Solubilization of enzymes

The solubilization of enzymes and proteins in water-containing reversed micelles has attracted a great deal of interest for their selective separation, purification, and efficient refolding and for bioreactions involving a wide class of polar, apolar, and amphiphilic reactants and products [13,44,162-164]. 

In vitro enzymatic polymerizations have the potential for processes that are more regio-selective and stereoselective, proceed under more moderate conditions, and are more benign toward the environment than the traditional chemical processes. However, little of this potential has been realized. A major problem is that the reaction rates are slow compared to non-enzymatic processes. Enzymatic polymerizations are limited to moderate temperatures (often no higher than 50-75°C) because enzymes are denaturated and deactivated at higher temperatures. Also, the effective concentrations of enzymes in many systems are low because the enzymes are not soluble. Research efforts to address these factors include enzyme immobilization to increase enzyme stability and activity, solubilization of enzymes by association with a surfactant or covalent bonding with an appropriate compound, and genetic engineering of enzymes to tailor their catalytic activity to specific applications. 

Luisi, P. L. and Laane, C. (1986). Solubilization of enzymes in apolar solvents via reverse micelles. Trends Biotechnol., 4, 29-38. 

The Solubilization of Enzymes, Carbohydrates and Inorganic Colloids in Organic Solvents... 

Wolf, R. Luisi, P. L. "Micellar solubilization of enzymes in hydrocarbon solvents. Enzymatic activity and spectroscopic prop>erties of ribonuclease in N-octane" Biochem. and Biophys. Res. Comm. 1979, 89, 1, pp 209-217. 

A recent and exciting area of research is the solubilization of enzymes in nonaqueous solvents. One way solubilization is achieved is through noncovalent complexes of lipid (surfactant) and protein, to be referred to here as enzyme-lipid aggregates, or ELAs. Such complexes are reported to be highly active and stable. Moreover, the activity of ELAs can be significantly higher than free, suspended enzyme (in the absence or presence of surfactant), enzymes solubilized in aqueous-organic biphasic systems, or reverse micellar solutions, and can approach catalytic rates in... 

Akbar U, Aschenbrenner CD, Harper MR et al. (2007) Direct solubilization of enzyme aggregates with enhanced activity in nonaqueous media. Biotechnol Bioeng 96(6) 1030-1039 Albetghina L (2000) Protein engineering in industrial biotechnology. CRC Press, Boca Raton 376 pp. ISBN 9057024128... 

Formation of surfactant coated starch nanopartides The loading of surfactant stabilized reverse micelles with starch nanospheres was studied. The surfactant-solvent systems used were AOT (sodium di-2-ethylhexylsulfosuccinate)/isooctane, CTAB (cetyl trimethyl ammonium bromideVchloroform and TritonX-100 (polyoxyethylene(10) isooctylphenylether)/toluene. These surfactants were selected due to their use by others for the solubilization of enzymes in reversed micelles(26-28). To load the reverse micelles, a concentrated (0.2Sg/mL) aqueous solution of starch nanospheres was added to the different surfactant/solvent pairs. The percent incorporation of starch in the nanospheres was determined based on the amount of the starch nanopartides that could be added to the surfactant/solvent system prior to the formation of a cloudy phase separated mixture. 

Luisi, P.L., Magid, L. 1986. Solubilization of enzymes and nucleic acids in hydrocarbon micellar solutions. CRC Crit. Rev. Biochem. 20,409-474. 

Rairkar, M.E., Hayes, D.G., Harris, Z.J.M. 2007. Solubilization of enzymes in water-in-oU microemulsions and their rapid and efficient release through use of a pH-degradable smfactant. Biotechnol. Lett. 29, 761-111. 

Table 1. Methods of Solubilization of Enzymes from Membranes...

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