Effect of thermodynamic water activity on protease-catalyzed peptide synthesis in mainly organic media

The role of water in mainly organic reaction mixtures for biocatalysis is best analysed in terms of the thermodynamic water activity. This determines water mass action effects on the equilibria of protease-catalysed peptide or ester synthesis. It can also be useful to predict the amount of water bound by the enzyme, and hence its catalytic activity, as other factors are changed.