Subunit Composition and Molecular Weights of the Developmentally Regulated Lectins from Dictyostelium Discoideum

Discoidin I, the developmentally regulated carbohydrate binding protein from Dictyostelium discoideum, migrated as a broad band during electrophoretic analysis using 10% polyacrylamide gels in the presence of sodium dodecyl sulfate. The band could be resolved into two components by electrophoresis on 15% polyacrylamide gels. All highly purified preparations of discoidin I contained equal amounts of the two components, suggesting they are nonidentical subunits of the protein. The subunit molecular weights of discoidin I and discoidin II were found to be 29,500 and 26,500, values somewhat larger than those previously reported.