Water−Protein Interactions of an Arginine-Rich Membrane Peptide in Lipid Bilayers Investigated by Solid-State Nuclear Magnetic Resonance Spectroscopy

Authors:
Publisher website
Google Scholar
Abstract
The interaction of an arginine (Arg) residue with water in a transmembrane antimicrobial peptide, PG-1, is investigated by two-dimensional heteronuclear correlation (HETCOR), solid-state nuclear magnetic resonance (NMR) spectroscopy. Using 13C and 15N dipolar-edited 1H−15N HETCOR experiments, we unambiguously assigned a water−guanidinium cross-peak that is distinct from intramolecular protein−protein cross-peaks. This water−Arg cross-peak was detected within a short 1H spin diffusion mixing time of 1 ms, indicating that water is in close contact with the membrane-inserted guanidinium. Together with previously observed short guanidinium−phosphate distances, these solid-state NMR data suggest that the Arg side chains of PG-1 are stabilized by both hydration water and neutralizing lipid headgroups. The membrane deformation that occurs when water and lipid headgroups are pulled into the hydrophobic region of the bilayer is symptomatic of the membrane-disruptive function of this antimicrobial peptide. The water−Arg interactions observed here provide direct experimental evidence for molecular dynamics simulations of the solvation of Arg side chains of membrane proteins by deeply embedded water in lipid bilayers.

This publication has 54 references indexed in Scilit: