Abstract
We present here recent results on the structure of superhelical DNA and its changes with salt concentration between 0.01 and 1.5 M NaCI. Scattering curves of two different superhelical DNAs were determined by static light scattering. The measured radii of gyration do not change significantly with salt concentration. Small-angle neutron scattering, together with calculations from a Monte-Carlo model, allows to determine the superhelix diameter. Measured and simulated scattering curves agreed almost quantitatively. Experimentally we find that the diameter decreases from (16.0±0.9) nm at 10 mM to (9.0±0.7) nm at 100 mM NaCI. The superhelix diameter from the simulated conformations decreased from (18.0±1.5) nm at 10 mM to (9.4±1.5) nm at 100 mM NaCI. At higher salt concentrations up to 1.5 M NaC1, the diameter stays constant at 9 nm
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© 1999 Springer Science+Business Media Dordrecht
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Langowski, J., Hammermann, M., Klenin, K., Tóth, K. (1999). Superhelical DNA Studied by Solution Scattering and Computer Models. In: Bradbury, E.M., Pongor, S. (eds) Structural Biology and Functional Genomics. NATO Science Series, vol 71. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-4631-9_4
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DOI: https://doi.org/10.1007/978-94-011-4631-9_4
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