PURIFICATION OF ENDO-POLYGALACTURONASE BY AFFINITY PRECIPITATION USING ALGINATE

The precipitation of alginate by Ca2+ at pH 3.8 was found to occur con comitantly with the precipitation of endo-polygalacturonase from Asper gillus niger. Under optimum conditions, 92% of the enzyme activity was precipitated. The enzyme could be recovered from the precipitate by w ashing with 0.5 M NaCl/0.2 M Ca2+. All the precipitated endo-polygalac turonase activity could be recovered in this way. The enzyme thus obta ined was purified 10-fold. A comparison of SDS/PAGE gel patterns of th e crude preparation and enzyme purified by the affinity precipitation also showed a significant purification of the enzyme.