Chemical Additives Enable Native Mass Spectrometry Measurement of Membrane Protein Oligomeric State within Intact Nanodiscs

J Am Chem Soc. 2019 Jan 16;141(2):1054-1061. doi: 10.1021/jacs.8b11529. Epub 2019 Jan 7.


Membrane proteins play critical biochemical roles but remain challenging to study. Recently, native or nondenaturing mass spectrometry (MS) has made great strides in characterizing membrane protein interactions. However, conventional native MS relies on detergent micelles, which may disrupt natural interactions. Lipoprotein nanodiscs provide a platform to present membrane proteins for native MS within a lipid bilayer environment, but previous native MS of membrane proteins in nanodiscs has been limited by the intermediate stability of nanodiscs. It is difficult to eject membrane proteins from nanodiscs for native MS but also difficult to retain intact nanodisc complexes with membrane proteins inside. Here, we employed chemical reagents that modulate the charge acquired during electrospray ionization (ESI). By modulating ESI conditions, we could either eject the membrane protein complex with few bound lipids or capture the intact membrane protein nanodisc complex-allowing measurement of the membrane protein oligomeric state within an intact lipid bilayer environment. The dramatic differences in the stability of nanodiscs under different ESI conditions opens new applications for native MS of nanodiscs.

Publication types

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

MeSH terms

  • Aquaporins / chemistry*
  • Cation Transport Proteins / chemistry*
  • Dioxolanes / chemistry
  • Escherichia coli / chemistry
  • Escherichia coli Proteins / chemistry*
  • Glycerol / analogs & derivatives
  • Imidazoles / chemistry
  • Indicators and Reagents / chemistry
  • Lipid Bilayers / chemistry
  • Nanostructures / chemistry*
  • Phosphatidylcholines / chemistry
  • Phosphatidylglycerols / chemistry
  • Propane / analogs & derivatives
  • Propane / chemistry
  • Protein Multimerization
  • Spectrometry, Mass, Electrospray Ionization / methods
  • Static Electricity


  • AmtB protein, E coli
  • Aquaporins
  • Cation Transport Proteins
  • Dioxolanes
  • Escherichia coli Proteins
  • Imidazoles
  • Indicators and Reagents
  • Lipid Bilayers
  • Phosphatidylcholines
  • Phosphatidylglycerols
  • aqpZ protein, E coli
  • imidazole
  • 1-palmitoyl-2-oleoylglycero-3-phosphoglycerol
  • propylene carbonate
  • Glycerol
  • Propane
  • 1-palmitoyl-2-oleoylphosphatidylcholine