Single molecule manipulation

Because this problem is complex several avenues of attack have been devised in the last fifteen years. A combination of experimental developments (protein engineering, advances in x-ray and nuclear magnetic resonance (NMR), various time-resolved spectroscopies, single molecule manipulation methods) and theoretical approaches (use of statistical mechanics, different computational strategies, use of simple models) [5, 6 and 7] has led to a greater understanding of how polypeptide chains reach the native confonnation. 

PROPERTIES OF SINGLE MOLECULES MANIPULATION, DISSOCIATION AND SYNTHESIS WITH THE SCANNING TUNNELING MICROSCOPE... 

In the following section, the synthesis of a biphenyl molecule from two iodobenzene molecules adsorbed on a Cu(lll) surface using single molecule manipulation techniques with the STM-tip is presented as example. 

An even more difficult task in the field of single-molecule manipulation is that of causing a combined translational and rotational movement. For this purpose,... 

Single-Molecule Manipulation of DNA Optical traps and micropipettes are used to hold and to stretch single molecules of DNA, showing how the folded strand behaves as an entropic spring. 

The advent of methods of single molecule manipulation [6,7] and single molecule detection [8-10] have made it possible for the first time to follow the molecular trajectories of these motors and describe in increasing detail their dynamics. The variables that are more easily detected by these methods are force, displacement, and time. These quantities are also the ones of greatest functional value to understand the mechanochemical operation of these motors. 

K.-F. Braun, S.-W. Hla, Properties of Single Molecules Manipulation, Dissociation and- Synthesis with the Scanning Tunnelling Microscope in Properties of Single Molecules on Crystal Surfaces, F. Rosei (Ed.), Imperial College Press/American Scientific Publishers, London 2004. 

In the last few years, however, the outstanding development of single molecule manipulation and observation, particularly by fluorescence spectroscopy, has thrown some light on the operational mechanism of several biological machines. For example, it was shown that ATP synthase, the enzyme that manufactures adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and inorganic phosphate (Pi) is powered by a rotary motor fueled by a proton gradient (Fig. 1). The asymmetric membrane-spanning Fq portion of the enzyme contains a proton channel, and the soluble F] portion contains three catalytic sites that cooperate in the... 

In contrast to electron-beam lithography, the mechanism of STM lithography is generally an inelastic electron tunneling process, with energy quanta of an electron volt. STM can also be used for single-atom or single-molecule manipulations for the fabrication of individual nanostructures. 

L. Zheng, S. Li, P. J. Burke, J. P. Brody, Towards single molecule manipulation with dielectrophoresis using nanoelectrodes. Proceedings of the Third IEEE Conference on Nanotechnology, 2003,1, pp. 437-440. 

The birth of microfluidic devices was seen as an answer to the question of how to provide quicker chemical analysis, use fewer reagents, generate less waste, and hence enable the use of low-cost devices. A major topic of interest today is to decrease the dimensions of fluidic devices, from microfluidic to nanofluidic, to enhance the advantages outlined earlier while addressing questions related to fundamental phenomena of single-molecule manipulation, fluidic transport, and molecular behavior at the nanoscale. 

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