Crowder-directed interactions and conformational dynamics in multistimuli-responsive intrinsically disordered...

Area of Science:

• Biophysics
• Structural Biology
• Protein Dynamics

Background:

• Intrinsically disordered proteins (IDPs) exhibit dynamic conformational ensembles.
• The impact of macromolecular crowding on IDP dynamics is not fully understood due to ultrafast motions.

Purpose of the Study:

• To investigate crowder-induced interactions and conformational dynamics of the intrinsically disordered protein Rec1-resilin.
• To elucidate how varying crowder properties affect IDP structure and behavior.

Main Methods:

• Spectroscopic, spectrofluorimetric, and small-angle neutron scattering (SANS) techniques were employed.
• Deuterium-labeled Rec1-resilin was biosynthesized for enhanced neutron contrast.
• Ab initio shape reconstruction was used to generate 3D conformational models.

Main Results:

• Rec1-resilin displayed crowder-specific extension and compaction in response to varying macromolecular crowding levels.
• The observed structural changes were dependent on crowder size, form, topology, and concentration.
• A novel extension-contraction model was developed to explain IDP behavior in crowded states.

Conclusions:

• Macromolecular crowding significantly impacts the conformational ensembles of IDPs like Rec1-resilin.
• The study provides a framework for understanding IDP structural dynamics in crowded biological environments.
• Findings offer new perspectives on protein behavior in cellular contexts.