Purification of endo‐polygalacturonase by affinity precipitation using alginate

Abstract

The precipitation of alginate by Ca2+ at pH 3.8 was found to occur concomitantly with the precipitation of endo‐polygalacturonase from Aspergillus niger. Under optimum conditions, 92% of the enzyme activity was precipitated. The enzyme could be recovered from the precipitate by washing with 0.5 M NaCl/0.2 M Ca2+. All the precipitated endo‐polygalacturonase activity could be recovered in this way. The enzyme thus obtained was purified 10‐fold. A comparison of SDS/PAGE gel patterns of the crude preparation and enzyme purified by the affinity precipitation also showed a significant purification of the enzyme.