High-speed AFM height spectroscopy reveals µs-dynamics of unlabeled biomolecules

Nat Commun. 2018 Nov 26;9(1):4983. doi: 10.1038/s41467-018-07512-3.

Abstract

Dynamics are fundamental to the functions of biomolecules and can occur on a wide range of time and length scales. Here we develop and apply high-speed AFM height spectroscopy (HS-AFM-HS), a technique whereby we monitor the sensing of a HS-AFM tip at a fixed position to directly detect the motions of unlabeled molecules underneath. This gives Angstrom spatial and microsecond temporal resolutions. In conjunction with HS-AFM imaging modes to precisely locate areas of interest, HS-AFM-HS measures simultaneously surface concentrations, diffusion coefficients and oligomer sizes of annexin-V on model membranes to decipher key kinetics allowing us to describe the entire annexin-V membrane-association and self-assembly process in great detail and quantitatively. This work displays how HS-AFM-HS can assess the dynamics of unlabeled bio-molecules over several orders of magnitude and separate the various dynamic components spatiotemporally.

MeSH terms

  • Annexin A5
  • Cell Membrane
  • Diffusion
  • Microscopy, Atomic Force / methods*
  • Models, Biological
  • Rotation
  • Spectrum Analysis*
  • Staining and Labeling*
  • Time Factors
  • Time-Lapse Imaging

Substances

  • Annexin A5