PROPERTIES OF A SINGLE-CHAIN ANTIBODY CONTAINING DIFFERENT LINKER PEPTIDES

Single-chain antibodies were constructed using six different linker pe ptides to join the V-H and V-L domains of an anti-2-phenyloxazolone (O x) antibody, Four of the linker peptides originated from the interdoma in linker region of the fungal cellulase CBHI and consisted of 28, 11, six and two amino acid residues, The two other linker peptides used w ere the (GGGGS)(3) linker with 15 amino acid residues and a modified I gG2b hinge peptide with 22 residues, Proteolytic stability and Ox bind ing properties of the six different scFv derivatives produced in Esche richia coli were investigated and compared with those of the correspon ding Fv fragment containing no joining peptide between the V domains, The hapten binding properties of different antibody fragments were stu died by ELISA and BIAcore(TM). The interdomain linker peptide improved the hapten binding properties of the antibody fragment when compared with Fv fragment, but slightly increased its susceptibility to proteas es, Single-chain antibodies with short CBHI linkers of 11, six and two residues had a tendency to form multimers which led to a higher appar ent affinity, The fragments with linkers longer than 11 residues remai ned monomeric.