A quantitatively major protein has been purified from the latex of Morus indica. The purified previously uncharacterized protein, M. indica lectin (MIL), was further shown to be a glycosylated tetramer and belongs to the family of jacalin-related lectins. Crystallization of MIL was also accomplished and the tetragonal crystals diffracted synchrotron X-rays to a resolution of 2.8 Å.