Differential behaviors of silver nanoparticles and silver ions towards cysteine: Bioremediation and toxicity to Phanerochaete chrysosporium
Differential behaviors of silver nanoparticles and silver ions towards cysteine: Bioremediation and toxicity to Phanerochaete chrysosporium
复制标题
银纳米粒子和银离子对半胱氨酸的不同行为：对黄孢原毛平革菌的生物修复和毒性
DOI：
10.1016/j.chemosphere.2018.03.144
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发表时间：
2018-07-01
期刊：
影响因子：
8.8
通讯作者：
Chen, Guiqiu
中科院分区：
文献类型：
--
作者：
Huang, Zhenzhen;Zeng, Zhuotong;Chen, Guiqiu
银纳米颗粒 (AgNP) 在与水生环境中天然普遍存在的有机配体相互作用时可能发生转化，影响其运输、持久性、生物利用度以及随后对生物体的毒性。本研究从生物修复及其对黄孢原毛平革菌的毒性方面研究了AgNPs和银离子(Ag+)对半胱氨酸(Cys)的不同行为，半胱氨酸(Cys)是硫醇配体的代表氨基酸，易于与Ag+配位并接枝到纳米粒子表面。在AgNPs和Ag+胁迫下，补充不同浓度的半胱氨酸后，总Ag去除、2,4-二氯苯酚(2,4-DCP)降解、细胞外蛋白分泌和细胞活力都有一定程度的增强。然而，在用10μM AgNP和1μM Ag+处理的组中，添加5-50μM半胱氨酸后，观察到总Ag摄取明显减少，特别是在Cys:Ag摩尔比为5的情况下。在Ag+暴露下检测到的摄取模式比AgNP暴露下更稳定。此外，在没有半胱氨酸的情况下，所有 Ag+ 处理比高剂量 AgNP 更能显着刺激活性氧 (ROS) 的产生。然而，AgNP/Ag+胁迫下的半胱氨酸供应加剧了ROS水平，尽管在100μM Ag+时有所缓解，这表明半胱氨酸可能会加剧或略微减轻AgNPs和Ag+对黄孢青霉的毒性。获得的结果可能与 AgNP/Ag+-半胱氨酸复合物的不稳定性和生物利用度有关。 (C) 2018 Elsevier Ltd. 保留所有权利。
Potential transformations of silver nanoparticles (AgNPs) upon interaction with naturally ubiquitous organic ligands in aquatic environments influence their transport, persistence, bioavailability, and subsequent toxicity to organisms. In this study, differential behaviors of AgNPs and silver ions (Ag+) towards cysteine (Cys), an amino acid representative of thiol ligands that easily coordinate to Ag+ and graft to nanoparticle surfaces, were investigated in the aspects of bioremediation and their toxicity to Phanerochaete chrysosporium. Total Ag removal, 2,4-dichlorophenol (2,4-DCP) degradation, extracellular protein secretion, and cellular viability were enhanced to some extent after supplement of various concentrations of cysteine under stress of AgNPs and Ag+. However, an obvious decrease in total Ag uptake was observed after 5-50 mu M cysteine addition in the groups treated with 10 mu M AgNPs and 1 mu M Ag+, especially at a Cys:Ag molar ratio of 5. More stabilization in uptake pattern at this ratio was detected under Ag+ exposure than that under AgNP exposure. Furthermore, in the absence of cysteine, all Ag+ treatments stimulated the generation of reactive oxygen species (ROS) more significantly than high-dose AgNPs did. However, cysteine supply under AgNP/Ag+ stress aggravated ROS levels, albeit alleviated at 100 mu M Ag+, indicating that the toxicity profiles of AgNPs and Ag+ to P. chrysosporium could be exacerbated or marginally mitigated by cysteine. The results obtained were possibly associated with the lability and bioavailability of AgNP/Ag+-cysteine complexes. (C) 2018 Elsevier Ltd. All rights reserved.