NEW LECTINS FROM BULBS OF CROCUS-SATIVUS

Four isolectins were isolated from bulbs of Croccus sativum (saffron), using affinity chromatography on mannan-Sepharose 4B, gel filtration and ion-exchange column chromatography in the presence of 8 M urea. Th e relative molecular masses of these lectins were determined by gel fi ltration to be approximately 48 kDa. On polyacrylamide gel electrophor esis, relative molecular masses of 8 kDa were obtained, suggesting tha t the lectins are hexamers. No carbohydrates were detected in the lect ins. The lectins agglutinated the yeasts of Saccharomyces cerevisiae a t a minimum concentration of 30 mug/ml, however, they did not agglutin ate animal erythrocytes (human, sheep, rabbit and mouse) even at a con centration of 1000 mug/ml. In inhibitory experiments, mannan from Sacc haromyces cerevisiae was the most potent inhibitor of C. sativum lecti ns. While D-mannose showed no inhibition, manno-oligosaccharides with either (alpha 1-2, 1-3) or (alpha 1-6) linkages were potent inhibitors , suggesting that C. sativum lectins recognized manno-oligosaccharide units larger than mannobiose. Ovomucoid also exhibited potent inhibiti on, however, the other carbohydrates examined did not.