Purification of amylases and other enzymes by a forced-affinity chromatography method.

An affinity matrix of soluble starch gel was prepared by cross-linking catalyzed by epichlorohydrin. The elution pattern of Taka-amylase A (TAA) indicated that the amount of enzyme bound to the starch gel column increased with increases in the ammonium sulfate (AmS) concentration in the equilibrating buffer. TAA had an affinity for the gels with a starch structure, and desorbed from the column with the buffer containing no AmS. Bound TAA was also eluted with starch and cyclodextrin solution. The AmS stimulative effect was partially replaced by polyethylene glycol and surfactants. Besides TAA, various, other amylases bound satisfactorily to the starch gel. Moreover, affinity purifications of dextranase, cellulase, and pectinase were done by gels with dextran, cellulose, and pectin structures, respectively. By the aid of forced effects of AmS, various carbohydrases could be purified by the affinity gels of polysaccharide linked by epichlorohydrin.