The twin-arginine translocation (Tat) system is a bacterial protein targeting pathway. Tat-targeted proteins display signal peptides containing a distinctive SRRxFLK 'twin-arginine' motif. The Escherichia coli trimethylamine N-oxide reductase (TorA) bears a bifunctional Tat signal peptide, which directs protein export and serves as a binding site for the TorD biosynthetic chaperone. Here, the p...

Monoclonal antibody (mAb) 5.5 is directed against the ligand-binding site of the nicotinic acetylcholine receptor. The epitope for this antibody is conformation-dependent, and the antibody does not react with synthetic peptides derived from the receptor sequence. We have identified a ligand peptide that mimics this conformation-dependent epitope from a phage-epitope library composed of filament...

Tumor-targeted therapies are playing growing roles in cancer research. The exploitation of these powerful therapeutic modalities largely depends on the discovery of tumor-targeting ligands. Phage display has proven a promising high throughput screening tool for the identification of novel specific peptides with high binding affinity to cancer cells. In the present study, we describe the use of ...

Random peptide libraries (RPL) displayed on the surface of filamentous bacteriophages have been extensively used as a tool to map epitopes or to identify antigenic mimics (mimotpoes) of disease-specific monoclonal antibodies or polyclonal sera. These RPL are engineered by the insertion of degenerate oligonucleotides, encoding a specific number of random amino acids, in frame with a bacteriophag...

Drop-based microfluidics have recently become a novel tool by providing a stable linkage between phenotype and genotype for high throughput screening. However, use of drop-based microfluidics for screening high-affinity peptide binders has not been demonstrated due to the lack of a sensitive functional assay that can detect single DNA molecules in drops. To address this sensitivity issue, we in...

The asp1 integrin binds fibronectin through the integrin recognition sequence Arg-Gly-Asp (RGD). We have used a 6-amino acid peptide library expressed on filamentous phage to identify peptide ligands for asp1. We found that this integrin selectively binds RGD-containing peptides from the library. Of the 32 different sequences obtained, 28 had the RGD motif, 3 contained sequences related to RGD,...

A consensus peptide sequence, QSYP, appears as an artifact during the mapping of monoclonal antibodies (MAbs) using a random peptide phage display library. Phage bearing this QSYP sequence were independently selected by four different laboratories screening separate MAb preparations with the same phage library. In each case, the QSYP sequence was selected in addition to a consensus sequence spe...

In vitro selection targeting an anti-polyhistidine monoclonal antibody was performed using mRNA display with a random, unconstrained 27-mer peptide library. After six rounds of selection, epitope-like peptides were identified that contain two to five consecutive, internal histidines and are biased for arginine residues, without any other identifiable consensus. The epitope was further refined b...

Genetically encoded libraries of peptides and oligonucleotides are well suited for the identification of ligands for many macromolecules. A major drawback of these techniques is that the resultant ligands are subject to degradation by naturally occurring enzymes. Here, a method is described that uses a biologically encoded library for the identification of D-peptide ligands, which should be res...