RESUMEN
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.
RESUMEN
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.
Asunto(s)
Azidas/química , Proteasa del VIH/química , Secuencia de Aminoácidos , Azidas/síntesis química , Datos de Secuencia Molecular , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
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.
Asunto(s)
Quimiocina CCL5/síntesis química , Procesos Fotoquímicos , Linfocitos T/fisiología , Animales , Células Cultivadas , Quimiotaxis , Humanos , RatonesRESUMEN
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.
Asunto(s)
Quimiocina CCL11/síntesis química , Oligopéptidos/síntesis química , Compuestos de Azufre/síntesis química , Secuencia de Aminoácidos , Quimiocina CCL11/química , Humanos , Estructura Molecular , Oligopéptidos/química , Técnicas de Síntesis en Fase Sólida , Compuestos de Azufre/química , Ácido Trifluoroacético/químicaAsunto(s)
Aminoácidos Diaminos/química , Disulfuros/síntesis química , Péptidos/síntesis química , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Bacterias/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Dicroismo Circular , Ciclización , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/farmacología , Disulfuros/química , Disulfuros/farmacología , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Péptidos/química , Péptidos/farmacología , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Técnicas de Síntesis en Fase SólidaRESUMEN
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.
Asunto(s)
Hidrazinas/química , Oligopéptidos/química , Péptidos Cíclicos/síntesis química , Proteínas/síntesis química , Ciclización , Estructura Molecular , Péptidos Cíclicos/química , Proteínas/químicaRESUMEN
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.