Legume alpha-Galactosidases Which Have Hemagglutinin Properties

Four legume species (four genera) were examined and found to contain hemagglutinins with properties similar to those which we have previously described for the enzymic hemagglutinin in Vigna radiata. Examination of extracts by gel filtration and ion exchange chromatography showed that an alpha-galactosidase activity exactly co-purified with a hemagglutinin activity in each of the four species. The alpha-galactosidase activities in the four species were virtually identical to each other with respect to substrate and inhibitor specificity as well as kinetic behavior. Additionally the hemagglutinin activities in all four species displayed very similar carbohydrate specificities. The inhibitor specificities displayed by the enzymes and the hemagglutinins were qualitatively and quantitatively very nearly identical to each other. The remarkable similarities of these proteins, both to each other and to the previously described Vigna enzymic hemagglutinin, suggest that each of these plants may contain a homologue from a specific class of enzymic hemagglutinin.