Regular Article - Soft Matter
Electrostatics and hydrophobicity in the dynamics of intrinsically disordered proteins
Department of Chemical and Structural Biology, Weizmann Institute of Science, Herzl St. 234, 76100, Rehovot, Israel
2 Present Address: Department of Structural and Molecular Biology, University College London, Darwin Building, 107 Gower Street, WC1E 6BT, London, UK
Accepted: 20 November 2023
Published online: 21 December 2023
Internal friction is a major contribution to the dynamics of intrinsically disordered proteins (IDPs). Yet, the molecular origin of internal friction has so far been elusive. Here, we investigate whether attractive electrostatic interactions in IDPs modulate internal friction differently than the hydrophobic effect. To this end, we used nanosecond fluorescence correlation spectroscopy (nsFCS) and single-molecule Förster resonance energy transfer (FRET) to quantify the conformation and dynamics of the disordered DNA-binding domains Myc, Max and Mad at different salt concentrations. We find that internal friction effects are stronger when the chain is compacted by electrostatic attractions compared to the hydrophobic effect. Although the effect is moderate, the results show that the heteropolymeric nature of IDPs is reflected in their dynamics.
© The Author(s) 2023
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