PURIFICATION AND CHARACTERIZATION OF A LECTIN FROM SEEDS AND COTYLEDONARY CALLUS OF ZIZYPHUS-MAURITIANA

A lectin from Zizyphus mauritiana lamk. has been purified from the 25- 50% (NH4)(2)SO4 fraction of crude seed and cotyledonary leaf callus ex tracts. The lectins purified from the two sources had the same structu re and properties. Upon specific adsorption on Sephadex G-100, the lec tin (ZML) could be displaced with 0.1 M D-glucose. ZML yielded a singl e band corresponding to a M-r of 66 kDa both in the absence and presen ce of beta-mercaptoethanol on native-as well as in SDS-PAGE. It is the rmostable but pH sensitive and agglutinates human erythrocytes only. L ectin activity could also be detected in the cotyledons, leaf, and ste m, and in their cultures, as well as in in vitro regenerants. Cotyledo ns, cotyledonary leaf and its callus showed much higher lectin activit y than seeds.