Mass photometry enables label-free tracking and mass measurement of single proteins on lipid bilayers

Eric D B Foley1, Manish S Kushwah1, Gavin Young1,2, Philipp Kukura3

  1. Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, UK.
  2. Refeyn Ltd, Oxford, UK.
  3. Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, UK. philipp.kukura@chem.ox.ac.uk.

Abstract

The quantification of membrane-associated biomolecular interactions is crucial to our understanding of various cellular processes. State-of-the-art single-molecule approaches rely largely on the addition of fluorescent labels, which complicates the quantification of the involved stoichiometries and dynamics because of low temporal resolution and the inherent limitations associated with labeling efficiency, photoblinking and photobleaching. Here, we demonstrate dynamic mass photometry, a method for label-free imaging, tracking and mass measurement of individual membrane-associated proteins diffusing on supported lipid bilayers. Application of this method to the membrane remodeling GTPase, dynamin-1, reveals heterogeneous mixtures of dimer-based oligomers, oligomer-dependent mobilities, membrane affinities and (dis)association of individual complexes. These capabilities, together with assay-based advances for studying integral membrane proteins, will enable the elucidation of biomolecular mechanisms in and on lipid bilayers.

Presented By Eric Foley | ORCID iD

Biochemistry, BiotechnologyNicholas Liao2021-10 (Oct)