Rates Of Enzymic Reactions In Predominantly Organic, Low Water Systems

Abstract

This article makes a quantitative assessment of the activity of enzymes in predominantly organic reaction mixtures of very low water content (and thermodynamic water activity significantly less than 1). This is done by attempting to relate reaction rates to those in systems of higher water content, although several factors make fair comparison difficult. However, it seems that rates with lipases in low water systems can sometimes be at least as high as when the same amount of enzyme catalyses the same reaction in a more traditional system. Rates are usually higher when the catalyst is dispersed on a support, rather than with simple dried particles of enzymes. Rates per unit weight of catalyst are rather similar, even when the amount of active enzyme varies widely, suggesting that physical factors may be limiting. Little data is available for enzymes other than lipases.