The bifunctional SLK consisting of the scFv-A11, that binds to an epitope on activated α_IIbβ₃ (GPIIb-IIIa) and induces platelet lysis, fused to the kringle 1 domain that recognizes fibrin (not fibrinogen). This construct can target an active thrombus (via activated α_IIbβ₃/polymerized fibrin) providing both dual antithrombotic activity and a unique therapeutic approach. Monovalent antibody also induces oxidative lysis via α_IIbβ₃, while kringle-containing plasminogen interacts directly with fibrin.