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.
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.
Future Industries Institute, University of South Australia , Mawson Lakes, SA 5095, Australia.
Rajkamal
R
Balu
Bragg Institute, ANSTO , Private Mail Bag, Kirrawee, NSW 2232, Australia.
Jitendra P
JP
Mata
Bragg Institute, ANSTO , Private Mail Bag, Kirrawee, NSW 2232, Australia.
Robert
R
Knott
CSIRO Agriculture, Level 6, Queensland Bioscience Precinct , St Lucia, QLD 4067, Australia.
Christopher M
CM
Elvin
CSIRO Manufacturing , Bayview Avenue, Clayton, VIC 3168, Australia.
Anita J
AJ
Hill
School of Chemical Engineering, The University of Adelaide , Adelaide, SA 5005, Australia.|Future Industries Institute, University of South Australia , Mawson Lakes, SA 5095, Australia.
Namita R
NR
Choudhury
School of Chemical Engineering, The University of Adelaide , Adelaide, SA 5005, Australia.|Future Industries Institute, University of South Australia , Mawson Lakes, SA 5095, Australia.
Naba K
NK
Dutta
D000067493:Dynamic Light Scattering; D006863:Hydrogen-Ion Concentration; D019476:Insect Proteins / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D053838:Scattering, Small Angle; D013696:Temperature; D014961:X-Ray Diffraction
D019476:Insect Proteins; C030951:resilin