TY  - JOUR
AU  - Sarter, Mona
AU  - Niether, Doreen
AU  - König, Bernd
AU  - Lohstroh, Wiebke
AU  - Zamponi, Michaela
AU  - Jalarvo, Niina H.
AU  - Wiegand, Simone
AU  - Fitter, Jörg
AU  - Stadler, Andreas M.
TI  - Strong Adverse Contribution of Conformational Dynamics to Streptavidin-Biotin Binding
JO  - The journal of physical chemistry  / B
VL  - 124
IS  - 2
SN  - 1089-5647
CY  - Washington, DC
PB  - Soc.
M1  - FZJ-2019-05758
SP  - 324-335
PY  - 2020
AB  - 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.
LB  - PUB:(DE-HGF)16
C6  - pmid:31710813
UR  - <Go to ISI:>//WOS:000508468600003
DO  - DOI:10.1021/acs.jpcb.9b08467
UR  - https://juser.fz-juelich.de/record/866680
ER  -