Figure 1
Construction and selection of human SAI/II specific antibody fragments. A: Antibody formats: scFv, in which the variable regions of the antibody heavy and light chains are combined in the same polypeptide chain joined by a (Gly4Ser)3 amino acid linker. The diabody construct consists of the antibody variable heavy and light chain domains linked by a ten-amino-acid linker (TGGGGSSSAL), forcing the expressed domains to attach to a complementary chain in solution to create two antigen-binding sites. scFv presentation as a protein3 fusion of the M13 phage. B: Chain shuffling approach: The variable antibody domain is cloned into a phagemid vector containing a human antibody variable domain library. The selection on SAI/II antigen was carried out for three consecutive rounds. Light chains participating in binding to SAI/II were identified and cloned into a phagemid vector containing a human antibody heavy domain library. Selection on SAI/II antigen for three rounds yielded fully human SAI/II specific scFv antibody fragments.