The effects of osmotic and hydrostatic pressures on macromolecular systems

Estimating hydration changes upon biomolecular reactions from osmotic stress, high pressure, and preferential hydration experiments

“…Volumetric analysis is another method that estimates the number of water molecules involved in reaction by measuring the changes in partial molar volumes of biomolecules (18,19). Partial molar volumes are obtained from the change of equilibrium when hydrostatic pressures is applied, in contrast to OSA's ''volume of water'' determined by the application of osmotic pressure (19).…”

“…Partial molar volumes are obtained from the change of equilibrium when hydrostatic pressures is applied, in contrast to OSA's ''volume of water'' determined by the application of osmotic pressure (19). Partial molar volumes can be measured from high pressure experiments (19,20), as well as densimetry (18).…”

“…Partial molar volumes are obtained from the change of equilibrium when hydrostatic pressures is applied, in contrast to OSA's ''volume of water'' determined by the application of osmotic pressure (19). Partial molar volumes can be measured from high pressure experiments (19,20), as well as densimetry (18). The number of water molecules may be inferred by the use of a two-state model for water (21), or through the estimated water density increment in the vicinity of biomolecules (10,19).…”

“…Partial molar volumes can be measured from high pressure experiments (19,20), as well as densimetry (18). The number of water molecules may be inferred by the use of a two-state model for water (21), or through the estimated water density increment in the vicinity of biomolecules (10,19).…”

“…The number of waters estimated from OSA and from volumetric analyses is often inconsistent (10,18,19,22). For example, a 4-fold difference was seen in the equilibrium dissociation of human IFN-␥ (10) and up to a 3-fold difference in the camphor binding of cytochrome P-450 (19).…”