The radioprotective properties of fungal melanin are a function of its chemical composition, stable radical presence and spatial arrangement

被引：130
作者：
Dadachova, Ekaterina [1 ]
Bryan, Ruth A. [1 ]
Howell, Robertha C. [1 ]
Schweitzer, Andrew D. [1 ]
Aisen, Philip [2 ]
Nosanchuk, Joshua D. [3 ,4 ]
Casadevall, Arturo [3 ,4 ]
机构：
[1] Albert Einstein Coll Med, Dept Nucl Med, Bronx, NY 10467 USA
[2] Albert Einstein Coll Med, Dept Physiol & Biophys, Bronx, NY 10467 USA
[3] Albert Einstein Coll Med, Dept Med, Bronx, NY 10467 USA
[4] Albert Einstein Coll Med, Dept Microbiol & Immunol, Bronx, NY 10467 USA
来源：
PIGMENT CELL & MELANOMA RESEARCH | 2008年 / 21卷 / 02期
关键词：
melanin; ionizing radiation; radioprotection; fungi; compton scattering; electron spin resonance;
D O I：
10.1111/j.1755-148X.2007.00430.x
中图分类号：
R73 [肿瘤学];
学科分类号：
100214 ;
摘要：
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.
引用
收藏
页码：192 / 199
页数：8
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