{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/31084"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/31084","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Photolyase: Its Damaged DNA Substrate and Amino Acid Radical Formation During Photorepair","abstract":"Ultraviolet 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.","abstract_html":"Ultraviolet 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.","abstract_has_math":false,"creators":["Hurley, E. Kenneth"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Biochemistry","degree_department":"Biochemistry","school":null,"contributors":[],"advisors":[],"committee_chairs":["Kim, Sunyoung"],"committee_members":["Phillips, John B.","Bevan, David R.","Kennelly, Peter J."],"year":2005,"date_issued":"2005-01-06","date_published":"2005-01-06","updated_at":"2026-07-22T22:19:18Z","subjects":["amino acid radical","thymine dimer","DNA repair","photolyase"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-01312005-145858"],"render_values":[{"text":"etd-01312005-145858","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/31084","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Kim, Sunyoung"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Phillips, John B.","Bevan, David R.","Kennelly, Peter J."]},{"key":"dc:contributor.department","label":"Department","values":["Biochemistry"]},{"key":"dc:creator","label":"Author","values":["Hurley, E. 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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."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Photolyase: Its Damaged DNA Substrate and Amino Acid Radical Formation During Photorepair"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Kim, Sunyoung"],"dc:contributor.committeemember":["Phillips, John B.","Bevan, David R.","Kennelly, Peter J."],"dc:contributor.department":["Biochemistry"],"dc:creator":["Hurley, E. Kenneth"],"dc:date.accessioned":["2014-03-14T20:31:13Z"],"dc:date.available":["2014-03-14T20:31:13Z","2006-02-03"],"dc:date.issued":["2005-01-06"],"dc:description.abstract":["Ultraviolet 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."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-01312005-145858"],"dc:identifier.uri":["http://hdl.handle.net/10919/31084"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["amino acid radical","thymine dimer","DNA repair","photolyase"],"dc:title":["Photolyase: Its Damaged DNA Substrate and Amino Acid Radical Formation During Photorepair"],"dc:type":["Thesis"],"thesis:degree_discipline":["Biochemistry"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:18Z"}