Free radical scavenging properties of melanin interaction of eu- and pheo-melanin models with reducing and oxidising radicals.

2.50
Hdl Handle:
http://hdl.handle.net/10541/90774
Title:
Free radical scavenging properties of melanin interaction of eu- and pheo-melanin models with reducing and oxidising radicals.
Authors:
Rózanowska, Malgorzata; Sarna, Tadeusz; Land, Edward J; Truscott, T G
Abstract:
The human skin and eye melanin is commonly viewed as an efficient photoprotective agent. To elucidate the molecular mechanism of the melanin-dependent photoprotection, we studied the interaction of two synthetic melanins, dopa-melanin and cysteinyldopa-melanin, with a wide range of oxidising and reducing free radicals using the pulse radiolysis technique. We have found that although both types of free radicals could efficiently interact with the synthetic melanins, their radical scavenging properties depended, in a complex way, on the redox potential, the electric charge and the lifetime of the radicals. Repetitive pulsing experiments, in which the free radicals, probing the polymer redox sites, were generated from four different viologens, indicated that the eumelanin model had more reduced than oxidised groups accessible to reaction with the radicals. Although with many radicals studied, melanin interacted via simple one-electron transfer processes, the reaction of both melanins with the strongly oxidising peroxyl radical from carbon tetrachloride, involved radical addition. Our study suggests that the free radical scavenging properties of melanin may be important in the protection of melanotic cells against free radical damage, particularly if the reactive radicals are generated in close proximity to the pigment granules.
Affiliation:
Department of Biophysics, Institute of Molecular Biology, Jagiellonian University, Kraków, Poland.
Citation:
Free radical scavenging properties of melanin interaction of eu- and pheo-melanin models with reducing and oxidising radicals. 1999, 26 (5-6):518-25 Free Radic. Biol. Med.
Journal:
Free Radical Biology & Medicine
Issue Date:
Mar-1999
URI:
http://hdl.handle.net/10541/90774
DOI:
10.1016/S0891-5849(98)00234-2
PubMed ID:
10218640
Type:
Article
Language:
en
ISSN:
0891-5849
Appears in Collections:
All Paterson Institute for Cancer Research

Full metadata record

DC FieldValue Language
dc.contributor.authorRózanowska, Malgorzataen
dc.contributor.authorSarna, Tadeuszen
dc.contributor.authorLand, Edward Jen
dc.contributor.authorTruscott, T Gen
dc.date.accessioned2010-01-28T09:37:48Z-
dc.date.available2010-01-28T09:37:48Z-
dc.date.issued1999-03-
dc.identifier.citationFree radical scavenging properties of melanin interaction of eu- and pheo-melanin models with reducing and oxidising radicals. 1999, 26 (5-6):518-25 Free Radic. Biol. Med.en
dc.identifier.issn0891-5849-
dc.identifier.pmid10218640-
dc.identifier.doi10.1016/S0891-5849(98)00234-2-
dc.identifier.urihttp://hdl.handle.net/10541/90774-
dc.description.abstractThe human skin and eye melanin is commonly viewed as an efficient photoprotective agent. To elucidate the molecular mechanism of the melanin-dependent photoprotection, we studied the interaction of two synthetic melanins, dopa-melanin and cysteinyldopa-melanin, with a wide range of oxidising and reducing free radicals using the pulse radiolysis technique. We have found that although both types of free radicals could efficiently interact with the synthetic melanins, their radical scavenging properties depended, in a complex way, on the redox potential, the electric charge and the lifetime of the radicals. Repetitive pulsing experiments, in which the free radicals, probing the polymer redox sites, were generated from four different viologens, indicated that the eumelanin model had more reduced than oxidised groups accessible to reaction with the radicals. Although with many radicals studied, melanin interacted via simple one-electron transfer processes, the reaction of both melanins with the strongly oxidising peroxyl radical from carbon tetrachloride, involved radical addition. Our study suggests that the free radical scavenging properties of melanin may be important in the protection of melanotic cells against free radical damage, particularly if the reactive radicals are generated in close proximity to the pigment granules.en
dc.language.isoenen
dc.subject.meshFree Radical Scavengers-
dc.subject.meshHumans-
dc.subject.meshKinetics-
dc.subject.meshMelanins-
dc.subject.meshModels, Chemical-
dc.subject.meshOxidation-Reduction-
dc.subject.meshRose Bengal-
dc.subject.meshSpectrophotometry-
dc.titleFree radical scavenging properties of melanin interaction of eu- and pheo-melanin models with reducing and oxidising radicals.en
dc.typeArticleen
dc.contributor.departmentDepartment of Biophysics, Institute of Molecular Biology, Jagiellonian University, Kraków, Poland.en
dc.identifier.journalFree Radical Biology & Medicineen

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