Characterization of Enzymes in Reverse Micelles

Biocatalysis in organic solvents is of industrial importance for processes that operate in low-water conditions; however, enzymes have low activity and tend to denature rapidly in such environments. As a result, biocatalysis research has focused around the introduction of reverse micelles into the organic solvent to act as a host for enzymes. This study investigates the porcine enzyme malate dehydrogenase in a quaternary reverse micellular system containing cetylammonium bromide (CTAB), n-butanol, cyclohexane, and water. The research examined the size of the reverse micellular microenvironments as determined by dynamic light scattering. Experiments investigated the effects of salt concentration and the salt type on the size of the reverse micelles. Trials were also completed with the enzyme present. It was demonstrated that the salt concentration has an effect on micelle size; whereas the type of salts tested had residual effects. The introduction of enzyme into the reverse micellular systems did not cause a change in micelle size. Future work will explore the effect of different salts (cation/anion pairs) on the enzyme stability and activity.