Effects of Guanidinium–Phosphate Hydrogen Bonding on the Membrane‐Bound Structure and Activity of an Arginine‐Rich Membrane Peptide from Solid‐State NMR Spectroscopy

Barreling through: Guanidinium–phosphate hydrogen bonding significantly affects the structure and activity of the antimicrobial peptide PG-1. Solid-state NMR data show that a mutant of PG-1, having dimethylated Arg residues, adopts an in-plane orientation, interfacial location, and fast uniaxial motion around the membrane normal (see scheme). The less active mutant thus disrupts the membrane by in-plane diffusion, in contrast to the more active wild-type PG-1, which forms immobile transmembrane β-barrels to cause toroidal-pore membrane defects.