Journal Article

FZJ-2019-05758

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Strong Adverse Contribution of Conformational Dynamics to Streptavidin-Biotin Binding

Sarter, M.FZJ* ; Niether, D.FZJ* ; König, B.FZJ* ; Lohstroh, W. ; Zamponi, M.FZJ* ; Jalarvo, N. H.Extern* ; Wiegand, S.FZJ* ; Fitter, J. (Corresponding author)FZJ* ; Stadler, A. M. (Corresponding author)FZJ*

2020
Soc. Washington, DC

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Please use a persistent id in citations: http://hdl.handle.net/2128/23995  doi:10.1021/acs.jpcb.9b08467

Abstract: 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.

Keyword(s): Polymers, Soft Nano Particles and Proteins (1st) ; Soft Condensed Matter (2nd)

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Contributing Institute(s):

1. Molekulare Biophysik (ICS-5)
2. Weiche Materie (ICS-3)
3. Strukturbiochemie (ICS-6)
4. Neutronenstreuung (JCNS-1)
5. JCNS-SNS (JCNS-SNS)
6. Neutronenstreuung (ICS-1)
7. JCNS-FRM-II (JCNS-FRM-II)

Research Program(s):

1. 551 - Functional Macromolecules and Complexes (POF3-551) (POF3-551)

Experiment(s):

1. SPHERES: Backscattering spectrometer (NL6S)
2. TOFTOF: Cold neutron time-of-flight spectrometer (NL2au)

Appears in the scientific report 2020

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Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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