The Effects Of Linker On Dimerization Of Anti-Fibrin ScFv

Single-chain Fv (ScFv) is recombinant antibody fragment consisting of only the variable light chain (V_L) and variable heavy chain (V_H) domains covalently connected to one another by a polypeptide linker. Due to the small size, the scFv shows faster plasma clearance and stronger tissue penetration in vivo, and easier being linked to another effector molecules at the C-terminal. It has binding specificity as its parent antibody does, but has no non -specific binding induced by the Fc fragments. These advantages favour the scFv applications as imaging reagents for tumor localization and targeting delivery of drugs, toxins or radionuclides to the tumor. ScFv-8E5 is a 30KDa single chain Fv with the antigen-binding specificity against a synthetic heptapeptide of the β chain of human fibrin. Therefore, it may be useful in thrombosis imagine and targeting thrombolytic therapy. Investigation data shows that bivalent scFv has better antigen-binding specificity and stability than those of the monomer. It can also be formed by two heterogenic scFvs as bifunctional biabody.In this studies, the linker of the scFv-8E5 has been modified. The effects of the modifications on (scFv)₂ dimer formation and antigen binding have been carried out.Methods : The DNA fragments of three linkers were synthesized as parts of the primers. Using PCR techniquence, each linker was inserted between the V_H and V_L to replace the primary linker in pOPE51-8E5. Three...