DOI QR코드

DOI QR Code

A Novel Iron(III) Complex with a Tridentate Ligand as a Functional Model for Catechol Dioxygenases: Properties and Reactivity of [Fe(BBA)DBC]$ClO_4$


Abstract

[FeIII(BBA)DBC]ClO4 as a new functional model for catechol dioxygenases has been synthesized, where BBA is a bis(benzimidazolyl-2-methyl)amine and DBC is a 3,5-di-tert-butylcatecholate dianion.The BBA complex has a structuralfeature that iron cent er has a five-coordinate geometry similar to that of catechol dioxygenase-substrate complex.The BBA complex exhibits strong absorptionbands at 560 and 820 nm in CH3CN which are assigned to catecholate to Fe(III) charge transfer transitions. It also exhibits EPR signals at g = 9.3 and 4.3 which are typical values for the high-spin FeIII (S = 5/2) complex with rhombicsymmetry. Interestingly, the BBA complex reacts with O2 within an hour to afford intradiol cleavage (35%) and extradiol cleavage (60%) products. Surprisingly, a green color intermediate is observed during the oxygenation process of the BBA com-plex in CH3CN. This green intermediate shows a broad isotropic EPR signal at g = 2.0. Based on the variable temperature EPR study, this isotropic signalmight be originated from the [Fe(III)-peroxo-catecholate] species havinglow-spin FeIII center, not from the simple organic radical. Consequently,it allows O2 to bind to iron cen-ter forming the Fe(III)-superoxide species that converts to the Fe(III)-peroxide intermediate. These present data can lead us tosuggest that the oxygen activation mechanism take place for the oxidative cleavingcatechols of the five-coordinate model systems for catechol dioxygenases.

Keywords

References

  1. Ann. Rev. Microbiol. v.42 Reineke, W.;Knackmuss, M. J.
  2. Microbial Degradation of Organic Molecules Dekkar, M.;Gibson, D. T.(Ed.)
  3. J. Chem. Educ. v.62 Que, L., Jr.
  4. Iron Carriers and Iron Proteins Que, L., Jr.;Loehr, T. M.(Ed.)
  5. Chem. Rev. v.96 Dioxygen Activation by Enzymes with Mononuclear Iron Active Sites Que, L., Jr.;Ho, R. Y. N.
  6. Inorg. Chem. v.26 Kent, T. A.;Munck, E.;Pyrz, J. W.;Widom, J.;Que, L., Jr.
  7. Biochemistry v.19 Que, L., Jr.;Heistand, R. H., II;Mayer, R.;Roe, A. L.
  8. Biochemistry v.20 Que, L., Jr.;Epstein. R. M.
  9. J. Biol. Chem. v.259 Whittaker, J. W.;Lipscomb, J. D.
  10. J. Am. Chem. Soc. v.104 Felton, R. H.;Barrow, W. L.;May, S. W.;Sowell, A. L.;Goel, S.
  11. J. Am. Chem. Soc. v.109 Que, L., Jr.;Lauffer, R. B.;Lynch, J. B.;Murch, B. P.;Pyrz, J. W.
  12. J. Biol. Chem. v.256 Bull, C.;Ballou, D. P.;Otsuka, S.
  13. J. Biol. Chem. v.258 Walsh, T. A.;Ballou, D. P.;Mayer, R.;Que, L., Jr.
  14. Nature v.336 Ohlendorf, D. H.;Lipscomb, J. D.;Weber, P. C.
  15. J. Biol. Chem. v.259 Whittaker, J. W.;Lipscomb, J. D.;Kent, T. A.;Munck, E.;Orme-Johnson, N. R.;Orme-Johnson, W. H.
  16. J. Biol. Chem. v.264 Orville, A. M.;Lipscomb, J. D.
  17. Biochemistry v.29 True, A. E.;Orville, A. M.;Pearce, L. L.;Lipscomb, J. D.;Que, L., Jr.
  18. Biochemistry v.36 Orville, A. M.;Lipscomb, J. D.;Ohlendorf, D. H.
  19. J. Am. Chem. Soc. v.109 Que, L., Jr.;Kolanczyk, R. C.;White, L. S.
  20. J. Am. Chem. Soc. v.110 Cox, D. D.;Benkovic, S. J.;Bloom, L. M.;Bradley, F. C.;Nelson, M. J.;Que, L., Jr.;Wallick, D. E.
  21. J. Am. Chem. Soc. v.110 Cox, D. D.;Que, L., Jr.
  22. J. Am. Chem. Soc. v.113 Jang, H. G.;Cox, D. D.;Que, L., Jr.
  23. Angew. Chem. Int. Ed. Engl. v.34 Koch, W. O.;Kruger, H.-J.
  24. Bull. Korean Chem. Soc. v.18 Lim, J. H.;Lee, H.-J.;Lee, K.-B.;Jang, H. G.
  25. Angew. Chem., Int. Ed. Engl. v.36 Ito, M.;Que, L., Jr.
  26. Inorg. Chem. v.37 Ogihara, T.;Moro-oka, Y.
  27. J. Am. Chem. Soc. v.107 Pyrz, J. W.;Roe, A. L.;Stern, L. J.;Que, L., Jr.
  28. J. Am. Chem. Soc. v.102 Nanni, E. J., Jr.;Stallings, M. D.;Sawyers, D. T.
  29. NMR of Paramagnetic Molecules in Biological Systems Bertini, I.;Luchinat, C.
  30. J. Am. Chem. Soc. v.111 Wu, F.;Kurtz, Jr. D. M.
  31. Electron Spin Resonance; Elementary Theory and Practical Application Wertz, J. E.; Bolton, J. R.
  32. J. Am. Chem. Soc. v.113 Barbaro, P.;Bianchini, C.;Mealli, C.;Meli, A.
  33. J. Am. Chem. Soc. v.108 Funabiki, T.;Mizoguchi, A.;Sugimoto, T.;Tada, S.;Tsuji, M.;Yoshioka, T.;Sakamoto, H.;Takano, M.;Yoshida, S.
  34. Biochim. Biophys. Acta v.485 Que, L., Jr.;Lipscomb, J. D.;Munck, E.;Wood, J. M.

Cited by

  1. Novel Iron(III) Complexes of Tripodal and Linear Tetradentate Bis(phenolate) Ligands: Close Relevance to Intradiol-Cleaving Catechol Dioxygenases vol.42, pp.25, 2003, https://doi.org/10.1021/ic020569w
  2. A Reaction Intermediate Involved in Oxygenation of Catecholatoiron(III) Complexes with Molecular Oxygen — Relevance to Catechol Dioxygenases vol.33, pp.3, 2000, https://doi.org/10.1246/cl.2004.316
  3. Mechanistic study on regioselective oxygenation reaction of 1,2-quinones with peroxybenzoic acids: Relevant to mechanisms of catecholdioxygenases vol.251, pp.1, 2000, https://doi.org/10.1016/j.molcata.2006.02.002
  4. Iron(III) complexes of certain meridionally coordinating tridentate ligands as models for non-heme iron enzymes: The role of carboxylate coordination vol.100, pp.9, 2000, https://doi.org/10.1016/j.jinorgbio.2006.05.004
  5. Synthesis, structure, spectra and reactivity of iron(III) complexes of imidazole and pyrazole containing ligands as functional models for catechol dioxygenases vol.2009, pp.39, 2000, https://doi.org/10.1039/b903602d
  6. Novel square pyramidal iron(III) complexes of linear tetradentate bis(phenolate) ligands as structural and reactive models for intradiol-cleaving 3,4-PCD enzymes: Quinone formation vs. vol.39, pp.40, 2010, https://doi.org/10.1039/c0dt00171f
  7. Mononuclear iron(III) complexes of 3N ligands in organized assemblies: spectral and redox properties and attainment of regioselective extradiol dioxygenase activity vol.40, pp.9, 2000, https://doi.org/10.1039/c0dt01012j
  8. Iron(III) Catecholates for Cellular Imaging and Photocytotoxicity in Red Light vol.9, pp.9, 2000, https://doi.org/10.1002/asia.201402207