Binding of calmodulin changes the calcineurin regulatory region to a less dynamic conformation
| Autor: | Junting Zhang, Ye Zheng, Hongbing Xu, Shaoning Yu, Cuiping Fu |
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| Rok vydání: | 2015 |
| Předmět: |
Models
Molecular Conformational change Calmodulin Phosphatase Gene Expression Plasma protein binding Biochemistry Protein Structure Secondary Structural Biology Spectroscopy Fourier Transform Infrared Escherichia coli Humans Cloning Molecular Binding site Molecular Biology Binding Sites biology Protein Stability Chemistry Calcineurin Active site Isothermal titration calorimetry General Medicine Recombinant Proteins Protein Structure Tertiary Dissociation constant Kinetics Crystallography biology.protein Biophysics Thermodynamics Calcium Protein Binding |
| Zdroj: | International Journal of Biological Macromolecules. 79:235-239 |
| ISSN: | 0141-8130 |
| Popis: | Calcineurin (CN) is a Ca(2+)/calmodulin (CaM) activated serine/threonine phosphatase, and its regulatory region (CNRR) plays a critical role in the coupling of Ca(2+) signals to cellular responses. Ca(2+)/CaM binds to the CNRR, resulting in a conformational change that removes an autoinhibitory domain (CN467-486) from the active site of the phosphatase and activates the enzyme. However, almost the entire regulatory region (CN374-521) is not visible in the electron density maps of reported structures. In this study, we produced separate CN fragments corresponding to the CNRR (CNRR381-521, CN residues 381-521) and determined the binding affinity of CNRR381-521 for Ca(2+)/CaM using isothermal titration calorimetry (ITC). The structural change in CNRR381-521 induced by Ca(2+)/CaM binding was also investigated by Fourier transform infrared spectroscopy (FT-IR). The results indicate that Ca(2+)/CaM binding to CNRR381-521 is an exothermic reaction with a dissociation constant of 2.0×10(-6) M. Binding of calmodulin changes the calcineurin regulatory region to a less dynamic conformation. |
| Databáze: | OpenAIRE |
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