Conformation switching of single native proteins revealed by nanomechanical probing without a pulling force
| Autor: | Menno Willem Jose Prins, Fabiola A. Gutiérrez-Mejía, Christian P. Moerland, Leo J. van IJzendoorn |
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| Přispěvatelé: | Applied Physics and Science Education, Molecular Biosensing for Med. Diagnostics |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Protein domain
Myocardial Infarction Troponin C/chemistry 02 engineering and technology 010402 general chemistry Biomarkers/metabolism 01 natural sciences Motor protein Protein structure Protein Domains Calcium/chemistry Myosin Myocyte Molecule Humans General Materials Science Actin Rotational Brownian motion Myocardial Infarction/metabolism Myocardium/chemistry Chemistry Myocardium 021001 nanoscience & nanotechnology 0104 chemical sciences Biophysics Calcium Troponin C 0210 nano-technology Biomarkers |
| Zdroj: | Nanoscale, 11(42), 19933-19942. Royal Society of Chemistry |
| ISSN: | 2040-3364 |
| Popis: | Protein conformational changes are essential to biological function, and the heterogeneous nature of the corresponding protein states provokes an interest to measure conformational changes at the single molecule level. Here we demonstrate that conformational changes in single native proteins can be revealed by non-covalent antibody-targeting of specific domains within the protein, using nanomechanical probing without an applied pulling force. The protein of interest was captured between a particle and a substrate and three properties were quantified: the twist amplitude related to an applied torque, torsional compliance related to rotational Brownian motion, and translational Brownian displacement. Calcium-dependent conformation switching was studied in native human cardiac troponin, a heterotrimer protein complex that regulates the contraction and relaxation of heart muscle cells and is also a key biomarker for diagnosing myocardial infarction. The data reveal a change in mechanical properties upon conformation switching from the non-saturated to the calcium-saturated state, which in cardiomyocytes gives myosin motor proteins access to actin filaments. A clear increase was observed in the molecular stiffness for the calcium-saturated protein conformation. Using libraries of monoclonal antibodies, the nanomechanical probing of conformation by antibody targeting opens avenues for characterizing single native protein complexes for research as well as for diagnostic applications. |
| Databáze: | OpenAIRE |
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