Abstract
Results of the single molecule force spectroscopy study of specific interactions between ribonuclease barnase and its inhibitor barstar are presented. Experimental data obtained for the force loading rate ranging 2-70 nN/s are well approximated by a single straight line, from which the dissociation barrier of the width of 0.12 nm and height of 0.75-0.85×10-19 J can be inferred. The measured value of specific interaction does not depend on the NaCl concentration. This apparently contradicts the well-known dependence of the binding energy of this pair on the salt concentration, but such a "contradiction" is explained by the insensitivity of the force spectroscopy data to the relatively long-range electrostatic interaction. The latter essentially contributes to the value of barnase-barstar binding energy revealed by biochemical measurements, and it is exactly this electrostatic interaction which is influenced by the salt concentration.
Original language | English |
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Pages (from-to) | 583-588 |
Number of pages | 6 |
Journal | Journal of Molecular Recognition |
Volume | 23 |
Issue number | 6 |
DOIs | |
Publication status | Published - Nov 2010 |
Externally published | Yes |
Keywords
- Barnase
- Barstar
- Force spectroscopy
- Ligand-receptor interactions
ASJC Scopus subject areas
- Molecular Biology
- Structural Biology