Transient Conformational Changes of Sensory Rhodopsin II Investigated by Vibrational Stark Effect Probes
| Autor: | Hendrik Mohrmann, Joachim Heberle, Víctor A. Lórenz-Fonfría, Ines Kube, Martin Engelhard |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Halobacterium Conformational change Protein Conformation Archaeal Proteins Static Electricity 010402 general chemistry 01 natural sciences 03 medical and health sciences symbols.namesake Protein structure Static electricity Spectroscopy Fourier Transform Infrared Materials Chemistry Sensory Rhodopsins Physical and Theoretical Chemistry skin and connective tissue diseases biology Chemistry Sensory rhodopsin II Hydrogen Bonding biology.organism_classification Transmembrane protein Recombinant Proteins 0104 chemical sciences Surfaces Coatings and Films Photoexcitation Crystallography 030104 developmental biology Stark effect Biophysics symbols sense organs |
| Zdroj: | The journal of physical chemistry. B. 120(19) |
| ISSN: | 1520-5207 |
| Popis: | Sensory rhodopsin II (SRII) is the primary light sensor in the photophobic reaction of the halobacterium Natronomonas pharaonis. Photoactivation of SRII results in a movement of helices F and G of this seven-helical transmembrane protein. This conformational change is conveyed to the transducer protein (HtrII). Global changes in the protein backbone have been monitored by IR difference spectroscopy by recording frequency shifts in the amide bands. Here we investigate local structural changes by judiciously inserting thiocyanides at different locations of SRII. These vibrational Stark probes absorb in a frequency range devoid of any protein vibrations and respond to local changes in the dielectric, electrostatics, and hydrogen bonding. As a proof of principle, we demonstrate the use of Stark probes to test the conformational changes occurring in SRII 12 ms after photoexcitation and later. Thus, a methodology is provided to trace local conformational changes in membrane proteins by a minimal invasive probe at the high temporal resolution inherent to IR spectroscopy. |
| Databáze: | OpenAIRE |
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