scholarly journals Thermodynamic analysis of F1 -ATPase rotary catalysis using high-speed imaging

2014 ◽  
Vol 23 (12) ◽  
pp. 1773-1779 ◽  
Author(s):  
Rikiya Watanabe ◽  
Yoshihiro Minagawa ◽  
Hiroyuki Noji
Keyword(s):  
Thermodynamic Analysis ◽  
High Speed ◽  
High Speed Imaging ◽  
F1 Atpase ◽  
Rotary Catalysis

scholarly journals Direct Observation of Rotary Catalysis of Rotorless F1-ATPase by High-Speed Atomic Force Microscopy

2012 ◽  
Vol 102 (3) ◽  
pp. 600a
Author(s):  
Ryota Iino ◽  
Takayuki Uchihashi ◽  
Toshio Ando ◽  
Hiroyuki Noji
Keyword(s):  
Atomic Force Microscopy ◽  
Direct Observation ◽  
High Speed ◽  
Force Microscopy ◽  
F1 Atpase ◽  
Atomic Force ◽  
Rotary Catalysis

scholarly journals Rotary catalysis of bovine mitochondrial F1-ATPase studied by single-molecule experiments

2020 ◽  
Vol 117 (3) ◽  
pp. 1447-1456 ◽  
Author(s):  
Ryohei Kobayashi ◽  
Hiroshi Ueno ◽  
Chun-Biu Li ◽  
Hiroyuki Noji
Keyword(s):  
Single Molecule ◽  
High Speed ◽  
Atp Hydrolysis ◽  
Angular Position ◽  
Magnetic Tweezers ◽  
Reaction Scheme ◽  
Atp Binding ◽  
High Speed Imaging ◽  
Hydrolysis Process ◽  
Rotary Catalysis

The reaction scheme of rotary catalysis and the torque generation mechanism of bovine mitochondrial F1 (bMF1) were studied in single-molecule experiments. Under ATP-saturated concentrations, high-speed imaging of a single 40-nm gold bead attached to the γ subunit of bMF1 showed 2 types of intervening pauses during the rotation that were discriminated by short dwell and long dwell. Using ATPγS as a slowly hydrolyzing ATP derivative as well as using a functional mutant βE188D with slowed ATP hydrolysis, the 2 pausing events were distinctively identified. Buffer-exchange experiments with a nonhydrolyzable analog (AMP-PNP) revealed that the long dwell corresponds to the catalytic dwell, that is, the waiting state for hydrolysis, while it remains elusive which catalytic state short pause represents. The angular position of catalytic dwell was determined to be at +80° from the ATP-binding angle, mostly consistent with other F1s. The position of short dwell was found at 50 to 60° from catalytic dwell, that is, +10 to 20° from the ATP-binding angle. This is a distinct difference from human mitochondrial F1, which also shows intervening dwell that probably corresponds to the short dwell of bMF1, at +65° from the binding pause. Furthermore, we conducted “stall-and-release” experiments with magnetic tweezers to reveal how the binding affinity and hydrolysis equilibrium are modulated by the γ rotation. Similar to thermophilic F1, bMF1 showed a strong exponential increase in ATP affinity, while the hydrolysis equilibrium did not change significantly. This indicates that the ATP binding process generates larger torque than the hydrolysis process.

scholarly journals High-Speed Atomic Force Microscopy Reveals Rotary Catalysis of Rotorless F1-ATPase

Science ◽  
2011 ◽  
Vol 333 (6043) ◽  
pp. 755-758 ◽  
Author(s):  
T. Uchihashi ◽  
R. Iino ◽  
T. Ando ◽  
H. Noji
Keyword(s):  
Atomic Force Microscopy ◽  
High Speed ◽  
Force Microscopy ◽  
F1 Atpase ◽  
Atomic Force ◽  
Rotary Catalysis

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

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