Preferences help
enabled [disable] Abstract
Number of results
2015 | 60 | 3 | 475-481
Article title

The acid-catalyzed interaction of melanin with nitrite ions. An EPR investigation

Title variants
Languages of publication
The interaction of synthetic dihydroxyphenylalanine (DOPA) melanin (DM) with nitrite ions, NO2−, in the pH 3.6–7.0 range, has been investigated using electron paramagnetic resonance (EPR). We found that especially at pH <5.5 (from ca. 5.5 to 3.6) the reaction of DM with nitrite generated large quantities of new melanin radicals, which implies the involvement of nitrous acid, HNO2, in the radical formation process. Measurements carried out at constant pH of 3.6 showed that the melanin signal increased together with nitrite concentration, reaching a plateau level which was more than fourfold larger compared to the initial signal amplitude observed in a nitrite-free buffer of the same pH. The effects of nitrite and DM concentrations on the melanin-free radical content were also investigated. It is proposed that the radicals are generated by one electron oxidation of melanin ortho-hydroquinone groups to ortho-semiquinones by HNO2 or related nitrogen oxides such as NO2• radicals. The possible involvement of nitric oxide (•NO) and peroxynitrite (ONOO−) in DM oxidation was also examined. In air-free solutions, nitric oxide per se did not generate melanin radicals; however, in the presence of oxygen a marked increase in the melanin EPR signal intensity was observed. This result is interpreted in terms of the generation of radicals via the oxidation of DM by peroxynitrite. Our findings suggest that melanin can function as a natural scavenger of nitrous acid and some nitrous acid-derived species. This property may be relevant to physiological functions of melanin pigments in vivo.
Physical description
1 - 7 - 2015
1 - 10 - 2014
30 - 1 - 2015
6 - 8 - 2015
  • 1. Reszka, K., & Jimbow, K. (1993). Electron donor and acceptor properties of melanin pigments in the skin. In J. Fuchs & L. Packer (Eds.), Oxidative stress in dermatology (pp. 287–320). New York: Marcel Dekker, Inc.
  • 2. Sealy, R. C. (1984). Free radicals in melanin formation, structure and reactions. In D. Armstrong, R. S. Sohal, R. G. C. Cutler & T. R. Slater (Eds.), Free radicals in molecular biology, aging and disease (pp. 67–76). New York: Raven Press.
  • 3. Prota, G. (1992). The role of peroxidase in melanogenesis revisited. Pigment Cell Res., Suppl. 2, 25–31. DOI: 10.1111/j.1600-0749.1990.tb00344.x.[Crossref]
  • 4. Chio, S. S., Hyde, J. S., & Sealy, R. C. (1982). Paramagnetism in melanins: pH dependence. Arch. Biochem. Biophys., 215(1), 100–106. DOI: 10.1016/0003-9861(82)90283-1.[Crossref]
  • 5. Lukiewicz, S., Reszka, K., & Matuszak, Z. (1980). Simultaneous electrochemical-electron spin resonance (SEESR) studies on natural and synthetic melanins. Bioelectrochem. Bioenergetics, 7(1), 153–165. DOI: 10.1016/0302-4598(80)87037-1.[Crossref]
  • 6. Reszka, K. J., & Chignell, C. F. (1993). EPR and spin-trapping investigation of free radicals from the reaction of 4-methoxybenzenediazonium tetrafluoroborate with melanin and melanin precursors. J. Am. Chem. Soc., 115(17), 7752–7760. DOI: 10.1021/ja00070a021.[Crossref]
  • 7. Felix, C. C., Hyde, J. S., Sarna, T., & Sealy, R. C. (1978). Interactions of melanin with metal ions. Electron spin resonance evidence for chelate complexes of metal ions with free radicals. J. Am. Chem. Soc., 100(12), 3922–3926. DOI: 10.1021/ja00480a044.[Crossref]
  • 8. Dunford, R., Land, E. J., Rozanowska, M., Sarna, T., & Truscott, T. G. (1995). Interaction of melanin with carbon- and oxygen-centered radicals from methanol and ethanol. Free Radic. Biol. Med., 19(6), 735–740.
  • 9. Sealy, R. C., Sarna, T., Wanner, E. J., & Reszka, K. (1984). Photosensitization of melanin: an electron spin resonance study of sensitized radical production and oxygen consumption. Photochem. Photobiol., 40(4), 453–459. DOI: 10.1111/j.1751-1097.1984.tb04617.x.[Crossref]
  • 10. Joshi, M., Strandhoy, J., & White, W. (1996). Nitric oxide synthase activity is up-regulated in melanoma cell lines: a potential mechanism for metastases formation. Melanoma Res., 6(2), 121–126.[Crossref]
  • 11. Xie, K., Huang, S., Dong, Z., Juang, S.-H., Gutman, M., Xie, Q.-W., Nathan, C., & Fidler, I. J. (1995). Transfection with the inducible nitric oxide synthase gene suppresses tumorigenicity and abrogates metastasis by K-1735 murine melanoma cells. J. Exp. Med., 181(4), 1333–1343. DOI: 10.1084/jem.181.4.1333.[Crossref]
  • 12. Xie, K., Donng, Z., & Fidler, I. J. (1996). Activation of nitric oxide synthase gene for inhibition of cancer metastasis. J. Leukoc. Biol., 59(6), 797–803.
  • 13. Dong, Z., Straroselsky, A. H., Qi, X., Xie, K., & Fidler, I. J. (1994). Inverse correlation between expression of inducible nitric oxide synthase activity and production of metastasis in K-1735 murine melanoma cells. Cancer Res., 54(3), 789–793.
  • 14. Nathan, C. F., & Hibbs, J. B. Jr (1991). Role of nitric oxide synthesis in macrophage antimicrobial activity. Curr. Opin. Immunol., 3(1), 65–70. DOI: 10.1016/0952-7915(91)90079-G.[Crossref]
  • 15. Jenkins, D. C., Charles, I. G., Thomsen, L. L., Moss, D. W., Holmes, L. S., Baylis, S. A., Rhodes, P., Westmore, K., Emson, P. C., & Moncada, S. (1995). Roles of nitric oxide in tumor growth. Proc. Natl. Acad. Sci. USA, 92(10), 4392–4396.[Crossref]
  • 16. Salvemini, D., De Nucci, G., Gryglewski, R. J., & Vane, J. R. (1989). Human neutrophils and mononuclear cells inhibit platelet aggregation by releasing a nitric oxide-like factor. Proc. Natl. Acad. Sci. USA, 86, 6328–6332.[Crossref]
  • 17. Tannock, I. F., & Rotin, D. (1989). Acid pH in tumors and its potential for therapeutic exploitation. Cancer Res., 49(16), 4373–4383.
  • 18. Vitturi, D. A., & Patel, R. P. (2011). Current perspectives and challenges in understanding the role of nitrite as an integral player in nitric oxide biology and therapy. Free Radic. Biol. Med., 51(4), 805–812. DOI: 10.1016/j.freeradbiomed.2011.05.037.[Crossref][WoS]
  • 19. Bhatnagar, V., Anjaiah, S., Puri, N., Darshanam, B. N. A., & Ramaiah, A. (1993). pH of Melanosomes of B 16 murine melanoma is acidic: Its physiological importance in the regulation of melanin biosynthesis. Arch. Biochem. Biophys., 307(1), 183–192.
  • 20. Seiji, M., & Kukicha, A. (1969). Acid phosphatase activity in melanosomes. J. Invest. Dermatol., 52(2), 212–216. DOI: 10.1038/jid.1969.33.[Crossref]
  • 21. Ebbing, D. D. (1990). General chemistry, 3rd ed. Boston: Houghton Mifflin Company.
  • 22. Beckman, J. S., Chen, J., Ischiropoulos, H., & Crow, J. P. (1994). Oxidative chemistry of peroxynitrite. In L. Packer (Ed.), Oxygen radicals in biological systems, Part C (Vol. 233, pp. 229–240). San Diego: Academic Press.
  • 23. Hughes, M. N., & Nicklin, H. G. (1968). The chemistry of pernitrites. Part I. Kinetics of decomposition of pernitrous acid. J. Chem. Soc. A, 1968, 450–452. DOI: 10.1039/J19680000450.[Crossref]
  • 24. Duling, D. (1994). Simulation of multiple isotropic spin-trap EPR spectra. J. Magn. Reson., Series B, 104(2), 105–110.[Crossref]
  • 25. Korytowski, W., & Sarna, T. (1990). Bleaching of melanin pigments. Role of copper ions and hydrogen peroxide in autooxidation and photooxidation of synthetic dopa-melanin. J. Biol. Chem., 265(21), 12410–12416.
  • 26. Bielski, B., Cabelli, D. E., Arudi, R. L., & Ross, A. B. (1985) Reactivity of HO2/O2− radicals in aqueous solution. J. Phys. Chem. Ref. Data, 14(4), 1041–1096.[Crossref]
  • 27. Huie, R. E., & Padmaja, S. (1993) The reaction of NO with superoxide. Free Radic. Res. Commun., 18(4), 195–199. DOI: 10.3109/10715769309145868.[Crossref]
  • 28. Davies, K. M., Wink, D. A., Saavedra, J. E., & Keefer, L. K. (2001). Chemistry of the diazeniumdiolates. 2. Kinetics and mechanism of dissociation to nitric oxide in aqueous solution. J. Am. Chem. Soc., 123(23), 5473–5481. DOI: 10.1021/ja002899q.[Crossref]
  • 29. Beake, B. D., Moodie, R. B., & Sandall, P. B. (1994). The kinetics and mechanism of oxidation of hydroquinone and chlorohydroquinone in the presence of nitrous acid in aqueous acid solution. J. Chem. Soc., Perkin Trans., 2, 957–960. DOI: 10.1039/P29940000957.[Crossref]
  • 30. Reszka, K. J., Matuszak, Z., & Chignell, C. F. (1998). Lactoperoxidase-catalyzed oxidation of melanin by reactive nitrogen species derived from nitrite – An EPR study. Free Radic. Biol. Med., 25(2), 208–216. DOI: 10.1016/S0891-5849(98)00058-6.[Crossref]
  • 31. Ford, P. C., Wink, D. A., & Stanbury, D. M. (1993). Autoxidation kinetics of aqueous nitric oxide. FEBS Lett., 326(1/3), 1–3. .[Crossref]
  • 32. Pryor, W. A., & Squadrito, G. L. (1995). The chemistry of peroxynitrite: a product from the reaction of nitric oxide with superoxide. Am. J. Physiol. (Lung Cell Mol. Physiol.), 268(5), L699–L722.
  • 33. Beckman, J. S., Beckman, T. W., Chen, J., Marshall, P. A., & Freeman, B. A. (1990). Apparent hydroxyl radical production by peroxynitrite: implications for endothelial injury from nitric oxide and superoxide. PNAS, 87(4), 1620–1624. DOI: 10.1073/pnas.87.4.1620.[Crossref]
  • 34. Korytowski, W., Pilas, B., Sarna, T., & Kalyanaraman, B. (1987). Photoinduced generation of hydrogen peroxide and hydroxyl radicals in melanins. Photochem. Photobiol., 45(2), 185–190. DOI: 10.1111/j.1751-1097.1987.tb05362.x.[Crossref]
  • 35. Wang, Y., & Casadevall, A. (1994). Susceptibility of melanized and nonmelanized Cryptococcus neoformans to nitrogen- and oxygen-derived oxidants. Infect. Immun., 62(7), 3004–3007.
Document Type
Publication order reference
YADDA identifier
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.