Disulfide-Stabilized Fv Fragments

The design and generation of disulfide-stabilized Fv fragments (dsFv’s) addresses stability and aggregation problems that are frequently associated with single-chain Fvs. V_H and V_L of dsFv’s are connected by an interdomain disulfide bond. To generate such molecules, one amino acid each in the framework region of in V_H (at position 44) and V_L (at position 100) are mutated to a cysteine, which in turn form a stable interchain disulfide bond. The resulting dsFv’s (no linker peptide) or scdsFv (linker as well as interchain disulfide bond) can be easily produced in various expression systems. Disulfide-stabilized Fv’s solve most problems that are frequently associated with Fvs or scFvs; they are very stable and in most instances show full antigen binding activity.