Conformational Changes in Calcium-Sensor Proteins under Molecular Crowding Conditions
| Autor: | Petra Behnen, Daniele Dell'Orco, Valerio Marino, Stefan Sulmann, Karl-Wilhelm Koch |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Conformational change
Light Calmodulin Biosensing Techniques Catalysis Troponin C Intracellular Calcium-Sensing Proteins Protein structure Dynamic light scattering Point Mutation Scattering Radiation Surface plasmon resonance conformational change biology Chemistry Protein dynamics Organic Chemistry dynamic light scattering General Chemistry Guanylate Cyclase-Activating Proteins Protein Structure Tertiary calcium sensor surface plasmon resonance Crystallography biology.protein Biophysics Calcium Protein folding Protein Binding |
| Popis: | Fundamental components of signaling pathways are switch modes in key proteins that control start, duration, and ending of diverse signal transduction events. A large group of switch proteins are Ca(2+) sensors, which undergo conformational changes in response to oscillating intracellular Ca(2+) concentrations. Here we use dynamic light scattering and a recently developed approach based on surface plasmon resonance to compare the protein dynamics of a diverse set of prototypical Ca(2+)-binding proteins including calmodulin, troponin C, recoverin, and guanylate cyclase-activating protein. Surface plasmon resonance biosensor technology allows monitoring conformational changes under molecular crowding conditions, yielding for each Ca(2+)-sensor protein a fingerprint profile that reflects different hydrodynamic properties under changing Ca(2+) conditions and is extremely sensitive to even fine alterations induced by point mutations. We see, for example, a correlation between surface plasmon resonance, dynamic light scattering, and size-exclusion chromatography data. Thus, changes in protein conformation correlate not only with the hydrodynamic size, but also with a rearrangement of the protein hydration shell and a change of the dielectric constant of water or of the protein-water interface. Our study provides insight into how rather small signaling proteins that have very similar three-dimensional folding patterns differ in their Ca(2+)-occupied functional state under crowding conditions. |
| Databáze: | OpenAIRE |
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