Use of dinitrofluorobenzene to modify enzymes for enhanced solubilization and activity in organic solvents

Abstract

It is now known that many enzymes can function as biocatalysts in, or in contact with, various organic solvents (1-5). As a result, such enzymes can now be considered for many different applications not previously thought to be possible in organic solvents. Approaches taken with this type of biocatalytic system have included the use of immobilized enzymes (6), enzymes particulates (7), enzymes in micelles (8), or enzymes in an aqueous phase that is in contact with the organic phase (6). These are effective ways of using biocatalysts for some applications providing the reaction is carried out in the liquid phase. However, if the enzyme must interact with a solid substrate, such as coal in the organic phase, it is desirable for the enzyme to be present in the organic media in a soluble form, since direct molecular interactions are a requirement. Some enzymes have minimal solubility in polar organics, especially those that contain water (9). However, there is only a limited solubility of enzymes in nonhydrous, polar organic solvents, since proteinaceous molecules are primarily hydrophilic. It may be possible to modify enzymes chemically to increase hydrophobicity and, thus, increase organic solubilization while maintaining catalytic activity. Several methods have been studied to