ISOLATION AND PARTIAL CHARACTERIZATION OF HIGHLY TOXIC LECTINS FROM ABRUS-PULCHELLUS SEEDS

M. V. Ramos, D, M. Mota, C. R. Teixeira, B. S. Cavada and R. A. Moreir a. Isolation and partial characterisation of highly toxic lectins from Abrus pulchellus seeds. Toxicon 36, 477-484, 1998.-The seeds of Abrus pulchellus, sub-specie tenuiflorus, belonging to the Leguminosae, sub family Papilionoideae contain highly toxic lectins exhibiting specific ity for galactose and galactoss-containing structures. The toxins whic h agglutinate rabbit erythrocytes, present a highly toxic activity in vivio when injected in the peritoneal cavity of mice (LD50 = 31 mu g.k g(-1)) or when tested with the microcrustacean Arthemia.salina (LD50=3 .5 mu g.ml(-1)). The active fraction was purified in a single step, by affinity chromotography on a Sepharose-4B column. The purified toxins migrated as two single bands of Mr 63 000 and 61 500 Da (SDS-PAGE) an d Mr 31 500 and 29 000 Da (SDS-PAGE with 2-mercaptoethanol), respectiv ely, suggesting the presence of disulphide-bridge interchains as occur s in other plant toxins. The antibodies anti-A, pulchellus toxins did not recognize ricin preparation and only partial identity was observed to A. precatorius toxic lectins prepared in a similar way to ricin an d A. pulchellus toxins. (C) 1998 Elsevier Science Ltd. All rights rese rved.