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Title: Interactions of heavy metal pollutants with dna of some bacteria
Researcher: Rao, Bandaru Chandra Sekhar
Guide(s): Devanna N
Muralidhar Rao D
Keywords: DNA
Heavy metals
Upload Date: 5-Jul-2013
University: Jawaharlal Nehru Technological University, Anantapuram
Completed Date: 30/08/2012
Abstract: M-DNA is a complex between DNA and cobalt (II), nickel (II) or zinc (II) that forms under alkaline conditions. It has been postulated that the imino proton of guanine or thymine is replaced by the metal cation in each base-pair. The complex is thought to maintain a double-helical structure similar to B-DNA but has unusual properties. M-DNA acts as an electron conductor making it a potential candidate for future nanotechnology applications. In this work the interactions of cobalt (II), nickel (II) and zinc (II) with DNA were studied. This was done in order to gain knowledge concerning the interactions of these metal cations with B-DNA and to assess aspects of the proposed M-DNA structural model. Firstly, experiments that demonstrated ionizing or ultraviolet radiation induced interstrand crosslinking in M-DNA are consistent with the hypothesis that M-DNA maintains a double-helical structure in which guanine binds with cytosine and adenine with thymine. These experiments also provide new insights into the effects of radiation on DNA in the presence of various metal ions at physiological and alkaline pHs. Secondly, a titration experiment was performed in which it was shown that for each metal cation that binds to M-DNA, approximately one proton is released. This result is consistent with the hypothesis that imino protons are released during M-DNA formation. Thirdly, crystals of the sequence d (GGCGCC) complexed with cobalt, nickel and zinc were grown. They did not grow in conditions above pH 8.1 and thus do not provide a solid state structural model for M-DNA. Interestingly, X-ray diffraction experiments revealed metal binding only to terminal N (7) positions of guanine residues with coordinated water molecules interacting with neighboring guanine residues affecting the propeller twist. Though the crystals had a high solvent content, it is interesting that the few interactions involving the metal cations were sufficient to stabilize the crystal lattice.
Pagination: 187p.
Appears in Departments:Department of Biotechnology

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07_chapter 1.pdfAttached File437.93 kBAdobe PDFView/Open
08_ chapter 2.pdf474.79 kBAdobe PDFView/Open
08_chapter 3.pdf363.94 kBAdobe PDFView/Open
09_chapter 4.pdf1.08 MBAdobe PDFView/Open
10_ chapter 5.pdf191.93 kBAdobe PDFView/Open
11_summary.pdf88.78 kBAdobe PDFView/Open
05_abstract.pdf83.64 kBAdobe PDFView/Open
04_acknowledgement.pdf119.67 kBAdobe PDFView/Open
02_certificate & declaration.pdf132.95 kBAdobe PDFView/Open
13_publication 1.pdf980.63 kBAdobe PDFView/Open
14_ publication 2.pdf121.62 kBAdobe PDFView/Open
03_contents.pdf109.62 kBAdobe PDFView/Open
06_list of tables & list of figures.pdf176.53 kBAdobe PDFView/Open
01_title.pdf24.92 kBAdobe PDFView/Open
12_references.pdf311.84 kBAdobe PDFView/Open

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