RESUMO
The epidermal growth factor receptor (EGFR) dimerization arm is a key feature that stabilizes dimerization of the extracellular receptor, thereby mediating activation of the tyrosine kinase domain. Peptides mimicking this ß-loop feature can disrupt dimer formation and kinase activation, yet these peptides lack structural constraints or contain redox sensitive disulfide bonds which may limit their stability in physiological environments. Selenylsulfide bonds are a promising alternative to disulfide bonds as they maintain much of the same structural and chemical behavior, yet they are inherently less prone to reduction. Herein, we describe the synthesis, stability and activity of selenylsulfide-bridged dimerization arm mimics. The synthesis was accomplished using an Fmoc-based strategy along with C-terminal labeling for improved overall yield. This selenylsulfide-bridged peptide displayed both proteolytic stability and structural stability even under reducing conditions, demonstrating the potential application of the selenylsulfide bond to generate redox stable ß-loop peptides for disruption of protein-protein interactions.
Assuntos
Receptores ErbB/metabolismo , Peptídeos/química , Peptidomiméticos/química , Multimerização Proteica/efeitos dos fármacos , Selênio/química , Sulfetos/química , Sequência de Aminoácidos , Animais , Linhagem Celular , Desenho de Fármacos , Receptores ErbB/química , Humanos , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Peptídeos/síntese química , Peptídeos/farmacologia , Peptidomiméticos/síntese química , Peptidomiméticos/farmacologia , Conformação Proteica/efeitos dos fármacos , Mapas de Interação de Proteínas/efeitos dos fármacos , Estabilidade Proteica , Selênio/farmacologia , Sulfetos/síntese química , Sulfetos/farmacologiaRESUMO
The epidermal growth factor receptor (EGFR) is overexpressed in multiple carcinomas and is the focus of a variety of targeted therapies. Here we report the design of peptide-based compounds that mimic the EGFR dimerization arm and inhibit allosteric activation of EGFR. These peptides are modified to contain a triazolyl bridge between the peptide strands to constrain the EGFR dimerization arm ß-loop. In this study, we demonstrate that these peptides have significantly improved proteolytic stability over the non-modified peptide sequence, and their inhibitory effects are dependent on the number of the methylene units and orientation of the introduced triazolyl bridge. We identified a peptide, EDA2, which downregulates receptor phosphorylation and dimerization and reduces cell viability. This is the first example of a biologically active triazolyl-bridged peptide targeting the EGFR dimerization interface that effectively downregulates EGFR activation.