The Experts below are selected from a list of 82560 Experts worldwide ranked by ideXlab platform
Metin Sitti - One of the best experts on this subject based on the ideXlab platform.
-
Mechanical Coupling of puller and pusher active microswimmers influences motility
Langmuir, 2020Co-Authors: Ajay Singh, Vimal Kishore, Giulia Santomauro, Oncay Yasa, Joachim Bill, Metin SittiAbstract:Active self-propelled colloidal populations induce time-dependent three-dimensional fluid flows, which alter the rheological (viscoelastic) properties of their fluidic media. Researchers have also ...
Martin Karplus - One of the best experts on this subject based on the ideXlab platform.
-
Mechanical Coupling in myosin v a simulation study
Journal of Molecular Biology, 2010Co-Authors: Victor Ovchinnikov, Bernhardt L Trout, Martin KarplusAbstract:Abstract Myosin motor function depends on the interaction between different domains that transmit information from one part of the molecule to another. The interdomain Coupling in myosin V is studied with restrained targeted molecular dynamics using an all-atom representation in explicit solvent. To elucidate the origin of the conformational change due to the binding of ATP, targeting forces are applied to small sets of atoms (the forcing sets, FSs) in the direction of their displacement from the rigor conformation, which has a closed actin-binding cleft, to the post-rigor conformation, in which the cleft is open. The “minimal” FS that results in extensive structural changes in the overall myosin conformation is composed of ATP, switch 1, and the nearby HF, HG, and HH helices. Addition of switch 2 to the FS is required to achieve a complete opening of the actin-binding cleft. The restrained targeted molecular dynamics simulations reveal the Mechanical Coupling pathways between (i) the nucleotide-binding pocket (NBP) and the actin-binding cleft, (ii) the NBP and the converter, and (iii) the actin-binding cleft and the converter. Closing of the NBP due to ATP binding is tightly coupled to the opening of the cleft and leads to the rupture of a key hydrogen bond (F441N/A684O) between switch 2 and the SH1 helix. The actin-binding cleft may mediate the rupture of this bond via a connection between the HW helix, the relay helix, and switch 2. The findings are consistent with experimental studies and a recent normal mode analysis. The present method is expected to be useful more generally in studies of interdomain Coupling in proteins.
G K Padhy - One of the best experts on this subject based on the ideXlab platform.
-
effect of ultrasonic vibration on welding load temperature and material flow in friction stir welding
Journal of Materials Processing Technology, 2017Co-Authors: Y B Zhong, C S Wu, G K PadhyAbstract:Abstract The main process variables were measured, characterized and compared in friction stir welding with/without ultrasonic vibration. The exerted ultrasonic vibration causes reduction in traverse force, tool torque and axial force of welding. Based on the measurement of thermal cycles in friction stir welding process, the thermal effect of ultrasonic vibration is negligible, and the Mechanical Coupling between ultrasonic vibration and tool action plays a more important role in affecting both the welding process effectiveness and the joint quality. Ultrasonic vibrations improved weld formation by either reducing or eliminating the weld defects, and the suitable process-parameter window is expanded. Dissimilar welding of AA6061-T6 to AA2024-T3 with ultrasonic vibration was used to characterize the enhanced material flow which results in the better weld formation.
Edward P Debold - One of the best experts on this subject based on the ideXlab platform.
-
Mechanical Coupling between myosin molecules causes differences between ensemble and single molecule measurements
Biophysical Journal, 2012Co-Authors: Sam Walcott, David M Warshaw, Edward P DeboldAbstract:In contracting muscle, individual myosin molecules function as part of a large ensemble, hydrolyzing ATP to power the relative sliding of actin filaments. The technological advances that have enabled direct observation and manipulation of single molecules, including recent experiments that have explored myosin's force-dependent properties, provide detailed insight into the kinetics of myosin's mechanochemical interaction with actin. However, it has been difficult to reconcile these single-molecule observations with the behavior of myosin in an ensemble. Here, using a combination of simulations and theory, we show that the kinetic mechanism derived from single-molecule experiments describes ensemble behavior; but the connec- tion between single molecule and ensemble is complex. In particular, even in the absence of external force, internal forces generated between myosin molecules in a large ensemble accelerate ADP release and increase how far actin moves during a single myosin attachment. These myosin-induced changes in strong binding lifetime and attachment distance cause measur- able properties, such as actin speed in the motility assay, to vary depending on the number of myosin molecules interacting with an actin filament. This ensemble-size effect challenges the simple detachment limited model of motility, because even when motility speed is limited by ADP release, increasing attachment rate can increase motility speed.
Ajay Singh - One of the best experts on this subject based on the ideXlab platform.
-
Mechanical Coupling of puller and pusher active microswimmers influences motility
Langmuir, 2020Co-Authors: Ajay Singh, Vimal Kishore, Giulia Santomauro, Oncay Yasa, Joachim Bill, Metin SittiAbstract:Active self-propelled colloidal populations induce time-dependent three-dimensional fluid flows, which alter the rheological (viscoelastic) properties of their fluidic media. Researchers have also ...
