Cyclic, Cell-Penetrating Peptides Tailor-Made for the Creation of Peptide Libraries with Intrinsic Cell Permeability

The discovery of high-affinity peptides to many intracellular targets has become feasible through the development of diverse macrocyclic peptide libraries. But lack of cell permeability is a key feature hampering the use of these peptides as therapeutics. Here, we develop a set of small, cyclic peptide carriers that efficiently carry cargoes into the cytosol. These peptides are cyclized via side-chain alkylation, which makes them ideal for the creation of diverse mRNA or phage-displayed libraries with intrinsic cell permeability.</p

Continuous Fluorescence Assay for In Vitro Translation Compatible with Noncanonical Amino Acids

The tolerance of the translation apparatus toward noncanonical amino acids (ncAAs) has enabled the creation of diverse natural-product-like peptide libraries using mRNA display for use in drug discovery. Typical experiments testing for ribosomal ncAA incorporation involve radioactive end point assays to measure yield alongside mass spectrometry experiments to validate incorporation. These end point assays require significant postexperimental manipulation for analysis and prevent higher throughput analysis and optimization experiments. Continuous assays for in vitro translation involve the synthesis of fluorescent proteins which require the full complement of canonical AAs for function and are therefore of limited utility for testing of ncAAs. Here, we describe a new, continuous fluorescence assay for in vitro translation based on detection of a short peptide tag using an affinity clamp protein, which exhibits changes in its fluorescent properties upon binding. Using this assay in a 384-well format, we were able to validate the incorporation of a variety of ncAAs and also quickly test for the codon reading specificities of a variety of Escherichia coli tRNAs. This assay enables rapid assessment of ncAAs and optimization of translation components and is therefore expected to advance the engineering of the translation apparatus for drug discovery and synthetic biology

A New Strategy for the \u3ci\u3eIn Vitro\u3c/i\u3e Selection of Stapled Peptide Inhibitors by mRNA Display

Hydrocarbon stapled peptides are promising therapeutics for inhibition of intracellular protein–protein interactions. Here we develop a new high-throughput strategy for hydrocarbon stapled peptide discovery based on mRNA display of peptides containing α-methyl cysteine and cyclized with m-dibromoxylene. We focus on development of a peptide binder to the HPV16 E2 protein

Esophageal epithelial cells produce cytokines in response to histamine stimulation <i>in vitro</i>.

<p>Quantification of GM-CSF, TNFα, and IL-8 (pg/mL) secretion by histamine stimulated EPC2-hTERT cells (100uM histamine for 24 hrs). Two-tailed student t-test was used for statistical analysis. **p<0.005,***<0.0005. Effect of pretreatment with H1R antagonist pyrilamine or H2R antagonists (cimetidine and ranitidine) prior to histamine stimulation upon cytokine secretion in EPC2-hTERT cells (<b><i>B-D</i></b>). One way ANOVA with Bonferroni post-test was used for statistical analysis. *p<0.05, **p<.01,****p<0.0001. ns = not significant. Data are represented as the mean +/- SEM of n = 6.</p

Expression of H1R, H2R, and H4R 4 are increased in esophageal biopsies in actively inflamed EoE.

<p>Comparison of H1,H2, H3, and H4 receptor expression in non-EoE control, inactive EoE and active EoE biopsies, using Mann-Whitney test (<b>A-D</b>). Horizontal bars represent median of each data set. Horizontal lines represent median of the data set.</p