Solid-State NMR Investigations of Membrane-Associated Antimicrobial Peptides
Solid-state NMR and other biophysical investigations have revealed many mechanistic details about the interactions of antimicrobial peptides with membranes. These studies have shaped our view on how these peptides cause the killing of bacteria, fungi, or tumour cells and how they permeabilize model membranes. As a result, we better understand the biological activities of these peptides and we are now able to design new and better sequences. Here we present some of the tools that have allowed these solid-state NMR investigations, including detailed protocols on how to reconstitute the peptides into oriented or non-oriented membranes as well as simple set-up procedures for 2H as well as proton-decoupled 31P or 15N solid-state NMR measurements. Static and magic angle spinning experiments are described. Where adequate, the special requirements for or limitations of some of the measurements are discussed. Solid-state NMR spectra of both lipids and peptides have been recorded, and through the ensemble of measurements a detailed picture of these complex peptide–lipid supramolecular systems has finally emerged.
Key wordsMembrane reconstitution oriented bilayer helix topology amphipathic peptide surface alignment transmembrane orientation membrane protein structure peptide–lipid interactions pore formation channel magic angle spinning
We are thankful to Vaincre la Mucoviscidose (TG0101), the Association pour la Recherche sur le Cancer (No. 3100), the Agence Nationale pour la Recherche, the RMN Grand-Est Network of the Ministry of Recherche, the International Center for Frontier Research in Chemistry, and the European Union (MCRTN 33439-Biocontrol) for supporting our projects. The Institute for Supramolecular Chemistry of the University of Strasbourg (ISIS) is acknowledged for hosting the laboratory.
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