Engineering M13 bacteriophage for high-valency carboxy-terminal display of peptides
Heike A. Held* and Sachdev S. Sidhu.
Department of Protein Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, CA
94080.
Display of peptide libraries on M13 phage has been widely used to identify protein ligands. Due
to the orientation of the M13 coat proteins, this method had long believed not be amenable to
interactions involving a free carboxy-terminus of the ligand, however. Recently, Fuh et al.1
demonstrated that the major coat protein indeed supports carboxy-terminal peptide display.
While their system generated ligands of two PDZ domains, its applicability is limited to rather
tight interactions. In order to expand the scope of C-terminal interactions accessible to
investigation by peptide phage display, we developed a higher-valency display format. M13
phage libraries containing 1010 different major coat protein mutants were subjected to 8 rounds
of selection for C-terminal display of a decamer. A phage mutant was obtained that displayed the
peptide with 80-fold higher efficiency than the wild type phage. The amino acids responsible for
tolerance of the carboxy-terminal fusion form two epitopes at either end of the major coat
protein.
References:
1. G. Fuh, M.T. Pisabarro, Y. Li, C. Quan, L.A. Lasky, and S.S.Sidhu (2000) Analysis of PDZ
domain-ligand interactions using carboxyl-terminal phage display. J. Biol. Chem. 275, 21486-
21491.