查看文章

The orientation and dynamics of an 18-residue antimicrobial peptide, ovispirin, has been investigated using solid-state NMR spectroscopy. Ovispirin is a cathelicidin-like model peptide (NH₂-KNLRRIIRKIIHIIKKYG-COOH) with potent, broad-spectrum bactericidal activity. ¹⁵N NMR spectra of oriented ovispirin reconstituted into synthetic phospholipids show that the helical peptide is predominantly oriented in the plane of the lipid bilayer, except for a small portion of the helix, possibly at the C-terminus, which deviates from the surface orientation. This suggests differential insertion of the peptide backbone into the lipid bilayer. ¹⁵N spectra of both oriented and unoriented peptides show a reduced ¹⁵N chemical shift anisotropy at room temperature compared with that of rigid proteins, indicating that the peptide undergoes uniaxial rotational diffusion around the bilayer normal with correlation times shorter than 10⁻⁴ s …