Dokument: Protein dynamics as studied by single molecule Förster resonance energy transfer
| Titel: | Protein dynamics as studied by single molecule Förster resonance energy transfer | |||||||
| Weiterer Titel: | Untersuchung von Proteindynamiken mit Hilfe von Einzelmolekül-Förster-Resonanzenergietransfer | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=35990 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20160226-091033-4 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Dr. Rodnin, Dmitro [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Seidel, Claus A. M. [Gutachter] Prof. Dr. Gohlke, Holger [Gutachter] | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 540 Chemie | |||||||
| Beschreibung: | The structure and dynamics of two proteins, phage T4 lysozyme (T4L) and initiation factor 3 (IF3) from E.coli, were studied utilizing advanced single molecule fluorescence spectroscopy methods. These two proteins are examples for different dynamic regimes which are induced by the structure of the linker between their sub-domains.
T4L consists of two subdomains which are connected by a long and structured alpha helical linker (helix C). T4L is a well-studied protein with over 500 structure deposited in the PDB database. In this work three conformations of T4L were identified using network of 24 fluorescently double labeled variants of T4L. A previously unknown state C3 of T4L was identified. Furthermore, the complete kinetic scheme of the T4L was solved for the functional cycle of the protein. Two modes of subdomain movement were found, one corresponding to the previously described hinge bending motion between the conformation C1 and C2, and second representing a previously unknown motion between conformations C2 and C3 which presumably leads to the release of the product. IF3 also consists of two subdomains, but these are linked by a long and predominantly unstructured linker. IF3 plays an important role during the initiation of protein synthesis at the ribosome by binding to the 30S ribosomal subunit and controlling the composition of the initiation complex (IC). In this work IF3 in solution was identified as highly flexible protein with at least eight distinct interconverting states and three relaxation rates ranging from nano- to milliseconds. Upon the binding of IF3 to the 30S ribosomal subunit the majority of the IF3 molecules adopt one of the two alternative static conformations depending on the nature of the mRNA, the start codon selection and the strength of the Shine-Dalgarno interactions. Using T4L as a model protein, its unfolding behavior was studied in unfolding conditions of acidic pH or urea. The unfolding pathways and the mechanism of denaturation by urea and by protonation of T4L were found to be significantly different for T4L. Furthermore, non-ionic surfactant Tween 20 was tested as it is used to prevent adsorption for unfolding experiments. A strong influence of Tween 20 on the folding landscape of the T4L was detected for both denaturing conditions. | |||||||
| Lizenz: |  Urheberrechtsschutz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Chemie » Physikalische Chemie und Elektrochemie | |||||||
| Dokument erstellt am: | 26.02.2016 | |||||||
| Dateien geändert am: | 26.02.2016 | |||||||
| Promotionsantrag am: | 27.07.2015 | |||||||
| Datum der Promotion: | 24.08.2015 |
