Abstract
The chemical characterization of horse liver alcohol dehydrogenase solubilized in isooctane via reverse micelles formed by the anionic surfactant di (2-ethyl-hexyl) sodium sulfosuccinate (AOT) and water (0.6 to 4% v/v) is presented. The enzyme’s catalytic activity toward acetaldehyde reduction is markedly dependent upon w0 = [H2O]/[AOT], and upon the pH of the stock aqueous solution (pHst), from which the hydrocarbon enzyme solution is prepared. Kinetically, the micellar solution appears to follow a normal Michaelis-Menten behavior, with a turnover number which, under the optimal conditions (w0 = 42, pHst = 8.8), appears to be higher than in bulk water. The affinity between enzyme and NADH, as judged from direct binding studies (quenching of the protein fluorescence), is much reduced with respect to water if concentrations refer to the water pool of the micelles, and comparable to water if concentrations refer to the overall volume (hydrocarbon plus water pool). Also, the Km values are much higher if concentrations refer to the water pool. Ultraviolet absorption studies show that the aromatic chromophores are not significantly perturbed on going from a water solution to the micellar solution. The essentially aqueous environment of the protein in the reverse micelles is confirmed by fluoresence studies. Circular dichroism studies show that the enzyme’s conformation in the micelles is similar to that in water; however, under certain conditions, small but significant changes of the main chain folding seem to occur, which do not impair enzymatic activity. The spectroscopic properties of NADH in the hydrocarbon phase (fluorescence and circular dichroism) are also investigated. The potential of the LADH-NADH system for technical applications (oxidoreduction of lipophylic substrates) is discussed.
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References
Bränden, C.-J., Jörnvall, H., Eklund, H., andFurugren, B. (1975)In The Enzymes, 3rd. ed., Vol. XI,Boyer, P. D. (ed.), Academic, New York, pp. 103–90.
Sund, H., andTheorell, H. (1963)In The Enzymes, 2nd. ed., Vol. VII,Boyer, P. D. (ed.), Academic, New York, pp. 25–57.
Joppich-Kuhn, R., andLuisi, P. L. (1976) Eur. L Biochem. 83: 593–599.
Abdallah, M. A., Biellmann, J.-F., Wiget, P., Joppich-Kuhn, R., andLuisi, P. L. (1978) Eur. J. Biochem. 89: 397–405.
Jones, J. B. andBeck, J. F. (1976)In Techniques of Chemistry, Vol. 10, Wiley, New York, pp. 107–401.
Theorell, H., andYonetani, T. (1963) Biochem. Z. 338: 537–53.
Zulauf, M., andEicke, H. F. (1979) J. Phys. Chem. 83: 480–86.
Menger, F. M., andSaito, G. (1978) J. Am. Chem. Soc. 100: 4376–79.
Wolf, R., andLuisi, P. L. (1979) Biochem. Biophys. Res. Commun. 89; 209–217.
Menger, F. M., andYamada, K. (1979) J. Am. Chem. Soc. 101: 6731–34.
Smith, R., andLuisi, P. L., Helv. Chem. Acta, 1981, in press.
Oppenheimer, N. J., Arnold, L. J., andKaplan, N. O. (1971) Proc. Natl. Acad. Sci. U.S.A. 68: 3200–5.
Baici, A., Luisi, P. L., Olomucki, A., Doublet, M.-O. S andKlincak, J. (1974) Eur. J. Biochem. 46: 59–66.
Dalzeil, K. (1963) J. Biol. Chem. 238: 2850–58.
Baici, A., Luisi, P. L., andAttanasi, O. (1975/76) J. Mol. Catal. 1: 223–44.
Theorell, H., andWiner, A. D. (1959) Arch. Biochem. Biophys. 83: 291–308.
Theorell, H., andMcKinley-McKee, J. S. (1961) Acta Chem. Scand. 15: 1811–33.
Bonner, F. J., Wolf, R., andLuisi, P. L. (1980) J. Solid-Phase Biochem. 5: 255–268, this issue.
References
Methods for Determining Metal Ion Environments in Proteins. By Dennis W. Darnall and Ralph G. Wilkins. Elsevier North-Holland, New York, 1980, 324 pages, $29.50.
Natural Sulfur Compounds: Novel Biochemical and Structural Aspects. Edited by Doriano Cavallini, Gerald E. Gaull, and Vincenzo Zappia. Plenum Press, New York, 1980, 552 pages, $49.50.
Dehydrogenases Requiring Nicotinamide Coenzymes. Edited byJonathan Jeffery. Birkhauser Boston, Inc., 1980, 284 pages, $36.
Structure and Bonding, Volume 41: Molecular Structure and Sensory Physiology. Edited by Peter Hemmerich. Springer-Verlag, New York, 1980, 146 pages, $36.80.
Enzyme Engineering: Future Directions. Edited by Lemuel B. Wingard, Jr., Ilia V. Berezin, and Anatole A. Klyosov. Plenum Press, New York, 1980, 521 pages, S59.50.
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Meier, P., Luisi, P.L. Micellar solubilization of biopolymers in hydrocarbon solvents. ii. the case of horse liver alcohol dehydrogenase. Journal of Solid-Phase Biochemistry 5, 269–282 (1980). https://doi.org/10.1007/BF03000662
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DOI: https://doi.org/10.1007/BF03000662