RT Journal Article T1 Simulating protein unfolding under pressure with a coarse-grained model A1 Perezzan, Ramiro A1 Rey Gayo, Antonio AB We describe and test a coarse-grained molecular model for the simulation of the effects of pressure on the folding/unfolding transition of proteins. The model is a structure-based one, which takes into account the desolvation barrier for the formation of the native contacts. The pressure is taken into account in a qualitative, mean field approach, acting on the parameters describing the native stabilizing interactions. The model has been tested by simulating the thermodynamic and structural behavior of protein GB1 with a parallel tempering Monte Carlo algorithm. At low effective pressures, the model reproduces the standard two-state thermal transition between the native and denatured states. However, at large pressures a new state appears. Its structural characteristics have been analyzed, showing that it corresponds to a swollen version of the native structure. This swollen state is at equilibrium with the native state at low temperatures, but gradually transforms into the thermally denatured state as temperature is increased. Therefore, our model predicts a downhill transition between the swollen and the denatured states. The analysis of the model permits us to obtain a phase diagram for the pressure-temperature behavior of the simulated system, which is compatible with the known elliptical shape of this diagram for real proteins. PB American Institute of Physics SN 0021-9606 YR 2012 FD 2012 LK https://hdl.handle.net/20.500.14352/42701 UL https://hdl.handle.net/20.500.14352/42701 LA eng NO Ministerio de Ciencia e InnovaciĆ³n (MICINN) NO Comunidad de Madrid DS Docta Complutense RD 6 abr 2025