961 resultados para Practices of the Self
Filtro por publicador
- JISC Information Environment Repository (1)
- Repository Napier (1)
- Aberdeen University (2)
- Abertay Research Collections - Abertay University’s repository (1)
- Aberystwyth University Repository - Reino Unido (3)
- Academic Archive On-line (Stockholm University; Sweden) (1)
- Academic Research Repository at Institute of Developing Economies (2)
- AMS Campus - Alm@DL - Università di Bologna (1)
- AMS Tesi di Dottorato - Alm@DL - Università di Bologna (2)
- Aquatic Commons (5)
- ArchiMeD - Elektronische Publikationen der Universität Mainz - Alemanha (4)
- Archive of European Integration (3)
- Archivo Digital para la Docencia y la Investigación - Repositorio Institucional de la Universidad del País Vasco (5)
- Aston University Research Archive (7)
- Biblioteca Digital | Sistema Integrado de Documentación | UNCuyo - UNCUYO. UNIVERSIDAD NACIONAL DE CUYO. (1)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (11)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP) (6)
- Biblioteca Digital de Teses e Dissertações Eletrônicas da UERJ (3)
- BORIS: Bern Open Repository and Information System - Berna - Suiça (80)
- Boston University Digital Common (3)
- Brock University, Canada (31)
- Bucknell University Digital Commons - Pensilvania - USA (2)
- Bulgarian Digital Mathematics Library at IMI-BAS (2)
- CaltechTHESIS (2)
- Cambridge University Engineering Department Publications Database (6)
- CentAUR: Central Archive University of Reading - UK (75)
- Central European University - Research Support Scheme (1)
- Chinese Academy of Sciences Institutional Repositories Grid Portal (50)
- Cochin University of Science & Technology (CUSAT), India (3)
- Collection Of Biostatistics Research Archive (1)
- Comissão Econômica para a América Latina e o Caribe (CEPAL) (6)
- CORA - Cork Open Research Archive - University College Cork - Ireland (5)
- Corvinus Research Archive - The institutional repository for the Corvinus University of Budapest (1)
- Dalarna University College Electronic Archive (3)
- Deakin Research Online - Australia (161)
- DI-fusion - The institutional repository of Université Libre de Bruxelles (2)
- Digital Archives@Colby (2)
- Digital Commons - Michigan Tech (1)
- Digital Commons @ DU | University of Denver Research (1)
- Digital Commons @ Winthrop University (1)
- Digital Commons at Florida International University (7)
- Digital Peer Publishing (2)
- Digital Repository at Iowa State University (2)
- DigitalCommons@The Texas Medical Center (9)
- DigitalCommons@University of Nebraska - Lincoln (1)
- DRUM (Digital Repository at the University of Maryland) (1)
- Duke University (3)
- eResearch Archive - Queensland Department of Agriculture; Fisheries and Forestry (7)
- Glasgow Theses Service (1)
- Greenwich Academic Literature Archive - UK (2)
- Helda - Digital Repository of University of Helsinki (9)
- Indian Institute of Science - Bangalore - Índia (22)
- Instituto Politécnico de Leiria (1)
- Instituto Politécnico do Porto, Portugal (1)
- Massachusetts Institute of Technology (3)
- Memoria Académica - FaHCE, UNLP - Argentina (3)
- Memorial University Research Repository (1)
- Ministerio de Cultura, Spain (9)
- National Center for Biotechnology Information - NCBI (7)
- Open University Netherlands (1)
- Portal de Revistas Científicas Complutenses - Espanha (4)
- Publishing Network for Geoscientific & Environmental Data (4)
- QSpace: Queen's University - Canada (1)
- QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast (79)
- Queensland University of Technology - ePrints Archive (172)
- ReCiL - Repositório Científico Lusófona - Grupo Lusófona, Portugal (1)
- Repositorio Académico de la Universidad Nacional de Costa Rica (1)
- Repositório Científico da Universidade de Évora - Portugal (1)
- Repositório digital da Fundação Getúlio Vargas - FGV (1)
- Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho" (32)
- Research Open Access Repository of the University of East London. (3)
- RUN (Repositório da Universidade Nova de Lisboa) - FCT (Faculdade de Cienecias e Technologia), Universidade Nova de Lisboa (UNL), Portugal (1)
- School of Medicine, Washington University, United States (6)
- Universidad de Alicante (1)
- Universidad del Rosario, Colombia (1)
- Universidad Politécnica de Madrid (20)
- Universidade de Lisboa - Repositório Aberto (1)
- Universidade dos Açores - Portugal (2)
- Universitat de Girona, Spain (4)
- Université de Lausanne, Switzerland (2)
- Université de Montréal, Canada (13)
- University of Connecticut - USA (1)
- University of Michigan (10)
- University of Queensland eSpace - Australia (7)
- WestminsterResearch - UK (3)
Resumo:
Ribozymes of hepatitis delta virus have been proposed to use an active-site cytosine as an acid-base catalyst in the self-cleavage reaction. In this study, we have examined the role of cytosine in more detail with the antigenomic ribozyme. Evidence that proton transfer in the rate-determining step involved cytosine 76 (C76) was obtained from examining cleavage activity of the wild-type and imidazole buffer-rescued C76-deleted (C76Δ) ribozymes in D2O and H2O. In both reactions, a similar kinetic isotope effect and shift in the apparent pKa indicate that the buffer is functionally substituting for the side chain in proton transfer. Proton inventory of the wild-type reaction supported a mechanism of a single proton transfer at the transition state. This proton transfer step was further characterized by exogenous base rescue of a C76Δ mutant with cytosine and imidazole analogues. For the imidazole analogues that rescued activity, the apparent pKa of the rescue reaction, measured under kcat/KM conditions, correlated with the pKa of the base. From these data a Brønsted coefficient (β) of 0.51 was determined for the base-rescued reaction of C76Δ. This value is consistent with that expected for proton transfer in the transition state. Together, these data provide strong support for a mechanism where an RNA side chain participates directly in general acid or general base catalysis of the wild-type ribozyme to facilitate RNA cleavage.