Abstract
Proteins imparted with intrinsic disorder conduct a range of essential cellular functions. To better understand the folding and hydration properties of intrinsically disordered proteins (IDPs), we used osmotic stress to induce conformational changes in nuclear co-activator binding domain (NCBD) and activator for thyroid hormone and retinoid receptor (ACTR) separate from their mutual binding. Osmotic stress was applied by the addition of small and polymeric osmolytes, where we discovered that water contributions to NCBD folding always exceeded those for ACTR. Both NCBD and ACTR were found to gain α-helical structure with increasing osmotic stress, consistent with their folding upon NCBD/ACTR complex formation. Using small-angle neutron scattering (SANS), we further characterized NCBD structural changes with the osmolyte ethylene glycol. Here a large reduction in overall size initially occurred before substantial secondary structural change. By focusing on folding propensity, and linked hydration changes, we uncover new insights that may be important for how IDP folding contributes to binding.
Original language | English |
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Pages (from-to) | 3695-3701 |
Number of pages | 7 |
Journal | Molecular BioSystems |
Volume | 12 |
Issue number | 12 |
DOIs | |
State | Published - 2016 |
Funding
This research was supported by the U.S. Department of Energy, Office of Basic Energy Sciences through ORNL Laboratory Directed Research and Development grant 05246 (C.S.). A portion of this research was performed at Oak Ridge National Laboratory's Spallation Neutron Source, sponsored by the U.S. Department of Energy, Office of Basic Energy Sciences. We acknowledge laboratory support by the Center for Structural Molecular Biology, funded by the Office of Biological and Environmental Research of the U.S. Department of Energy