Dependence of DNA-protein cross-linking on DNA sequence

CHED 900

Julianna Scala, juliscal@msmc.la.edu1, Graciela Gonzalez1, Sherry Burton1, Christine Norashkharyan1, Jessica Palma, jesspalm@msmc.la.edu1, Amanda Madison1, and Eric D. A. Stemp2. (1) Mount St. Mary's College, 12001 Chalon Road, Los Angeles, CA 90049, (2) Department of Physical Sciences and Mathematics, Mount St. Mary's College, 12001 Chalon Road, Los Angeles, CA 90049
DNA sequences with GG or GGG sites in DNA are easily oxidized. To determine if a susceptibility to oxidative damage results in a corresponding vulnerability to DNA-protein cross-linking, we synthesized 20-mer oligonucleotide duplexes containing 5'-GC-3', 5'-GGC-3', and 5'-GGG-3' target sites. After inducing cross-links via flash-quench, covalent adducts were detected using a gel shift assay. The amount of DNA-protein cross-linking was found to decrease in the order: GCG> GGC> GGG. From transient absorption measurements, the yield of the long-lived G radical was found to be larger for the GGG sequence than for the GCG sequence, consistent with the higher reactivity expected for the isolated G sites.
 

Undergraduate Research Poster Session: Biochemistry
2:00 PM-4:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Division of Chemical Education

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007