MONOCLONAL-ANTIBODIES AGAINST A MINOR AND THE MAJOR COAT PROTEINS OF FILAMENTOUS PHAGE M13 - THEIR APPLICATION IN PHAGE DISPLAY

We have produced monoclonal antibodies (MAbs) which react with a minor and the major coat proteins of filamentous phage M13 and have charact erised them by combining the techniques of enzyme-linked immunosorbent assay (ELISA) and Western blotting. These coat proteins are the minor coat protein, gIIIp, the product of gene III and the major coat prote in, gVIIIp, the product of gene VIII. Both gIIIp and gVIIIp are import ant in the context of 'phage display' of foreign peptides/proteins as fusions to these proteins. The anti-gIIIp MAbs were able to detect nat ive gIIIp as well as the fusion proteins comprising foreign proteins a nd gIIIp in ELISA and on Western blot, indicating their utility for st udying the expression of foreign proteins in phage display. Similarly anti-gVIIIp MAbs detected gVIIIp both in ELISA and on Western blot. In an 'affinity capture phage ELISA', phages that were captured by virtu e of the interaction between the foreign protein (ligand fused to the gIIIp and displayed on the phage surface) and the immobilised counterp art (receptor), could be easily detected using anti-gVIIIp MAbs. Consi dering the potential of 'phage display' technology in protein engineer ing, these antibodies should find wide applications.