Anomalous Rotational Dynamics of Proteins on Surfaces

April 11, 2022

Zhang PNAS graphic for highlight.JPG

(A-C) Schematic of angular states (top-panel of A-C) and HS-AFM snapshots (bottom panel of A-C) of protein nanorods in their energetically preferred orientations, corresponding to specific directions of the mineral lattice. (D) Orientational free energy landscape and heat map of relative populations at each angle determined from deep learning analysis of HS-AFM data.

Scientific Achievement

Quantified the rotational dynamics of proteins at a solid-liquid interface, revealing the coexistence of Brownian motion and non-classical jumps between minima in the orientational energy landscape.

Significance and Impact

These new insights on the dynamic processes of biomolecular assembly at solid-liquid interfaces will enable better control over synthesis of bioinspired composites and understanding of their behavior.

Research Details

  • Protein motion on a mineral surface was tracked by high-speed atomic force microscopy (HS-AFM)

  • Deep learning enabled automated analysis of energy landscapes and inter-minima transitions

  • Comparison with kinetic Monte Carlo simulations revealed two modes of rotation: Brownian motion between adjacent states and activated processes that enable large jumps between non-adjacent states.

Zhang, S., R. Sadre, B. Legg, H. Pyles, T. Perciano, W. Bethel, D. Baker, O.. Rubel, and J.J. De Yoreo. (2022). Rotational dynamics and transition mechanisms of surface-adsorbed proteins. Proc. Nat'l Acad. Sci USA  119. DOI: 10.1073/pnas.2020242119

Work was performed at Pacific Northwest National Laboratory, Lawrence Berkeley National Laboratory, and the University of Washington.