Provided is a multivalent single-chain binding protein comprising from amino to carboxy terminus: a. a first binding domain derived from an immunoglobulin-like molecule or the variable regions of an immunoglobulin b. a constant sub-region comprising an immunoglobulin CH2 domain and a CH3 domain c. a scorpion linker, wherein said scorpion linker comprises an amino acid sequence derived from a hinge of an immunoglobulin or immunoglobulin-like molecule or an extracellular stalk region of a type 2 membrane protein in the C-type lectin family and d. a second binding domain derived from an immunoglobulin-like molecule or the variable regions of an immunoglobulin.
