Aggregation of non-polar solutes in water at different pressures and temperatures: the role of hydrophobic interaction

FERRARA, CG; CHARA OSVALDO; GRIGERA JOSÉ RAÚL

JOURNAL OF CHEMICAL PHYSICS

AMER INST PHYSICS

Lugar: New York; Año: 2012 vol. 137 p. 1 - 5

0021-9606

Due to the importance of the hydrophobic interaction in protein folding, we decided to study the effect of pressure and temperature on the phase transitions of non-polar solutes in water, and thereby their solubility, using molecular dynamics simulations. The main results are: (1) within a certain range, temperature induces the aggregation of Lennard-Jones particles in water; and (2) pressure induces disaggregation of the formed clusters. From the simulated data, a non-monotonic coexistence curve for the binary system was obtained, from which a critical point of Tc = 383 ± 9 K and pc = 937 ± 11 bar was determined. The results are in accordance with previous experimental evidence involving transitions of hydrocarbons in water mixtures, and protein unfolding.