Pressure-induced unfolding of 23kDa protein from spinach photosystem Ⅱ has been systematically investigated at various experimental conditions. Thermodynamic equilibrium studies indicate that the protein is very sensitive to pressure. At 20 ℃ and pH 5.5, 23kDa protein shows a reversible two-state unfolding transition under pressure with a midpoint near 160 Mpa, which is much lower than most natural proteins studied to date. The free energy……
