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

• Published in: Nature communications Vol. 9; no. 1; pp. 4983 - 11
• Main Authors: Heath, George R., Scheuring, Simon
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26.11.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 147/3; 631/1647/2204/1262; 631/337/2265; 631/57/2270; 631/57/2271; 639/766/747; Annexin A5; Biomolecules; Cell Membrane; Diffusion; High speed; Humanities and Social Sciences; Kinetics; Membranes; Microscopes; Microscopy, Atomic Force - methods; Models, Biological; multidisciplinary; Position sensing; Rotation; Science; Science (multidisciplinary); Self-assembly; Spectroscopy; Spectrum Analysis; Staining and Labeling; Time Factors; Time-Lapse Imaging
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-07512-3

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. The dynamics of biomolecules can occur over a wide range of time and length scales. Here the authors develop a high-speed AFM height spectroscopy method to directly detect the motion of unlabeled molecules at Angstrom spatial and microsecond temporal resolution.