IMPORTANCE OF THE LINKER IN EXPRESSION OF SINGLE-CHAIN FV ANTIBODY FRAGMENTS - OPTIMIZATION OF PEPTIDE SEQUENCE USING PHAGE DISPLAY TECHNOLOGY

We have investigated the potential for enhancing the production of fun ctional single-chain Fv antibody fragments (sFv), by altering the sequ ence of the linker that joins the variable domains of the molecule. To identify new functionally improved linkers we have used a phage displ ay library containing a random sequence of six amino acids in the link er. Multiple rounds of panning on the antigen led to the selection of six different linker sequences that enhanced the binding of phage to t he antigen. Five of the linkers also improved the secretion of soluble sFv by approximately five-fold. Analysis of the predominant linker se quence isolated showed that this improvement is not due to an increase d affinity for the antigen, nor to alterations in the toxicity to bact eria. However the linker did affect the denaturation of the sFv in ure a. It is therefore possible that the novel sequence helps in the refol ding or secretion of the molecule. (C) 1997 Elsevier Science B.V.