Looking at long molecules in solution: What happens when they are subjected to Couette flow?

Department of Chemistry, University of Warwick, Coventry, UKCV4 7AL.
Physical Chemistry Chemical Physics (Impact Factor: 4.49). 08/2006; 8(27):3161-71. DOI: 10.1039/b604810m
Source: PubMed


Knowing the structure of a molecule is one of the keys to deducing its function in a biological system. However, many biomacromolecules are not amenable to structural characterisation by the powerful techniques often used namely NMR and X-ray diffraction because they are too large, or too flexible or simply refuse to crystallize. Long molecules such as DNA and fibrous proteins are two such classes of molecule. In this article the extent to which flow linear dichroism (LD) can be used to characterise the structure and function of such molecules is reviewed. Consideration is given to the issues of fluid dynamics and light scattering by such large molecules. A range of applications of LD are reviewed including (i) fibrous proteins with particular attention being given to actin; (ii) a far from comprehensive discussion of the use of LD for DNA and DNA-ligand systems; (iii) LD for the kinetics of restriction digestion of circular supercoiled DNA; and (iv) carbon nanotubes to illustrate that LD can be used on any long molecules with accessible absorption transitions.

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Available from: Michael A Geeves, Sep 30, 2015
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    • "The alignment of the Waltz peptide fibrils in the initial CD experiments was the result of sample loading. This cannot be controlled and so we chose to measure the LD signals using a micro-volume Couette flow cell apparatus [39] as this provides a reproducible alignment methodology to gain more information regarding the orientation of structural elements and chromophores within the amyloid fibrils. "
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