biostudies-literatureUnknownOtomo ANIGMS NIH HHSUnderstanding 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 <i>Enterococcus hirae</i>, 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 prbioRxiv : the preprint server for biology2024.08.22.609254https://www.ebi.ac.uk/biostudies/studies/S-EPMC11370591biostudies-literatureVisualizing Single V-ATPase Rotation Using Janus Nanoparticles.PMC11370591R35 GM124918Otomo AYamamoto MBhattacharyya SWiemann JIino RYu YfalseVisualizing Single V-ATPase Rotation Using Janus Nanoparticles.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 <i>Enterococcus hirae</i>, 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 pr2024-01-01T00:00:00Z2024 Aug2025-04-04T02:54:36.616Z2025-04-04T02:54:36.616ZS-EPMC113705913922912210.1101/2024.08.22.609254