The Kinetics and Affinity of Binding of Glu-Plasminogen Specific to the ϵ-Amino Group ofl-Lysine: Its Potential Application to Modified Biomaterials

By covalently couplingl-lysine to an analytical surface through a dipeptide linkage such that the ϵ-amino group is accessible, we have looked at plasminogen binding in real time. The results have led to a model of plasminogen interactions with ϵ-amino groups. This paper focuses on the desorption kinetics of plasminogen adsorbed to this material. Plasminogen is shown to bind to the dipeptide in at least four different ways to the ϵ-amino groups. It is suggested that some molecules bind to several ϵ-amino groups at the same time. The surface plasmon resonance analysis also indicates that the interaction of Glu-plasminogen withl-lysine is very complex and may not be defined simply by discrete kringle interactions alone. Dissociation constants ranging from 0.1 s−1to less than 5 × 10−7s−1are observed. This material may well represent a surface sufficiently similar as to mimic plasminogen binding to fibrin.