Sekatskii, S. K.Favre, M.Dietler, G.Mikhailov, A. G.Klinov, D. V.Lukash, S. V.Deyev, S. M.2011-09-132011-09-132011-09-13201010.1002/jmr.1030https://infoscience.epfl.ch/handle/20.500.14299/70923WOS:000284022700011Results 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 0.75-0.85X10(-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. Copyright (C) 2010 John Wiley & Sons, Ltd.barnasebarstarligand-receptor interactionsforce spectroscopytext::journal::journal article::research article