Related Experiment Video
Updated: Jul 3, 2026

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
Published on: January 16, 2016
Solvent effects on the catalytic activity of subtilisin suspended in compressed gases
I B de Carvalho1, T C de Sampaio, S Barreiros
1Instituto de Tecnológia Química e Biológica, Universidade Nova de Lisboa, R. da Quinta Grande, 6, Apt. 127, 2780 Oeiras, Portugal.
Abstract:
We studied a model transesterification reaction catalyzed by subtilisin Carlsberg suspended in carbon dioxide, propane, and mixtures of these solvents under pressure. To account for solvent effects due to differences in water partitioning between the enzyme and the bulk solvents, we measured water sorption isotherms for the enzyme in each solvent. We measured catalytic activity as a function of enzyme hydration and obtained bell-shaped curves with maxima at the same enzyme hydration (12%) in all the solvents. However, the activity maxima were different in all media, being much higher in propane than in either CO(2) or the mixtures with 50 and 10% CO(2). Considerations based on the solvation ability of the solvents did not offer an explanation for the differences in catalytic activity observed. Our results suggest that CO(2) has a direct adverse effect on the catalytic activity of subtilisin. (c) 1996 John Wiley & Sons, Inc.
Related Concept Videos
Physical Properties Affecting Solubility
As for any solution, the solubility of a gas in a liquid is affected by the attractive intermolecular forces between solute and solvent species. Unlike solid and liquid solutes, however, there is no solute-solute intermolecular attraction to overcome when a gaseous solute dissolves in a liquid solvent since the atoms or molecules comprising a gas are far separated and experience negligible interactions. Consequently, solute-solvent interactions are the sole...
Solubility
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules, atoms, and/or ions)...
Gas Solubility
Catalysis
Catalysis
Solvating Effects

