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Molecular Motions and Interactions in Aqueous Solutions of Thymosin-β4, Stabilin CTD and Their 1?:?1 Complex,Studied by 1H-NMR Spectroscopy |
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| Authors: | Dr M Bokor Dr Á Tantos A Mészáros B Jenei R Haminda P Tompa Prof K Tompa |
| Institution: | 1. Department of Experimental Solid State Physics Wigner Research Centre, Konkoly-Thege út 29-33., 1121 Budapest, Hungary;2. Research Group of Intrinsically Disordered Proteins, Institute of Enzymology, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117 Budapest, Hungary;3. Chemical Institute, Eötvös Lóránd University, Pázmány P. sétány 1?A, 1117 Budapest;4. Research Group of Intrinsically Disordered Proteins, Institute of Enzymology, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117 Budapest, Hungary
Peter Tompa Lab, VIB-VUB Center for Structural Biology, Pleinlaan 2, 1050 Brussels, Belgium |
| Abstract: | Wide-line 1H NMR measurements were extended and all results were interpreted in a thermodynamics-based new approach on aqueous solutions of thymosin-β4 (Tβ4), stabilin cytoplasmic domain (CTD), and their 1 : 1 complex. Energy distributions of potential barriers controlling the motion of protein-bound water molecules were determined. Heterogeneous and homogeneous regions were found in the protein-water interface. The measure of heterogeneity of this interface gives quantitative value for the portion of disordered parts in the protein. Ordered structural elements were found extending up to ～20 % of the individual whole proteins. About 40 % of the binding sites of free Tβ4 get involved in bonds holding the complex together. The complex has the most heterogeneous solvent accessible surface (SAS) in terms of protein-water interactions. The complex is more disordered than Tβ4 or stabilin CTD. The greater SAS area of the complex is interpreted as a clear sign of its open structure. |
| Keywords: | hydration NMR spectroscopy potential barrier protein complex protein-protein interactions |