Photolyase: Its Damaged DNA Substrate and Amino Acid Radical Formation During Photorepair

dc.contributor.authorHurley, E. Kennethen
dc.contributor.committeechairKim, Sunyoungen
dc.contributor.committeememberPhillips, John B.en
dc.contributor.committeememberBevan, David R.en
dc.contributor.committeememberKennelly, Peter J.en
dc.contributor.departmentBiochemistryen
dc.date.accessioned2014-03-14T20:31:13Zen
dc.date.adate2005-02-03en
dc.date.available2014-03-14T20:31:13Zen
dc.date.issued2005-01-06en
dc.date.rdate2006-02-03en
dc.date.sdate2005-01-31en
dc.description.abstractUltraviolet light damages genomic material by inducing the formation of covalent bonds between adjacent pyrimidines. Cis-syn cyclobutane pyrimidine dimers (CPD)constitute the most abundant primary lesion in DNA. Photolyase, a light-activated enzyme, catalytically repairs these lesions. Although many steps in the photolyase-mediated repair process have been mapped, details of the mechanism remain cryptic. Difference FT-IR spectroscopy was employed to obtain new mechanistic information about photorepair. Purified oligonucleotides, containing a central diuracil, dithymidine, or cyclobutane thymidine dimer, were monitored using vibrational methods. Construction of difference infrared data between undamaged and damaged DNA permitted examination of nucleic acid changes upon formation of the CPD lesion; these experiments indicated that C=O and C-H frequencies can be used as markers for DNA damage. Furthermore, in purified photolyase containing isotopically-labeled aromatic amino acids, we observed that tryptophan residues in photolyase underwent structural changes during photorepair. These data indicate that electron transfer during DNA repair occurs through-bond, and that redox-active, aromatic residues form the pathway for electron transfer.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-01312005-145858en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-01312005-145858/en
dc.identifier.urihttp://hdl.handle.net/10919/31084en
dc.publisherVirginia Techen
dc.relation.haspartEKH_Thesis.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectamino acid radicalen
dc.subjectthymine dimeren
dc.subjectDNA repairen
dc.subjectphotolyaseen
dc.titlePhotolyase: Its Damaged DNA Substrate and Amino Acid Radical Formation During Photorepairen
dc.typeThesisen
thesis.degree.disciplineBiochemistryen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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