Abstract
The interactions of Mn2+ and Co2+ with glucose isomerases from three microbial sources have been studied using various direct physical methods. Co2+ was found to activate each enzyme, although the degree of activation varied significantly for enzymes from different organisms. EPR spectroscopy measurements revealed that dissimilarities in the coordination sphere of enzyme-bound Mn2+ accompanied the differences in enzyme activity. Variations in the EPR spectra of a nitroxide spin label coupled to two of the three isomerases, possibly near their active sites, were also observed. In no case was the EPR spectrum influenced by Co2+ addition, a result discordant with the hypothesis that Co2+ activates the enzyme by inducing a conformational change. The proximal biochemical environment of enzymebound Co2+ was also examined using EXAFS spectroscopy. This method showed that glucose causes notable changes in the ligand environment of the enzyme-bound metal, suggesting the formation of an enzyme-metal-substrate bridge complex. The significance of these results relative to possible reaction mechanisms is discussed.
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Crueger, W.; Crueger, A. 1984: Biotechnology: A textbook of industrial microbiology. Madison: Science Tech., Inc.
Bucke, C. 1983: There is more to sweeteners than sweetness. Trends Biotechnol. 1, 67–69
Antrim, R. L.; Colilla, W.; Schnyder, B. J. 1979: Glucose isomerase production of high-fructose syrups. In: Wingard, Jr., L. B.; Katchalski-Katzir, E.; Goldstein, L. (Eds.): Applied Biochemistry and Bioengineering, vol. 2, Enzyme Technology, pp. 97–155. New York: Academic Press
Danno, G. 1971: Studies on D-glucose-isomerizing enzyme from Bacillus coagulans, Strain HN-68. Agric. Biol. Chem. 35, 997–1006
Young, J. M; Schray, K. J.; Mildvan, A. S. 1975: Proton magnetic relaxation studies of the interaction of D-xylose and xylitol with D-xylose isomerase. J. Biol. Chem. 250, 9021–9027
Mildvan, A. S.; Rose, I. A. 1969: NMR and stereochemical studies of the mechanism of D-xylose isomerase. Federation Proc. 28, 534
Mildvan, A. S. 1970: Metals in enzyme catalysis. In: Boyer, P. D. (Ed.): The enzymes, Student Ed., vol. 2, p. 511. New York: Academic Press
Reed, G. H.; Markham, G. D. 1984: EPR of Mn(II) complexes with enzymes and other proteins. In: Berliner, L. J.; Reuben, J. (Eds.): Biological Magnetic Resonance, vol. 6, pp. 73–142. New York: Plenum Press
Bailey, J. E.; Clark, D. S.: EPR studies of immobilized chymotrypsin. In: Mosbach, K. (Ed.): Methods in enzymology, in press. New York: Academic Press
Morrisett, J. D. 1976: The use of spin labels for studying the structure and function of enzymes. In: Berliner, L. J. (Ed.): Spin labeling: theory and applications, pp. 273–338. New York: Academic Press
Clark, D. S.; Bailey, J. E. 1983: Structure-function relationships in immobilized chymotrypsin catalysis. Biotechnol. Bioeng. 25, 1027–1047
Clark, D. S.; Bailey, J. E. 1984: Characterization of heterogeneous immobilized enzyme subpopulations using EPR spectroscopy. Biotechnol. Bioeng. 26, 231–238
Clark, D. S.; Bailey, J. E. 1984: Deactivation kinetics of immobilized α-chymotrypsin subpopulations. Biotechnol. Bioeng. 26, 1090–1097
Hoschke, A.; Balogh, K.; Laszlo, E.; Hollo, E. 1984: Determination of functional groups in glucose isomerase. Starch/Starke. 36, 26–30
Cramer, S. P. 1979: Structure determination by X-ray absorptin spectroscopy — including applications from the study of molybdenum proteins. In: Castellani, A.; Quercia, I. F. (Eds.): Synchrotron radiation applied to biophysical research, pp. 291–322. New York: Plenum Press
Lytle, F. W.; Sagers, D. E.; Stern, E. A. 1982: The history and modern practice of EXAFS spectroscopy. In: Bonnelle, C.; Mande, C. (Eds.): Advances in X-ray spectroscopy, pp. 267–286. New York: Pergamon Press
Bock, K.; Wiebe, L. 1983: Report on the enzyme catalyzed conversion of D-glucose into a mixture of D-glucose and D-fructose. Acta Chem. Scand. Ser. B37, 101–108
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Branner, S., Marg, G., Ozer, R. et al. EPR and EXAFS studies of glucose isomerase activation by divalent metals. Bioprocess Engineering 1, 71–77 (1986). https://doi.org/10.1007/BF00387498
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DOI: https://doi.org/10.1007/BF00387498