| Description: | [DBS Seminar] Dr. Kalyan Sundar Chakrabarti (Dept. of NMR-based Structural Biology, MPIBPC, Göttingen) -- Conformational selection in protein-protein interactions |
| Date: | Wednesday, Feb 08, 2017 |
| Time: | noon - 1 p.m. |
| Venue: | 110, Lecture Hall Complex |
| Details: | Molecular recognition plays a central role in biology, and protein dynamics has been acknowledged to be important in this process. However, It is highly debated whether conformational changes happen before ligand binding to produce a binding-compatible state (conformational selection) or are caused in response to ligand binding (induced fit). Proposals for both mechanisms in protein-protein recognition have been primarily based on structural arguments. However, the distinction between them is a question of the probabilities of going via these two opposing pathways. I will present a direct demonstration of exclusive conformational selection in protein/protein recognition by measuring flux for rhodopsin kinase binding to its regulator recoverin, an important molecular recognition in the vision system. I will discuss the combined use of nuclear magnetic resonance (NMR) spectroscopy, stopped-flow kinetics and isothermal calorimetry to show that protein dynamics in free recoverin limits the overall rate of binding. I will discuss the extension (and limitation) of this approach in other systems, namely in the binding of Ubiquitin conjugating enzyme (E2) and Ubiquitin-ligase (E3). |
| Calendar: | Seminar Calendar (entered by abhadra) |