Multilevel Modeling To Understand The Folding Hysteresis Of GFP

The green fluorescent protein (GFP) is known to show hysteresis during folding. Experiments indicate that this hysteresis occurs due to the cooperative behavior of the chromophore and a few prolines which occur at the edge of the GFP barrel near the chromophore containing helix. Even one-bead-per-residue (C-alpha) structure-based (Go) simulations of GFP contain signatures of structural frustration near the proline regions. We explore the role of this frustration and the cooperativity of the prolines and the chromophore further by performing detailed simulations of GFP.