{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/97425"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/97425","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Identifying the mechanism of second proton release from the bc1 complex Qo-site","abstract":"The cytochrome bc1 complex and its family members play a central role in biological energy transduction across all domains of life, oxidizing QH2 in a bifurcated reaction which generates a proton-motive force used for ATP synthesis. It is widely accepted to operate according to a modified Q-cycle, but there is still debate over some aspects of the mechanism. We used the pH-sensitive dye neutral red to study the release of protons from the bc1 complex, with specific focus of the mechanism for release of the second proton from the Qo-site. Partial processes for the proton release could be isolated through use of different inhibitors, and correlated with electron transfers through the complex. We tested mutations at residues R94, N279, and Y147 in the b subunit of the complex, which are thought to interact with the water chain which provides a pathway for release of the second proton. Mutants R94A, N279F, and Y147T showed a significant decrease in proton release for a second turnover compared to the first, an indicator that the proton from the first turnover had difficulty leaving the complex. The latter two mutants also showed an intriguing difference in kinetics for the proton release and electron transfers for the first turnover.","abstract_html":"The cytochrome bc1 complex and its family members play a central role in biological energy transduction across all domains of life, oxidizing QH2 in a bifurcated reaction which generates a proton-motive force used for ATP synthesis. It is widely accepted to operate according to a modified Q-cycle, but there is still debate over some aspects of the mechanism. We used the pH-sensitive dye neutral red to study the release of protons from the bc1 complex, with specific focus of the mechanism for release of the second proton from the Qo-site. Partial processes for the proton release could be isolated through use of different inhibitors, and correlated with electron transfers through the complex. We tested mutations at residues R94, N279, and Y147 in the b subunit of the complex, which are thought to interact with the water chain which provides a pathway for release of the second proton. Mutants R94A, N279F, and Y147T showed a significant decrease in proton release for a second turnover compared to the first, an indicator that the proton from the first turnover had difficulty leaving the complex. The latter two mutants also showed an intriguing difference in kinetics for the proton release and electron transfers for the first turnover.","abstract_has_math":false,"creators":["Wilson, Charles Alexander"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Biophysics & Computnl Biology","degree_department":null,"school":null,"contributors":["Crofts, Antony","Aksimentiev, Oleksii","Gennis, Robert","Gruebele, Martin"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-08-10T19:15:40Z","date_published":"2017-08-10T19:15:40Z","updated_at":"2026-07-22T22:24:34Z","subjects":["Bc1 complex","Rhodobacter sphaeroides"],"languages":["en"],"rights":["Copyright 2017 Charles Wilson"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/97425","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Crofts, Antony","Aksimentiev, Oleksii","Gennis, Robert","Gruebele, Martin"]},{"key":"dc:creator","label":"Author","values":["Wilson, Charles Alexander"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-08-10T19:15:40Z","2017-04-21","2017-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biophysics & Computnl Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Bc1 complex","Rhodobacter sphaeroides"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2017 Charles Wilson"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/97425"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The cytochrome bc1 complex and its family members play a central role in biological energy transduction across all domains of life, oxidizing QH2 in a bifurcated reaction which generates a proton-motive force used for ATP synthesis. It is widely accepted to operate according to a modified Q-cycle, but there is still debate over some aspects of the mechanism. We used the pH-sensitive dye neutral red to study the release of protons from the bc1 complex, with specific focus of the mechanism for release of the second proton from the Qo-site. Partial processes for the proton release could be isolated through use of different inhibitors, and correlated with electron transfers through the complex. We tested mutations at residues R94, N279, and Y147 in the b subunit of the complex, which are thought to interact with the water chain which provides a pathway for release of the second proton. Mutants R94A, N279F, and Y147T showed a significant decrease in proton release for a second turnover compared to the first, an indicator that the proton from the first turnover had difficulty leaving the complex. The latter two mutants also showed an intriguing difference in kinetics for the proton release and electron transfers for the first turnover.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo terms","The student, Charles Wilson, accepted the attached license on 2017-04-20 at 17:00.","The student, Charles Wilson, submitted this Dissertation for approval on 2017-04-20 at 17:10.","This Dissertation was approved for publication on 2017-04-21 at 14:54.","DSpace SAF Submission Ingestion Package generated from Vireo submission #10943 on 2017-08-10 at 13:43:35","Made available in DSpace on 2017-08-10T19:15:40Z (GMT). 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It is widely accepted to operate according to a modified Q-cycle, but there is still debate over some aspects of the mechanism. We used the pH-sensitive dye neutral red to study the release of protons from the bc1 complex, with specific focus of the mechanism for release of the second proton from the Qo-site. Partial processes for the proton release could be isolated through use of different inhibitors, and correlated with electron transfers through the complex. We tested mutations at residues R94, N279, and Y147 in the b subunit of the complex, which are thought to interact with the water chain which provides a pathway for release of the second proton. Mutants R94A, N279F, and Y147T showed a significant decrease in proton release for a second turnover compared to the first, an indicator that the proton from the first turnover had difficulty leaving the complex. The latter two mutants also showed an intriguing difference in kinetics for the proton release and electron transfers for the first turnover.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo terms","The student, Charles Wilson, accepted the attached license on 2017-04-20 at 17:00.","The student, Charles Wilson, submitted this Dissertation for approval on 2017-04-20 at 17:10.","This Dissertation was approved for publication on 2017-04-21 at 14:54.","DSpace SAF Submission Ingestion Package generated from Vireo submission #10943 on 2017-08-10 at 13:43:35","Made available in DSpace on 2017-08-10T19:15:40Z (GMT). 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