Tridodecylamine and its hydrochloride salt: an organo-soluble buffer for subtilisin Carlsberg in non-polar organic solvents

Mixtures of commercially available tridodecylamine and its hydrochloride dissolved in hexane or toluene have been used as acid-base buffers for a suspended immobilised enzyme. The activity of subtilisin Carlsberg increases with the proportion of free amine, to a similar extent in both solvents. This indicates that the buffer fixes the ionisation state of the enzyme in the range appropriate for catalytic activity.