Physico-chemical evaluation of rationally designed melanins as novel nature-inspired radioprotectors. 2009

Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
Department of Nuclear Medicine, Albert Einstein College of Medicine, New York, New York, United States of America.

BACKGROUND Melanin, a high-molecular weight pigment that is ubiquitous in nature, protects melanized microorganisms against high doses of ionizing radiation. However, the physics of melanin interaction with ionizing radiation is unknown. RESULTS We rationally designed melanins from either 5-S-cysteinyl-DOPA, L-cysteine/L-DOPA, or L-DOPA with diverse structures as shown by elemental analysis and HPLC. Sulfur-containing melanins had higher predicted attenuation coefficients than non-sulfur-containing melanins. All synthetic melanins displayed strong electron paramagnetic resonance (2.14.10(18), 7.09.10(18), and 9.05.10(17) spins/g, respectively), with sulfur-containing melanins demonstrating more complex spectra and higher numbers of stable free radicals. There was no change in the quality or quantity of the stable free radicals after high-dose (30,000 cGy), high-energy ((137)Cs, 661.6 keV) irradiation, indicating a high degree of radical stability as well as a robust resistance to the ionizing effects of gamma irradiation. The rationally designed melanins protected mammalian cells against ionizing radiation of different energies. CONCLUSIONS We propose that due to melanin's numerous aromatic oligomers containing multiple pi-electron system, a generated Compton recoil electron gradually loses energy while passing through the pigment, until its energy is sufficiently low that it can be trapped by stable free radicals present in the pigment. Controlled dissipation of high-energy recoil electrons by melanin prevents secondary ionizations and the generation of damaging free radical species.

UI MeSH Term Description Entries
D007980 Levodopa The naturally occurring form of DIHYDROXYPHENYLALANINE and the immediate precursor of DOPAMINE. Unlike dopamine itself, it can be taken orally and crosses the blood-brain barrier. It is rapidly taken up by dopaminergic neurons and converted to DOPAMINE. It is used for the treatment of PARKINSONIAN DISORDERS and is usually given with agents that inhibit its conversion to dopamine outside of the central nervous system. L-Dopa,3-Hydroxy-L-tyrosine,Dopaflex,Dopar,L-3,4-Dihydroxyphenylalanine,Larodopa,Levopa,3 Hydroxy L tyrosine,L 3,4 Dihydroxyphenylalanine,L Dopa
D008543 Melanins Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration. Allomelanins,Melanin,Phaeomelanins
D008970 Molecular Weight The sum of the weight of all the atoms in a molecule. Molecular Weights,Weight, Molecular,Weights, Molecular
D010087 Oxides Binary compounds of oxygen containing the anion O(2-). The anion combines with metals to form alkaline oxides and non-metals to form acidic oxides. Oxide
D010100 Oxygen An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration. Dioxygen,Oxygen-16,Oxygen 16
D011836 Radiation Tolerance The ability of some cells or tissues to survive lethal doses of IONIZING RADIATION. Tolerance depends on the species, cell type, and physical and chemical variables, including RADIATION-PROTECTIVE AGENTS and RADIATION-SENSITIZING AGENTS. Radiation Sensitivity,Radiosensitivity,Sensitivity, Radiation,Tolerance, Radiation,Radiation Sensitivities,Radiation Tolerances,Radiosensitivities,Sensitivities, Radiation,Tolerances, Radiation
D011839 Radiation, Ionizing ELECTROMAGNETIC RADIATION or particle radiation (high energy ELEMENTARY PARTICLES) capable of directly or indirectly producing IONS in its passage through matter. The wavelengths of ionizing electromagnetic radiation are equal to or smaller than those of short (far) ultraviolet radiation and include gamma and X-rays. Ionizing Radiation,Ionizing Radiations,Radiations, Ionizing
D003412 Cricetulus A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research. Hamsters, Armenian,Hamsters, Chinese,Hamsters, Grey,Armenian Hamster,Armenian Hamsters,Chinese Hamster,Chinese Hamsters,Grey Hamster,Grey Hamsters,Hamster, Armenian,Hamster, Chinese,Hamster, Grey
D003455 Cryptococcus neoformans A species of the fungus CRYPTOCOCCUS. Its teleomorph is Filobasidiella neoformans. Blastomyces neoformans,Debaryomyces neoformans,Filobasidiella neoformans,Lipomyces neoformans,Saccharomyces neoformans,Torula neoformans,Torulopsis neoformans,Cryptococcus neoformans var. grubii
D003545 Cysteine A thiol-containing non-essential amino acid that is oxidized to form CYSTINE. Cysteine Hydrochloride,Half-Cystine,L-Cysteine,Zinc Cysteinate,Half Cystine,L Cysteine

Related Publications

Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
December 2005, Experimental oncology,
Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
July 2012, Journal of medicinal chemistry,
Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
August 2008, Journal of medicinal chemistry,
Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
May 2019, Biomacromolecules,
Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
November 2020, International journal of molecular sciences,
Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
December 2023, Molecules (Basel, Switzerland),
Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
January 2017, Cognitive computation,
Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
January 2003, Acta poloniae pharmaceutica,
Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
December 2020, Drug development research,
Andrew D Schweitzer, and Robertha C Howell, and Zewei Jiang, and Ruth A Bryan, and Gary Gerfen, and Chin-Cheng Chen, and Dennis Mah, and Sean Cahill, and Arturo Casadevall, and Ekaterina Dadachova
June 2020, Scientific reports,
Copied contents to your clipboard!