Involvement of the lysine-binding sites of plasminogen on its interaction with concanavalin A

Two different interactions are involved in the binding of plasminogen to concanavalin A-Sepharose: both variants 1 and 2 interact with the lectin through the lysine-binding sites and, in addition, variant 1 binds to concanavalin A due to carbohydrate recognition. Both kinds of interactions were also observed in solution by analytical ultracentrifugation. The binding of Lys-plasminogen to concanavalin A via lysine-binding sites largely exceeds that of Glu-plasminogen, in accordance with the higher affinity for lysine of Lys-plasminogen. This fact can be applied to the separation of both forms of plasminogen in a single chromatographic step.