B. S. (Chemistry), Clarkson College of Technology, 1968; Ph.D.(Chemistry), University of Rochester, 1971, with L. E. Friedrich Uni-Royal Fellow, University of Rochester, 1969-71 National Institutes of Health, Postdoctoral Fellow, Columbia University, 1973-75 Alfred P. Sloan Fellow, 1977 Fellow, Center for Advanced Study, 1979 Dreyfus Teacher-Scholar Award, 1979 John Simon Guggenheim Fellowship, 1985 Mead Imaging Presidents Award, 1987 Paul Flory - IBM Fellowship, 1990 American Chemical Society A. C. Cope Scholar Award, 1993 Fellow – American Association Advancement of Science, 2002 American Chemical Society Herty Medal, 2006 Member, ACS Governing Board for Publications, Provost and Executive Vice President, Georgia Institute of Technology (2006-2010), Interim President, Georgia Institute of Technology (2008-2009), Dean, College of Sciences, Georgia Institute of Technology (1994-2006)
I am interested in damage to bases of DNA and RNA. The loss of an electron (oxidation) of duplex DNA results in the formation of a nucleobase radical cation (electron “hole”) that is subsequently consumed in chemical reactions that often lead to mutations. We have found that nucleobase damage need not occur at the site of the initial oxidation. Radical cations in DNA can migrate long distances (hundreds of Å) by a reversible hopping process before being trapped irreversibly by reaction with H2O and O2. A defining characteristic of this process is the preferential reaction at guanine. We showed that the reactions of nucleobase radical cations in DNA are determined by the specific sequence of bases that comprise the oligonucleotides. In particular, we observe that under certain circumstances oxidative reactions occurs at thymines despite the fact that it has a high oxidation potential. The consequences and mechanism of this reaction are under active investigation.