| Abstract: | Dissolution of α-chymotrypsin in nonpolar organic solvents can be achieved using hydrophobic ion pairing, whereby the polar counterions are replaced by a stoichiometric number of detergent molecules. Using Aerosol OT[AOT, sodium bis(2-octyl)sulfosuccinate], it is possible to partition significant amounts of the enzyme into alkanes and chlorocarbons. Apparent solubility in isooctane is greater than 1 mg/mL (80 μM). Necessary conditions for achieving effective partitioning of α-chymotrypsin into these solvents are described. Using CD spectroscopy, it can be shown that the AOT–α-chymotrypsin (CMT) complex retains its native secondary and tertiary structure when dissolved in alkanes, and that the globular structure is stable to more than 100°C. In contrast, α-chymotrypsin unfolds at 54°C in aqueous solution. The relative solubility of the AOT–CMT complex in a variety of alkanes and chlorocarbons is also reported. The native structure of α-chymotrypsin is maintained in carbon tetrachloride, but not in methylene chloride or chloroform. © 1995 John Wiley & Sons, Inc. |
