By a News Reporter-Staff News Editor at Life Science Weekly -- Research findings on DNA Research are discussed in a new report. According to news reporting originating from Santa Barbara, California, by NewsRx correspondents, research stated, "We measure the stiffness of tiled DNA nanotubes (HX-tubes) as a function of their (defined) circumference by analyzing their micrometer-scale thermal deformations using fluorescence microscopy. We derive a model that relates nanoscale features of HX-tube architecture to the measured persistence lengths."
Our news editors obtained a quote from the research from the University of California, "Given the known stiffness of double-stranded DNA, we use this model to constrain the average spacing between and effective stiffness of individual DNA duplexes in the tube. A key structural feature of tiled nanotubes that can affect stiffness is their potential to form with discrete amounts of twist of the DNA duplexes about the tube axis (supertwist). We visualize the supertwist of HX-tubes using electron microscopy of gold nanoparticles, attached to specific sites along the nanotube. This method reveals that HX-tubes tend not to form with supertwist unless forced by sequence design, and, even when forced, supertwist is reduced by elastic deformations of the underlying DNA lattice. We compare the hybridization energy gained upon closing a duplex sheet into a tube with the elastic energy paid for deforming the sheet to allow closure. In estimating the elastic energy we account for bending and twisting of the individual duplexes as well as shearing between them. We find the minimum supertwist state has minimum free energy, and global untwisting of forced supertwist is energetically favorable, consistent with our experimental data. Finally, we show that attachment of Cy3 dyes or changing counterions can cause nanotubes to adopt a permanent writhe with micrometer-scale pitch and amplitude."
According to the news editors, the research concluded: "We propose that the coupling of local twist and global counter-twist may be useful in characterizing perturbations of DNA structure."
For more information on this research see: Nanoscale structure and microscale stiffness of DNA nanotubes. Acs Nano, 2013;7(8):6700-10. (American Chemical Society - www.acs.org; Acs Nano - www.pubs.acs.org/journal/ancac3)
The news editors report that additional information may be obtained by contacting D. Schiffels, Physics Department, University of California, Santa Barbara, California, United States. Additional authors for this research include T. Liedl and D.K Fygenson (see also DNA Research).
Keywords for this news article include: Nanotube, Nanoscale, California, DNA Research, Santa Barbara, United States, Nanotechnology, Emerging Technologies, North and Central America.
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC