subtilisins and related serine proteases with an inhibition constant to the soluble inhibitor Z-Ala2-PheCH3 of less or equal than 3 x 10(-5) M are nearly completely adsorbed by the affinity gel Sepharose 4B-epsilon-aminocaproic acid-Ala2-PheCH3. The well-known cysteine protease papain binds also to this gel. The elution of the enzymes could be performed by means of iso-propanol. Thermitase purified with this method is, regarding to its quality, comparable with enzyme preparations using isoelectric focusing and adsorption at porous glass bodies, respectively.