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bioRxiv · 10.1101/2024.08.22.609254

Visualizing Single V-ATPase Rotation Using Janus Nanoparticles

Otomo, A.·Wiemann, J.·Bhattacharyya, S.·Yamamoto, M.·Yu, Y.·Iino, R.
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Abstract

Understanding the function of rotary molecular motors, such as the rotary ATPases, relies on our ability to visualize the single-molecule rotation. Traditional imaging methods often involve tagging those motors with nanoparticles (NPs) and inferring their rotation from translational motion of NPs. Here, we report an approach using "two-faced" Janus NPs to directly image the rotation of single V-ATPase from Enterococcus hirae, an ATP-driven rotary ion pump. By employing a 500-nm silica/gold Janus NP, we exploit its asymmetric optical contrast - silica core with a gold cap on one hemisphere - to achieve precise imaging of the unidirectional counter-clockwise rotation of single V-ATPase motors immobilized on surfaces. Despite the added viscous load from the relatively large Janus NP probe, our approach provides accurate torque measurements of single V-ATPase. This study underscores the advantages of Janus NPs over conventional probes, establishing them as powerful tools for single-molecule analysis of rotary molecular motors.

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Otomo, A., Wiemann, J., Bhattacharyya, S., Yamamoto, M., Yu, Y., Iino, R.. 2024-08-22. Visualizing Single V-ATPase Rotation Using Janus Nanoparticles. https://doi.org/10.1101/2024.08.22.609254

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