Reverse micellar enzymology

Reversed micellar enzymology has been extensively studied [114-116]. However, neither a large-scale operation, nor the enzyme and product recoveries for its practical application have been successfully carried out. The reversed micelle is a favorable reaction field for... 

Reversed micellar enzymology has been studied by many researchers [1, 2]. The conversion of apolar compounds by enzymes entrapped in aqueous cores of reversed micelles has drawn the most attention. Reversed micellar enzymology requires not only a large-scale operation, but also enzyme and product recoveries for its practical application. There is still a lack of understanding of many aspects of enzyme behavior in reversed micelles. 

The most important properties of reverse micellar systems, which are of significance for enzyme activity and stability, will be described in this section. Some of the properties are illustrated schematically and reduced to the major aspects of their influence in enzymology. 

Micellar enzymology which employs microheterogeneous surfactant-organic solvent-water systems as reaction media prove to be exceptionally technological and prospective in application. Therefore, it seems necessary once more to draw attention to the properties of reverse micelles. 

Proteases, when solubilized in the aqueous core of reverse micelles, can catalyze the hydrolysis of various small model peptides. In most of the cases, the substrates are partitioned between the micelles and the external solvent while the hydrolytic reaction is taking place within the dispersed aqueous domains. Since the beginning of micellar enzymology, a-chymotrypsin and trypsin have been extensively studied in different reverse micellar systems, employing various model peptides as substrates. In almost all cases the reactions followed Michaelis-Menten kinetics. 

As mentioned above, the catalytic activity of an enzyme is determined by its conformation in reverse micelles, so the characterization of the enzyme conformation is an important aspect of the somicellar enzymology. Infrared spectroscopy is a powerful technique for structural characterization [76-78]. For a protein hosted in reverse micelles, the spectral features of the protein are always interfered by the IR absorption bands of the medium in addition to the congestion in their IR spectra. Fortunately, there is a transparent window in the 2500-2200 cm region. Incorporation of a vibrational probe with IR absorption frequencies in this region into proteins represents a promising strategy for the study of the conformation of a protein in a reverse micelle. Huang et ul. [79] incorporated a 4-cyanobenzyl... 

Part III deals with micellar catalysis, enzymology, and photochemical reactions in reversed micelles. 

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