Electron-transfer processes have been implicated to be involved in DNA damage and repair. Yet, little is known about the mechanism(s) by which electrons migrate through nucleic acids. The following fundamental questions are addressed : (a) What is the role played by the stacked base-pairs in controlling the electronic properties of DNA? (b) How does the global structure of DNA influence the electronic coupling between a donor and an acceptor? (c) How do mutations and exogenous ligands influence the electronic properties of DNA? The specific aims of the research program are: (a) To develop a general method for the sequence-specific incorporation of metal complexes into DNA using automated DNA synthesizers; (b) To examine the structural and functional consequences of the modifications of nucleic acids with metal complexes; (c) To study the effect of the following parameters on energy- and electron-transfer processes in DNA: (i) distance between donor and acceptor (ii) conjugation between the heterocyclic bases and donors and acceptors, (iii) sequences, (iv) global conformation (v) presence of mismatches and abasic site, and (vi) presence of intercalating and non-intercalating antitumor agents. A general and modular approach for the sequence-specific incorporation of metal centers into DNA using solid-phase automated DNA synthesis is proposed. The method relies on the synthesis of metal-containing nucleosides and phosphoramidites. Various coordination complexes with a range of redox and photophysical characteristics can be incorporated into oligonucleotides of any sequence, length and modification position. The systematic investigation of the biophysical, photophysical and energy- and electron-transfer properties of the modified DNAs proposed will allow critical evaluation of the electronic properties of DNA. Understanding the ability of DNA to mediate energy- and electron- transfer over a long range will clarify the potential involvement of such processes in mutagenesis and carcinogenesis. Evaluating the mechanisms leading to the generation and migration of oxidative damage in duplex DNA will facilitate the development of novel approaches to anti-cancer therapy.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM058447-02
Application #
6151220
Study Section
Metallobiochemistry Study Section (BMT)
Program Officer
Preusch, Peter C
Project Start
1999-02-01
Project End
2003-01-31
Budget Start
2000-02-01
Budget End
2001-01-31
Support Year
2
Fiscal Year
2000
Total Cost
$192,287
Indirect Cost
Name
University of California San Diego
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
077758407
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Luedtke, Nathan W; Hwang, Judy S; Nava, Eileen et al. (2003) The DNA and RNA specificity of eilatin Ru(II) complexes as compared to eilatin and ethidium bromide. Nucleic Acids Res 31:5732-40
Luedtke, Nathan W; Hwang, Judy S; Glazer, Edith C et al. (2002) Eilatin Ru(II) complexes display anti-HIV activity and enantiomeric diversity in the binding of RNA. Chembiochem 3:766-71
Hurley, Dennis J; Tor, Yitzhak (2002) Ru(II) and Os(II) nucleosides and oligonucleotides: synthesis and properties. J Am Chem Soc 124:3749-62
Hurley, Dennis J; Tor, Yitzhak (2002) Donor/acceptor interactions in systematically modified Ru(II)-Os(II) oligonucleotides. J Am Chem Soc 124:13231-41
Weizman, Haim; Tor, Yitzhak (2002) Redox-active metal-containing nucleotides: synthesis, tunability, and enzymatic incorporation into DNA. J Am Chem Soc 124:1568-9
Glazer, Edith C; Tor, Yitzhak (2002) RuII complexes of ""large-surface"" ligands. Angew Chem Int Ed Engl 41:4022-6
Hurley, Dennis J; Seaman, Susan E; Mazura, Jan C et al. (2002) Fluorescent 1,10-phenanthroline-containing oligonucleotides distinguish between perfect and mismatched base pairing. Org Lett 4:2305-8
Weizman, H; Tor, Y (2001) 2,2'-Bipyridine ligandoside: a novel building block for modifying DNA with intra-duplex metal complexes. J Am Chem Soc 123:3375-6