Ionizing radiation changes the electronic properties of melanin and enhances the growth of melanized fungi.
Ionizing radiation changes the electronic properties of melanin and enhances the growth of melanized fungi.
复制标题
DOI：
10.1371/journal.pone.0000457
复制
发表时间：
2007-05-23
期刊：
影响因子：
3.7
通讯作者：
Casadevall A
中科院分区：
文献类型：
--
作者：
Dadachova E;Bryan RA;Huang X;Moadel T;Schweitzer AD;Aisen P;Nosanchuk JD;Casadevall A
黑色素在自然界中普遍存在。在某些极端环境中，例如被放射性核素污染的土壤中，黑色素化的微生物通常是主要物种，这表明黑色素的存在对它们的生命周期是有益的。我们假设电离辐射可以改变黑色素的电子性质，并可能促进黑化微生物的生长。电离辐射改变了黑色素的电子自旋共振（ESR）信号，与电子结构的变化一致。相对于未照射的黑色素，照射的黑色素表现出其还原NADH的能力增加了4倍。HPLC分析黑色素从真菌生长在不同的基板上揭示了化学复杂性，黑色素组合物的生长基板上的依赖性和可能的影响，其与电离辐射的相互作用的黑色素组合物。XTT/MTT法显示黑色素C.新生黑色素细胞相对于非黑化细胞的电子转移特性，并且暴露于电离辐射增强了黑化细胞中黑色素的电子转移特性。暴露于比背景高约500倍的电离辐射的黑化皮肤病旺氏菌和新型隐球菌细胞生长显著更快，如由更高的CFU、更多的干重生物量和比未辐照黑化细胞或辐照的白化病突变体高3倍的14 C-乙酸盐掺入所指示的。此外，辐射促进了黑化球孢枝孢菌细胞在有限营养条件下的生长。黑色素暴露于电离辐射和可能的其他形式的电磁辐射，改变其电子特性。在暴露于电离辐射后，黑化的真菌细胞表现出相对于非黑化细胞的生长增加，提出了关于黑色素在能量捕获和利用中的潜在作用的有趣问题。
Melanin pigments are ubiquitous in nature. Melanized microorganisms are often the dominating species in certain extreme environments, such as soils contaminated with radionuclides, suggesting that the presence of melanin is beneficial in their life cycle. We hypothesized that ionizing radiation could change the electronic properties of melanin and might enhance the growth of melanized microorganisms. Ionizing irradiation changed the electron spin resonance (ESR) signal of melanin, consistent with changes in electronic structure. Irradiated melanin manifested a 4-fold increase in its capacity to reduce NADH relative to non-irradiated melanin. HPLC analysis of melanin from fungi grown on different substrates revealed chemical complexity, dependence of melanin composition on the growth substrate and possible influence of melanin composition on its interaction with ionizing radiation. XTT/MTT assays showed increased metabolic activity of melanized C. neoformans cells relative to non-melanized cells, and exposure to ionizing radiation enhanced the electron-transfer properties of melanin in melanized cells. Melanized Wangiella dermatitidis and Cryptococcus neoformans cells exposed to ionizing radiation approximately 500 times higher than background grew significantly faster as indicated by higher CFUs, more dry weight biomass and 3-fold greater incorporation of 14C-acetate than non-irradiated melanized cells or irradiated albino mutants. In addition, radiation enhanced the growth of melanized Cladosporium sphaerospermum cells under limited nutrients conditions. Exposure of melanin to ionizing radiation, and possibly other forms of electromagnetic radiation, changes its electronic properties. Melanized fungal cells manifested increased growth relative to non-melanized cells after exposure to ionizing radiation, raising intriguing questions about a potential role for melanin in energy capture and utilization.
登录
查看更多内容
DOI：
10.1016/s1387-2656(05)11004-7
发表时间：
2005-01-01
期刊：
BIOTECHNOLOGY ANNUAL REVIEW, VOL 11
影响因子：
--
作者：
Berridge, MV;Herst, PM;Tan, AS
通讯作者：
Tan, AS
影响因子：
4
作者：
HILL, HZ
通讯作者：
HILL, HZ
DOI：
10.1073/pnas.0503674102
发表时间：
2005-06-28
影响因子：
11.1
作者：
Beatty, JT;Overmann, J;Plumley, FG
通讯作者：
Plumley, FG
影响因子：
3.9
作者：
GAN, EV;HABERMAN, HF;MENON, IA
通讯作者：
MENON, IA
影响因子：
56.9
作者：
Redman, RS;Sheehan, KB;Henson, JM
通讯作者：
Henson, JM