Solid-State¹⁷O NMR as a Probe for Structural Studies of Proteins in Biomembranes

We report the first example of 17O NMR spectra from a selectively labeled transmembrane peptide, 17O-[Ala12]-WALP23, as a lyophilized powder and incorporated in hydrated phospholipid vesicles. It is shown that at high magnetic field it is feasible to apply 17O NMR to the study of membrane-incorporated peptides. Furthermore, we were able to estimate distances within the selectively labeled WALP peptide, which represents a consensus transmembrane protein sequence. This work opens up new applications of 17O solid-state NMR on biological systems.