Biochemical and biophysical analysis of the GTPase activating proteins of the small guanine nucleotide binding protein Rap1 and RheB
- This work covers biochemical characterization of GAP activation of the small GNBPs, Rap1 and RheB, which was achieved by a combination of techniques like infrared spectroscopy, mutational analysis and stopped flow kinetics. It was shown that RapGAP catalyzed reaction involves an additional intermediate GTP state, the chemical cleavage reaction is reversible and P\(_{i}\) release is rate limiting. The most important feature in GAP catalyzed reaction is a shift of negative charge towards the non-bridging oxygen of the \(\beta\) phosphate of GTP, which is more pronounced than Ras\(\cdot\)RasGAP system. A carboxyamide intermediate vibration was observed which in an independent study, turned out to be the catalytic asparagine residue of the GAP. RapGAP can down regulate mutations of position 61 and 12 of Rap and BeF\(_{3}\)\(^{-}\) is a better transition state mimic than AlF\(_{x}\), which indicates a dissociative mechanism. Also the \(\textit {in vitro}\) GAP activity of tuberin, a homolog could be demonstrated.
Download full text files
Additional Services
| Author: | Partha Pratim ChakrabartiGND |
|---|---|
| URN: | urn:nbn:de:hbz:294-13678 |
| Referee: | Alfred WittinghoferGND, Klaus GerwertORCiDGND, Rolf HeumannORCiDGND |
| Document Type: | Doctoral Thesis |
| Language: | English |
| Date of Publication (online): | 2005/07/26 |
| Date of first Publication: | 2005/07/26 |
| Publishing Institution: | Ruhr-Universität Bochum, Universitätsbibliothek |
| Granting Institution: | Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie |
| Date of final exam: | 2005/06/27 |
| Creating Corporation: | Fakultät für Chemie und Biochemie |
| GND-Keyword: | Tumorsuppressor-Gen; FT-IR-Spektroskopie; Kinetik; Guanosintriphosphatasen; Reversibilität |
| Institutes/Facilities: | Lehrstuhl für Biophysik |
| Max-Planck-Institut für molekulare Physiologie, Dortmund, Abteilung "Strukturelle Biologie" | |
| Dewey Decimal Classification: | Naturwissenschaften und Mathematik / Biowissenschaften, Biologie, Biochemie |
| faculties: | Fakultät für Chemie und Biochemie |
| Licence (German): |  Keine Creative Commons Lizenz - es gelten der Veröffentlichungsvertrag und das deutsche Urheberrecht |
