TY - JOUR
T1 - The radioprotective properties of fungal melanin are a function of its chemical composition, stable radical presence and spatial arrangement
AU - Dadachova, Ekaterina
AU - Bryan, Ruth A.
AU - Howell, Robertha C.
AU - Schweitzer, Andrew D.
AU - Aisen, Philip
AU - Nosanchuk, Joshua D.
AU - Casadevall, Arturo
PY - 2008/4
Y1 - 2008/4
N2 - Melanized microorganisms are often found in environments with very high background radiation levels such as in nuclear reactor cooling pools and the destroyed reactor in Chernobyl. These findings and the laboratory observations of the resistance of melanized fungi to ionizing radiation suggest a role for this pigment in radioprotection. We hypothesized that the radioprotective properties of melanin in microorganisms result from a combination of physical shielding and quenching of cytotoxic free radicals. We have investigated the radioprotective properties of melanin by subjecting the human pathogenic fungi Cryptococcus neoformans and Histoplasma capsulatum in their melanized and non-melanized forms to sublethal and lethal doses of radiation of up to 8 kGy. The contribution of chemical composition, free radical presence, spatial arrangement, and Compton scattering to the radioprotective properties of melanin was investigated by high-performance liquid chromatography, electron spin resonance, transmission electron microscopy, and autoradiographic techniques. Melanin protected fungi against ionizing radiation and its radioprotective properties were a function of its chemical composition, free radical quenching, and spherical spatial arrangement.
AB - Melanized microorganisms are often found in environments with very high background radiation levels such as in nuclear reactor cooling pools and the destroyed reactor in Chernobyl. These findings and the laboratory observations of the resistance of melanized fungi to ionizing radiation suggest a role for this pigment in radioprotection. We hypothesized that the radioprotective properties of melanin in microorganisms result from a combination of physical shielding and quenching of cytotoxic free radicals. We have investigated the radioprotective properties of melanin by subjecting the human pathogenic fungi Cryptococcus neoformans and Histoplasma capsulatum in their melanized and non-melanized forms to sublethal and lethal doses of radiation of up to 8 kGy. The contribution of chemical composition, free radical presence, spatial arrangement, and Compton scattering to the radioprotective properties of melanin was investigated by high-performance liquid chromatography, electron spin resonance, transmission electron microscopy, and autoradiographic techniques. Melanin protected fungi against ionizing radiation and its radioprotective properties were a function of its chemical composition, free radical quenching, and spherical spatial arrangement.
KW - Compton scattering
KW - Electron spin resonance
KW - Fungi
KW - Ionizing radiation
KW - Melanin
KW - Radioprotection
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U2 - 10.1111/j.1755-148X.2007.00430.x
DO - 10.1111/j.1755-148X.2007.00430.x
M3 - Article
C2 - 18426412
AN - SCOPUS:42249104551
SN - 1755-1471
VL - 21
SP - 192
EP - 199
JO - Pigment Cell and Melanoma Research
JF - Pigment Cell and Melanoma Research
IS - 2
ER -