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Contributions des nanotechnologies à l'étude et à l'assemblage du Nano-Moteur flagellaire des bacteries

Abstract : The bacteria flagellar nanomotor is a nature marvellous due to its structure and importance for bacteria's. it allows the rotation at high frequency ( 300 Hz) of a long external filament. This filament plays a role comparable to a submarine helix and propels its host in the liquid environment. Despite its size, 45 nm at the largest diameter, this nano-bio-machine is composed of thousands of proteins, the primary and essential brick of evoluated life form. These proteins work together in order to generate the flagellar rotation and permit to the bacteria to swim freely in the liquid environment. Despite its importance in the bacteria life, its precise mechanism remains unclear today. Its discovery more than 3o years ago allows the accumulation of experimental data and hypotheses about its structure and mechanism. The overall assembly, the crystal structure of few of its proteins, and the role played by part of these proteins permit to draw a possible architecture of the motor. Others experiments has also highlighted some crucial aspects of this machine, through mechanical measurement of the torque developed by the motor, in order to define the torque/speed relationship. However, the nanoscale description of the motor remains limited and interpretations under precautious. In this work, I have developed two ambitious parallel and complementary ways to address this challenge: the re-assembly in a control maner in vitro of an essential part of the motor, and a large scale study of the interactions between identified motor's proteins crucial for the motor rotation. These approaches have been supported by the use of new tools, which have never been used before for studying this nano-motor: the Atomic Force Microscope (AFM), for visualizing in a close native environment part of the motor reassembled, and the Quartz Micro Balance for the interactions study. New experimental datas have been obtained and permitted to propose a new hypothese of the mechanism of the Bacteria F lagellar Nano-Motor.
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Submitted on : Thursday, April 1, 2010 - 9:31:51 AM
Last modification on : Monday, July 4, 2022 - 9:04:13 AM
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  • HAL Id : tel-00468919, version 1

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Jerôme Chalmeau. Contributions des nanotechnologies à l'étude et à l'assemblage du Nano-Moteur flagellaire des bacteries. Micro and nanotechnologies/Microelectronics. INSA de Toulouse, 2009. English. ⟨tel-00468919⟩

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