Molecular motors designed

In a film, the cooperative effort of the different molecular motors, between consecutive cross-linked points, promotes film swelling and shrinking during oxidation or reduction, respectively, producing a macroscopic change in volume (Fig. 18). In order to translate these electrochemically controlled molecular movements into macroscopic and controlled movements able to produce mechanical work, our laboratory designed, constructed, and in 1992 patented bilayer and multilayer103-114 polymeric... 

A knowledge and understanding on the nature of the helix switching may be helpful in designing PM-transition capability and characteristics in diverse screw-sense inversion related applications, such as chiroptical switches and memory, switchable chiral separation columns, molecular recognition and molecular motor applications. 

Abstract To appreciate the technological potential of controlled molecular-level motion one only has to consider that it lies at the heart of virtually every biological process. When we learn how to build synthetic molecular motors and machines that can interface their effects directly with other molecular-level sub-structures and the outside world it will add a new dimension to functional molecule and materials design. In this review we discuss both the influence of chirality on the design of molecular level machines and, in turn, how molecular level machines can control the expression of chirality of a physical response to an inherently achiral stimulus. 

Kelly TR, Silva RA, De Silva H, Jasmin S, Zhao Y (2000) A rationally designed prototype of a molecular motor. J Am Chem Soc 122 6935-6949... 

T.R. Kelly, Progress toward a Rationally Designed Molecular Motor , Acc. Chem. Res., 34,514(2001)... 

Kelly TR, Cai X, Damkaci F, Panicker SB, Tu B, Bushell SM, Cornelia I, Piggott MJ, Salives R, Cavero M, Zhao Y, Jasmin S. Progress toward a rationally designed, chemically powered rotary molecular motor. J. Am. Chem. Soc. 2007 129 376-386. 

Anabaena sensory rhodopsin (ASR, Fig. 10.2) [15, 16]—and a class [17, 18] of synthetic light-driven rotary molecular motors developed from chiral overcrowded alkenes [19], As further discussed below, verifying this analogy may have positive implications for the future design and construction of synthetic molecular motors. 

Molecular systems that exhibit controlled or coordinated rotary motion are discussed in this chapter. These systems represent a reproduction of a variety of macroscopic mechanical devices on the molecular scale. From gears to a motor, passing through a turnstile, a brake and a ratchet, we describe their design, synthesis and dynamic behavior. The importance of molecular motors in the biological realm and possible applications in nanotechnology are also discussed. 

The phosgene-promoted conversion of 47a to 47b constitutes the proof of principle of the first rationally designed, chemically powered molecular motor. Once the prototype molecular motor 47 had been shown to function as desired, we proceeded to study the rotation of the analogous molecular system 48, where the tether contains only two carbons. Based on earlier considerations (Fig. 21 and Scheme 9), one would predict that use of a shorter tether should give a pre-barrier carbamate closer in energy to the summit. Such a situation should reduce the amount of time needed for rotation to the post-barrier carbamate 52 and therefore increase the speed of rotation. 

The chemically powered unidirectional rotation of 47a to 47b constitutes a proof of principle of the first rationally designed molecular motor. Much optimization remains to be done before we achieve a molecular system that rotates continuously and rivals the speed of its biological and mechanical counterparts. The next step, however, is now clear To achieve repeated... 

Balzani, V., Credi, A., Ferrer, B., Silvi, S., Venturi, M., Artificial Molecular Motors and Machines Design Principles and Prototype Systems, Top. Curr. Chem. 2005, 262, 1 28. 

In addition to myosin, it is of interest to use the similar techniques to analyze other molecular motors in a comparative fashion. Of particular interest are kinesin and helicases, in which the chanical step occurs when the motor is bound on its tracks therefore, it is possible that somewhat different sets of constraints and structural features can be found in these motors compared to myosin. Once mechanochemical coupling is weU understood in several representative systems, it might be possible to design computational protocols that allow one to predict conformational transitions coupled to ATP binding and/or hydrolysis based on, for example, combination of experimental data at different resolutions (e.g., x-ray and electron microscopy [EM], fluorescence resonance energy transfer [FRET]) meeting this challenge can have a... 

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