RESUMO
Blockade of the protein-protein interaction between the transmembrane protein programmed cell death protein 1 (PD-1) and its ligand PD-L1 has emerged as a promising immunotherapy for treating cancers. Using the technology of mirror-image phage display, we developed the first hydrolysis-resistant D-peptide antagonists to target the PD-1/PD-L1 pathway. The optimized compound (D) PPA-1 could bind PD-L1 at an affinity of 0.51 µM in vitro. A blockade assay at the cellular level and tumor-bearing mice experiments indicated that (D) PPA-1 could also effectively disrupt the PD-1/PD-L1 interaction in vivo. Thus D-peptide antagonists may provide novel low-molecular-weight drug candidates for cancer immunotherapy.
RESUMO
The first total chemical synthesis of the site-selective azide-labeled [I66A]HIV-1 protease is described by native chemical ligation. Chemical synthesis of azide-labeled proteins would provide useful protein tools for biochemical, biophysical or medical studies.
Assuntos
Azidas/química , Protease de HIV/química , Sequência de Aminoácidos , Azidas/síntese química , Dados de Sequência Molecular , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Chemokine-guided lymphocyte positioning in tissues is crucial for normal operation of the immune system. Direct, real-time manipulation and measurement of single-cell responses to chemokines is highly desired for investigating the cell biology of lymphocyte migration in vivo. Here we report the development of the first two-photon-activatable chemokine CCL5 through efficient one-pot total chemical synthesis in milligram scale. By spatiotemporally controlled photoactivation, we show at the single-cell level that T cells perceive the directional cue without relying on PI3K activities, which are nonetheless required for persistent migration over an extended period of time. By intravital imaging, we demonstrate artificial T-cell positioning in cutaneous tissues and lymph nodes. This work establishes a general strategy to develop high-quality photo-activatable protein agents through tailor-designed caging of multiple residues and highlights the potential of photo-activatable chemokines for understanding and potential therapeutic manipulation of cell positioning and position-controlled cell behaviours in vivo.
Assuntos
Quimiocina CCL5/síntese química , Processos Fotoquímicos , Linfócitos T/fisiologia , Animais , Células Cultivadas , Quimiotaxia , Humanos , CamundongosRESUMO
A new synthetic method for peptide thioesters is described using Fmoc solid-phase peptide synthesis (Fmoc-SPPS). This method employs a novel enamide motif to facilitate irreversible intramolecular N-to-S acyl migration, which can efficiently afford the desired peptide thioesters (3 h, 30 °C) under the final trifluoroacetic acid (TFA) cleavage conditions. The acyl-transfer-mediated approach for synthesis of peptide thioesters tolerated different C-terminal residues and was used to synthesize human C-C motif chemokine 11 (hCCL11) via native chemical ligation.
Assuntos
Quimiocina CCL11/síntese química , Oligopeptídeos/síntese química , Compostos de Enxofre/síntese química , Sequência de Aminoácidos , Quimiocina CCL11/química , Humanos , Estrutura Molecular , Oligopeptídeos/química , Técnicas de Síntese em Fase Sólida , Compostos de Enxofre/química , Ácido Trifluoracético/químicaAssuntos
Diamino Aminoácidos/química , Dissulfetos/síntese química , Peptídeos/síntese química , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Ciclização , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/farmacologia , Dissulfetos/química , Dissulfetos/farmacologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Peptídeos/química , Peptídeos/farmacologia , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia , Técnicas de Síntese em Fase SólidaRESUMO
Intramolecular ligation of peptide hydrazides is reported to occur readily, causing the lactamization of fully unprotected peptides in an epimerization-free manner. This method relies on the routine procedures of Fmoc solid-phase peptide synthesis. It can be used to prepare cyclic peptides and cyclic proteins under simpler, mild conditions at lower costs.
Assuntos
Hidrazinas/química , Oligopeptídeos/química , Peptídeos Cíclicos/síntese química , Proteínas/síntese química , Ciclização , Estrutura Molecular , Peptídeos Cíclicos/química , Proteínas/químicaRESUMO
An operationally simple method for the synthesis of peptide thioesters is developed using standard Fmoc solid-phase peptide synthesis procedures. The method relies on the use of a premade enamide-containing amino acid which, in the final TFA cleavage step, renders the desired thioester functionality through an irreversible intramolecular N-to-S acyl transfer.