The Experts below are selected from a list of 19053 Experts worldwide ranked by ideXlab platform
Ben L. Feringa - One of the best experts on this subject based on the ideXlab platform.
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dynamic assemblies of Molecular Motor amphiphiles control macroscopic foam properties
Journal of the American Chemical Society, 2020Co-Authors: Shaoyu Chen, Marc C A Stuart, Franco Kingchi Leung, Chaoxia Wang, Ben L. FeringaAbstract:Stimuli-responsive supraMolecular assemblies controlling macroscopic transformations with high structural fluidity, i.e., foam properties, have attractive prospects for applications in soft materia...
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light gated rotation in a Molecular Motor functionalized with a dithienylethene switch
Angewandte Chemie, 2018Co-Authors: Diederik Roke, Constantin Stuckhardt, Wojciech Danowski, Sander J Wezenberg, Ben L. FeringaAbstract:: A multiphotochromic hybrid system is presented in which a light-driven overcrowded alkene-based Molecular rotary Motor is connected to a dithienylethene photoswitch. Ring closing of the dithienylethene moiety, using an irradiation wavelength different from the wavelength applied to operate the Molecular Motor, results in inhibition of the rotary motion as is demonstrated by detailed 1 H-NMR and UV/Vis experiments. For the first time, a light-gated Molecular Motor is thus obtained. Furthermore, the excitation wavelength of the Molecular Motor is red-shifted from the UV into the visible-light region upon attachment of the dithienylethene switch.
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solvent mixing to induce Molecular Motor aggregation into bowl shaped particles underlying mechanism particle nature and application to control Motor behavior
Journal of the American Chemical Society, 2018Co-Authors: Linda E Franken, Jiawen Chen, Egbert J Boekema, Depeng Zhao, Marc C A Stuart, Ben L. FeringaAbstract:Control over dynamic functions in larger assemblies is key to many Molecular systems, ranging from responsive materials to Molecular machines. Here we report a Molecular Motor that forms bowl-shaped particles in water and how confinement of the Molecular Motor affects rotary motion. Studying the aggregation process in a broader context, we provide evidence that, in the case of bowl-shaped particles, the structures are not the product of self-assembly, but a direct result of the mixing a good solvent and a (partial) non-solvent and highly independent of the Molecular design. Under the influence of the non-solvent, droplets are formed, of which the exterior is hardened due to the increase in the glass transition temperature by the external medium, while the interior of the droplets remains plasticized by the solvent, resulting in the formation of stable bowl-shaped particles with a fluid interior, a glass-like exterior, and a very specific shape: dense spheres with a hole in their side. Applying this to a b...
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photoswitching of dna hybridization using a Molecular Motor
Journal of the American Chemical Society, 2018Co-Authors: Anouk S Lubbe, Sanne J Smith, Jan Willem De Vries, Jos C M Kistemaker, Alex H De Vries, Ignacio Faustino, Zhuojun Meng, Wiktor Szymanski, Andreas Herrmann, Ben L. FeringaAbstract:Reversible control over the functionality of biological systems via external triggers may be used in future medicine to reduce the need for invasive procedures. Additionally, externally regulated biomacromolecules are now considered as particularly attractive tools in nanoscience and the design of smart materials, due to their highly programmable nature and complex functionality. Incorporation of photoswitches into biomolecules, such as peptides, antibiotics, and nucleic acids, has generated exciting results in the past few years. Molecular Motors offer the potential for new and more precise methods of photoregulation, due to their multistate switching cycle, unidirectionality of rotation, and helicity inversion during the rotational steps. Aided by computational studies, we designed and synthesized a photoswitchable DNA hairpin, in which a Molecular Motor serves as the bridgehead unit. After it was determined that Motor function was not affected by the rigid arms of the linker, solid-phase synthesis was ...
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locked synchronous rotor motion in a Molecular Motor
Science, 2017Co-Authors: Peter Stacko, Jos C M Kistemaker, Thomas Van Leeuwen, Muchieh Chang, Edwin Otten, Ben L. FeringaAbstract:Biological Molecular Motors translate their local directional motion into ordered movement of other parts of the system to empower controlled mechanical functions. The design of analogous geared systems that couple motion in a directional manner, which is pivotal for Molecular machinery operating at the nanoscale, remains highly challenging. Here, we report a Molecular rotary Motor that translates light-driven unidirectional rotary motion to controlled movement of a connected biaryl rotor. Achieving coupled motion of the distinct parts of this multicomponent mechanical system required precise control of multiple kinetic barriers for isomerization and synchronous motion, resulting in sliding and rotation during a full rotary cycle, with the Motor always facing the same face of the rotor.
Michael M Pollard - One of the best experts on this subject based on the ideXlab platform.
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Driving Unidirectional Molecular Rotary Motors with Visible Light by Intra- And InterMolecular Energy Transfer from Palladium Porphyrin
Journal of the American Chemical Society, 2012Co-Authors: Arjen Cnossen, Michael M Pollard, Philana V. Wesenhagen, Wesley R. Browne, Ben L. FeringaAbstract:Driving Molecular rotary Motors using visible light (530–550 nm) instead of UV light was achieved using palladium tetraphenylporphyrin as a triplet sensitizer. Visible light driven rotation was confirmed by UV/vis absorption, circular dichroism and 1H NMR spectroscopy and the rotation was confirmed to be unidirectional and with similar photostationary states, despite proceeding via a triplet instead of a singlet excited state of the Molecular Motor. Energy transfer proceeds in both inter- and intraMolecular fashion from the triplet state of the porphyrin to the Motor. Stern Volmer plots show that the rate of interMolecular quenching of the porphyrin excited state by the Molecular Motor is diffusion-controlled.
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reversing the direction in a light driven rotary Molecular Motor
Nature Chemistry, 2011Co-Authors: Nopporn Ruangsupapichat, Michael M Pollard, Syuzanna R Harutyunyan, Ben L. FeringaAbstract:Biological rotary Motors can alter their mechanical function by changing the direction of rotary motion. Now, researchers have designed a synthetic light-driven rotary Motor in which the direction of rotation can be reversed on command by changing the chirality of the Molecular Motor through base-induced epimerization.
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Reversing the direction in a light-driven rotary Molecular Motor
Nature Chemistry, 2011Co-Authors: Nopporn Ruangsupapichat, Michael M Pollard, Syuzanna R Harutyunyan, Ben L. FeringaAbstract:Biological rotary Motors can alter their mechanical function by changing the direction of rotary motion. Now, researchers have designed a synthetic light-driven rotary Motor in which the direction of rotation can be reversed on command by changing the chirality of the Molecular Motor through base-induced epimerization. Biological rotary Motors can alter their mechanical function by changing the direction of rotary motion. Achieving a similar reversal of direction of rotation in artificial Molecular Motors presents a fundamental stereochemical challenge: how to change from clockwise to anticlockwise motion without compromising the autonomous unidirectional rotary behaviour of the system. A new Molecular Motor with multilevel control of rotary motion is reported here, in which the direction of light-powered rotation can be reversed by base-catalysed epimerization. The key steps are deprotonation and reprotonation of the photochemically generated less-stable isomers during the 360° unidirectional rotary cycle, with complete inversion of the configuration at the stereogenic centre. The ability to change directionality is an essential step towards mechanical Molecular systems with adaptive functional behaviour.
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reversing the direction in a light driven rotary Molecular Motor
Nature Chemistry, 2011Co-Authors: Nopporn Ruangsupapichat, Michael M Pollard, Syuzanna R Harutyunyan, Ben L. FeringaAbstract:Biological rotary Motors can alter their mechanical function by changing the direction of rotary motion. Achieving a similar reversal of direction of rotation in artificial Molecular Motors presents a fundamental stereochemical challenge: how to change from clockwise to anticlockwise motion without compromising the autonomous unidirectional rotary behaviour of the system. A new Molecular Motor with multilevel control of rotary motion is reported here, in which the direction of light-powered rotation can be reversed by base-catalysed epimerization. The key steps are deprotonation and reprotonation of the photochemically generated less-stable isomers during the 360° unidirectional rotary cycle, with complete inversion of the configuration at the stereogenic centre. The ability to change directionality is an essential step towards mechanical Molecular systems with adaptive functional behaviour.
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Light-driven altitudinal Molecular Motors on surfaces
Chemical Communications, 2009Co-Authors: Gabor London, Michael M Pollard, Gregory T. Carroll, Tatiana Fernandez Landaluce, Petra Rudolf, Ben L. FeringaAbstract:A Cu(I)-catalyzed 1,3-dipolar cycloaddition was used to construct a monolayer of an altitudinal Molecular Motor on quartz and silicon substrates, which represents the fastest light-driven Molecular Motor, to date, grafted to a solid surface.
George T. Shubeita - One of the best experts on this subject based on the ideXlab platform.
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measuring Molecular Motor forces in vivo implications for tug of war models of bidirectional transport
Biophysical Journal, 2012Co-Authors: Christina Leidel, Rafael A. Longoria, Franciso Marquez Gutierrez, George T. ShubeitaAbstract:Molecular Motor proteins use the energy released from ATP hydrolysis to generate force and haul cargoes along cytoskeletal filaments. Thus, measuring the force Motors generate amounts to directly probing their function. We report on optical trapping methodology capable of making precise in vivo stall-force measurements of individual cargoes hauled by Molecular Motors in their native environment. Despite routine measurement of Motor forces in vitro, performing and calibrating such measurements in vivo has been challenging. We describe the methodology recently developed to overcome these difficulties, and used to measure stall forces of both kinesin-1 and cytoplasmic dynein-driven lipid droplets in Drosophila embryos. Critically, by measuring the cargo dynamics in the optical trap, we find that there is memory: it is more likely for a cargo to resume motion in the same direction—rather than reverse direction—after the Motors transporting it detach from the microtubule under the force of the optical trap. This suggests that only Motors of one polarity are active on the cargo at any instant in time and is not consistent with the tug-of-war models of bidirectional transport where both polarity Motors can bind the microtubules at all times. We further use the optical trap to measure in vivo the detachment rates from microtubules of kinesin-1 and dynein-driven lipid droplets. Unlike what is commonly assumed, we find that dynein’s but not kinesin’s detachment time in vivo increases with opposing load. This suggests that dynein’s interaction with microtubules behaves like a catch bond.
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Measuring Molecular Motor forces in VIVO: Implications for tug-of-war models of bidirectional transport
Biophysical Journal, 2012Co-Authors: Christina Leidel, Rafael A. Longoria, Franciso Marquez Gutierrez, George T. ShubeitaAbstract:Molecular Motor proteins use the energy released from ATP hydrolysis to generate force and haul cargoes along cytoskeletal filaments. Thus, measuring the force Motors generate amounts to directly probing their function. We report on optical trapping methodology capable of making precise in vivo stall-force measurements of individual cargoes hauled by Molecular Motors in their native environment. Despite routine measurement of Motor forces in vitro, performing and calibrating such measurements in vivo has been challenging. We describe the methodology recently developed to overcome these difficulties, and used to measure stall forces of both kinesin-1 and cytoplasmic dynein-driven lipid droplets in Drosophila embryos. Critically, by measuring the cargo dynamics in the optical trap, we find that there is memory: it is more likely for a cargo to resume motion in the same direction - rather than reverse direction - after the Motors transporting it detach from the microtubule under the force of the optical trap. This suggests that only Motors of one polarity are active on the cargo at any instant in time and is not consistent with the tug-of-war models of bidirectional transport where both polarity Motors can bind the microtubules at all times. We further use the optical trap to measure in vivo the detachment rates from microtubules of kinesin-1 and dynein-driven lipid droplets. Unlike what is commonly assumed, we find that dynein's but not kinesin's detachment time in vivo increases with opposing load. This suggests that dynein's interaction with microtubules behaves like a catch bond. © 2012 by the Biophysical Society.
Richard A Van Delden - One of the best experts on this subject based on the ideXlab platform.
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acceleration of a nanoMotor electronic control of the rotary speed of a light driven Molecular rotor
Journal of the American Chemical Society, 2005Co-Authors: Dirk Pijper, Bernard Feringa, R A Van Delden, Auke Meetsma, Richard A Van DeldenAbstract:A new second-generation light-driven Molecular Motor was designed, in which the presence of a potential electronic push−pull system leads to a significant increase of the rate of rotation compared to previous Motor systems, without disturbing its overall unidirectionality.
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unidirectional Molecular Motor on a gold surface
Nature, 2005Co-Authors: Richard A Van Delden, Michael M Pollard, Matthijs K J Ter Wiel, Javier Vicario, Nagatoshi Koumura, Ben L. FeringaAbstract:Molecules capable of mimicking the function of a wide range of mechanical devices have been fabricated, with Motors that can induce mechanical movement attracting particular attention1,2. Such Molecular Motors convert light or chemical energy into directional rotary or linear motion2,3,4,5,6,7,8,9,10, and are usually prepared and operated in solution. But if they are to be used as nanomachines that can do useful work, it seems essential to construct systems that can function on a surface, like a recently reported linear artificial muscle11. Surface-mounted rotors have been realized and limited directionality in their motion predicted12,13. Here we demonstrate that a light-driven Molecular Motor capable of repetitive unidirectional rotation14 can be mounted on the surface of gold nanoparticles. The Motor design14 uses a chiral helical alkene with an upper half that serves as a propeller and is connected through a carbon–carbon double bond (the rotation axis) to a lower half that serves as a stator. The stator carries two thiol-functionalized ‘legs’, which then bind the entire Motor molecule to a gold surface. NMR spectroscopy reveals that two photo-induced cis-trans isomerizations of the central double bond, each followed by a thermal helix inversion to prevent reverse rotation, induce a full and unidirectional 360° rotation of the propeller with respect to the surface-mounted lower half of the system.
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increased speed of rotation for the smallest light driven Molecular Motor
Journal of the American Chemical Society, 2003Co-Authors: Matthijs K J Ter Wiel, Richard A Van Delden, And Auke Meetsma, Ben L. FeringaAbstract:In this paper we present the smallest artificial light-driven Molecular Motor consisting of only 28 carbon and 24 hydrogen atoms. The concept of controlling directionality of rotary movement at the Molecular level by introduction of a stereogenic center next to the central olefinic bond of a sterically overcrowded alkene does not only hold for Molecular Motors with six-membered rings, but is also applicable to achieve the unidirectional movement for Molecular Motors having five-membered rings. Although X-ray analyses show that the five-membered rings in the cis- and trans-isomer of the new Molecular Motor are nearly flat, the energy differences between the (pseudo-)diaxial and (pseudo-)diequatorial conformations of the methyl substituents in both isomers are still large enough to direct the rotation of one-half of the molecule with respect to the other half in a clockwise fashion. The full rotary cycle comprises four consecutive steps: two photochemical isomerizations each followed by a thermal helix inversion. Both photochemical cis-trans isomerizations proceed with a preference for the unstable diequatorial isomers over the stable diaxial isomers. The thermal barriers for helix inversion of this Motor molecule have decreased dramatically compared to its six-membered ring analogue, the half-life of the fastest step being only 18 s at room temperature.
Tomokazu Matsue - One of the best experts on this subject based on the ideXlab platform.
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Molecular Motor-powered shuttles along multi-walled carbon nanotube tracks
Nano Letters, 2014Co-Authors: Aurélien Sikora, Kyongwan Kim, Kelley Reaves, Hikaru Nakazawa, Javier Ramón-azcón, Hitoshi Shiku, Izumi Kumagai, Mitsuo Umetsu, Tadafumi Adschiri, Tomokazu MatsueAbstract:As a complementary tool to nanofluidics, bioMolecular-based transport is envisioned for nanotechnological devices. We report a new method for guiding microtubule shuttles on multi-walled carbon nanotube tracks, aligned by dielectrophoresis on a functionalized surface. In the absence of electric field and in fluid flow, alignment is maintained. The directed translocation of kinesin propelled microtubules has been investigated using fluorescence microscopy. To our knowledge, this is the first demonstration of microtubules gliding along carbon nanotubes.
