AFFINITY PURIFICATION AND CHARACTERIZATION OF A BETA-1,3-GLUCANASE FROM CELERY

beta-1,3-glucanase was purified in a single column step from crude roo t extracts of celery, Apium graveolens L. using a novel affinity chrom atography procedure. The beta-1,3-glucanase was bound to an insoluble anhydroglucose substrate (pachyman) and then eluted by the addition of a soluble substrate (laminarin). The celery enzyme has an isoelectric point of 4.1, an estimated molecular mass of 35 kDa, maximum endo-bet a-l,3-glucanase activity at pH 5.2 and a turnover rate of similar to 2 800 nmol substrate/nmol enzyme/min with laminarin as substrate. The pu rified enzyme partially hydrolyzed isolated cell walls of the celery w ilt pathogen, Fusarium oxysporum Schlect f. sp. apii (R. Nels. and She rb.) Snyd. and Hans.; its activity was substantially increased by the addition of crude root extract containing chitinase. Chitinase activit y on the fungal cell walls was not enhanced by supplementing crude roo t extract with additional purified beta-1,3-glucanase.