Investigating Daptomycin-Membrane Interactions Using Native MS and Fast Photochemical Oxidation of Peptides in Nanodiscs

Anal Chem. 2023 Mar 21;95(11):4984-4991. doi: 10.1021/acs.analchem.2c05222. Epub 2023 Mar 8.

Abstract

Daptomycin is a cyclic lipopeptide antibiotic that targets the lipid membrane of Gram-positive bacteria. Membrane fluidity and charge can affect daptomycin activity, but its mechanisms are poorly understood because it is challenging to study daptomycin interactions within lipid bilayers. Here, we combined native mass spectrometry (MS) and fast photochemical oxidation of peptides (FPOP) to study daptomycin-membrane interactions with different lipid bilayer nanodiscs. Native MS suggests that daptomycin incorporates randomly and does not prefer any specific oligomeric states when integrated into bilayers. FPOP reveals significant protection in most bilayer environments. Combining the native MS and FPOP results, we observed that stronger membrane interactions are formed with more rigid membranes, and pore formation may occur in more fluid membranes to expose daptomycin to FPOP oxidation. Electrophysiology measurements further supported the observation of polydisperse pore complexes from the MS data. Together, these results demonstrate the complementarity of native MS, FPOP, and membrane conductance experiments to shed light on how antibiotic peptides interact with and within lipid membranes.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Daptomycin*
  • Lipid Bilayers / chemistry
  • Mass Spectrometry

Substances

  • Anti-Bacterial Agents
  • Daptomycin
  • Lipid Bilayers