Effects of crowding and environment on the evolution of conformational ensembles of the multi-stimuli-responsive intrinsically disordered protein, Rec1-resilin: a small-angle scattering investigation
No Thumbnail Available
Date
2016-06-09
Journal Title
Journal ISSN
Volume Title
Publisher
American Chemical Society
Abstract
In this study, we explore the overall structural ensembles and transitions of a biomimetic, multi-stimuli-responsive, intrinsically disordered protein (IDP), Rec1-resilin. The structural transition of Rec1-resilin with change in molecular crowding and environment is evaluated using small-angle neutron scattering and small-angle X-ray scattering. The quantitative analyses of the experimental scattering data using a combination of computational models allowed comprehensive description of the structural evolution, organization, and conformational ensembles of Rec1-resilin in response to the changes in concentration, pH, and temperature. Rec1-resilin in uncrowded solutions demonstrates the equilibrium intrinsic structure quality of an IDP with radius of gyration Rg ∼ 5 nm, and a scattering function for the triaxial ellipsoidal model best fit the experimental dataset. On crowding (increase in concentration >10 wt %), Rec1-resilin molecules exert intermolecular repulsive force of interaction, the Rg value reduces with a progressive increase in concentration, and molecular chains transform from a Gaussian coil to a fully swollen coil. It is also revealed that the structural organization of Rec1-resilin dynamically transforms from a rod (pH 2) to coil (pH 4.8) and to globular (pH 12) as a function of pH. The findings further support the temperature-triggered dual-phase-transition behavior of Rec1-resilin, exhibiting rod-shaped structural organization below the upper critical solution temperature (∼4 °C) and a large but compact structure above the lower critical solution temperature (∼75 °C). This work attempted to correlate unusual responsiveness of Rec1-resilin to the evolution of conformational ensembles. © 2016 American Chemical Society
Description
Keywords
Monomers, Peptides, Proteins, X-ray diffraction, Small angle scattering, Microstructure
Citation
Balu, R., Mata, J. P., Knott, R., Elvin, C. M., Hill, A. J., Choudhury, N. R., & Dutta, N. K. (2016). Effects of crowding and environment on the evolution of conformational ensembles of the multi-stimuli-responsive intrinsically disordered protein, Rec1-resilin: a small-angle scattering investigation. The Journal of Physical Chemistry B, 120(27), 6490-6503. doi:10.1021/acs.jpcb.6b02475