Description: Strong Adverse Contribution of Conformational Dynamics to Streptavidin-Biotin Binding

This title appears in the Scientific Report : 2020

Strong Adverse Contribution of Conformational Dynamics to Streptavidin-Biotin Binding

Molecular dynamics plays an important role for the biological function of proteins. For protein ligand interactions, changes of conformational entropy of protein and hydration layer are relevant for the binding process. Quasielastic neutron scattering (QENS) was used to investigate differences in pr...

Personal Name(s):	Sarter, Mona
	Niether, Doreen / König, Bernd / Lohstroh, Wiebke / Zamponi, Michaela / Jalarvo, Niina H. / Wiegand, Simone / Fitter, Jörg (Corresponding author) / Stadler, Andreas M. (Corresponding author)
Contributing Institute:	Strukturbiochemie; ICS-6 Weiche Materie; ICS-3 Molekulare Biophysik; ICS-5 JCNS-FRM-II; JCNS-FRM-II Neutronenstreuung; ICS-1 JCNS-SNS; JCNS-SNS Neutronenstreuung; JCNS-1
Published in:	The journal of physical chemistry / B, 124 (2020) 2, S. 324-335
Imprint:	Washington, DC Soc. 2020
PubMed ID:	31710813
DOI:	10.1021/acs.jpcb.9b08467
Document Type:	Journal Article
Research Program:	Functional Macromolecules and Complexes
Subject (ZB):	Soft Condensed Matter > 0 Polymers, Soft Nano Particles and Proteins > 0
Link:	Published on 2019-11-11. Available in OpenAccess from 2020-11-11. Restricted Restricted
	Publikationsportal JuSER

Please use the identifier: http://dx.doi.org/10.1021/acs.jpcb.9b08467 in citations.
Please use the identifier: http://hdl.handle.net/2128/23995 in citations.

Molecular dynamics plays an important role for the biological function of proteins. For protein ligand interactions, changes of conformational entropy of protein and hydration layer are relevant for the binding process. Quasielastic neutron scattering (QENS) was used to investigate differences in protein dynamics and conformational entropy of ligand-bound and ligand-free streptavidin. Protein dynamics were probed both on the fast picosecond time scale using neutron time-of-flight spectroscopy and on the slower nanosecond time scale using high-resolution neutron backscattering spectroscopy. We found the internal equilibrium motions of streptavidin and the corresponding mean square displacements (MSDs) to be greatly reduced upon biotin binding. On the basis of the observed MSDs, we calculated the difference of conformational entropy ΔSconf of the protein component between ligand-bound and ligand-free streptavidin. The rather large negative ΔSconf value (−2 kJ mol–1 K–1 on the nanosecond time scale) obtained for the streptavidin tetramer seems to be counterintuitive, given the exceptionally high affinity of streptavidin–biotin binding. Literature data on the total entropy change ΔS observed upon biotin binding to streptavidin, which includes contributions from both the protein and the hydration water, suggest partial compensation of the unfavorable ΔSconf by a large positive entropy gain of the surrounding hydration layer and water molecules that are displaced during ligand binding.