Structural guided scaffold phage display libraries as a source of bio-therapeutics.

ABSTRACT: We have developed a structurally-guided scaffold phage display strategy for identification of ligand mimetic bio-therapeutics. As a proof of concept we used the ligand of integrin ?v?6, a tumour cell surface receptor and a major new target for imaging and therapy of many types of solid cancer. NMR structure analysis showed that RGD-helix structures are optimal for ?v?6 ligand-interaction, so we designed novel algorithms to generate human single chain fragment variable (scFv) libraries with synthetic VH-CDR3 encoding RGD-helix hairpins with helices of differing pitch, length and amino acid composition. Study of the lead scFv clones D25scFv and D34scFv and their corresponding VH-CDR3 derived peptides, D25p and D34p, demonstrated: specific binding to recombinant and cellular ?v?6; inhibition of ?v?6-dependent cell and ligand adhesion, ?v?6-dependent cell internalisation; and selective retention by ?v?6-expressing, but not ?v?6-negative, human xenografts. NMR analysis established that both the D25p and D34p retained RGD-helix structures confirming the success of the algorithm. In conclusion, scFv libraries can be engineered based on ligand structural motifs to increase the likelihood of developing powerful bio-therapeutics.

SUBMITTER: Man YK 

PROVIDER: S-EPMC3739823 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature