Display phage

Affinity and specificity of proteinase inhibitors can be optimized by phage display... 

How do the mutations identified by phage display improve binding specificity There is as yet no direct stmctural information on the phage-selected inhibitors however they can be modeled using data from the crystal structures of other Kunitz domains bound to serine proteinases. These studies lead to the conclusion that the mutations identified by phage display improve binding specificity by maximizing complementarity between the... 

Figure 17.10 Construction of a two helix truncated Z domain, (a) Diagram of the three-helix bundle Z domain of protein A (blue) bound to the Fc fragment of IgG (green). The third helix stabilizes the two Fc-binding helices, (b) Three phage-display libraries of the truncated Z-domaln peptide were selected for binding to the Fc. First, four residues at the former helix 3 interface ("exoface") were sorted the consensus sequence from this library was used as the template for an "intrafece" library, in which residues between helices 1 and 2 were randomized. The most active sequence from this library was used as a template for five libraries in which residues on the Fc-binding face ("interface") were randomized. Colored residues were randomized blue residues were conserved as the wild-type amino acid while yellow residues reached a nonwild-type consensus, [(b) Adapted from A.C. Braisted and J.A. Wells,...

Phage display of random peptide libraries identified agonists of erythropoietin receptor... 

EMPl, selected by phage display from random peptide libraries, demonstrates that a dimer of a 20-residue peptide can mimic the function of a monomeric 166-residue protein. In contrast to the minimized Z domain, this selected peptide shares neither the sequence nor the structure of the natural hormone. Thus, there can be a number of ways to solve a molecular recognition problem, and combinatorial methods such as phage display allow us to sort through a multitude of structural scaffolds to discover novel solutions. 

Protein engineering is now routinely used to modify protein molecules either via site-directed mutagenesis or by combinatorial methods. Factors that are Important for the stability of proteins have been studied, such as stabilization of a helices and reducing the number of conformations in the unfolded state. Combinatorial methods produce a large number of random mutants from which those with the desired properties are selected in vitro using phage display. Specific enzyme inhibitors, increased enzymatic activity and agonists of receptor molecules are examples of successful use of this method. 

Kay, B.K, Winter, J., McCafferty, J. eds. Phage Display of Peptides and Proteins a Laboratory Manual. San Diego Academic Press, 1996. 

Dennis, M.S., Herzka, A., Lazarus, R.A. Potent and selective Kunitz domain inhibitors of plasma kallikrein designed by phage display. /. Biol. Chem. 270 25411-25417, 1995. 

Structural scaffolds can be reduced in size while function is retained Phage display of random peptide librciries... 

Isotope labeling Phage display Protein arrays Computational approaches... 

Use of phage display to detect protein-ligand interactions... 

The advantage of the Jun-Fos phage display system is that the fusion of the library DNA is to the C-terminus of a protein rather than between the... 

---