Atomic elucidation of the cyclodextrin effects on DDT solubility and biodegradation.
Atomic elucidation of the cyclodextrin effects on DDT solubility and biodegradation.
复制标题
DOI：
10.1039/c6cp02790c
复制
发表时间：
2016-06
期刊：
影响因子：
--
通讯作者：
Baiping Ren;Mingzhen Zhang;Huipeng Gao;Jie Zheng;Lingyun Jia
中科院分区：
文献类型：
--
作者：
Baiping Ren;Mingzhen Zhang;Huipeng Gao;Jie Zheng;Lingyun Jia
滴滴涕（1,1,1-三氯-2.2-双（对氯苯）乙烷）是滥用最严重的杀虫剂之一，对人类健康和环境应用都是一种高度危险的成分。滴滴涕的生物降解成无毒、无害环境的成分受到滴滴涕生物利用度差的严重限制。在这项工作中，我们结合实验和分子模拟研究了三种环糊精（α-， β-和γ-CD）对它们与DDT的结构特异性相互作用的影响，特别是与DDT的溶解度和生物降解性的关系。结果发现，这三种CDs均能通过其内部疏水腔和不同的结合亲和取向与DDT结合，表明它们具有提高DDT溶解度的能力。与DDT与β-/γ-CDs通过完全DDT埋入模式的强结合不同，α-CD通过部分DDT埋入模式与DDT的结合相对较弱，这使得DDT在脂膜界面很容易与α-CD分离，随后DDT渗透到细胞膜内并穿过细胞膜。DDT与CDs之间不同的结合模式解释了为什么只有α-CD可以通过同时增加DDT的水溶性和膜相互作用来促进其生物利用度和生物降解。这项工作为进一步修饰和优化这三种CDs以提高其溶解性和滴滴涕的生物降解性提供了基于结构的结合信息。
DDT (1,1,1-trichloro-2.2-bis(p-chlorophenyl)ethane), one of the most abused insecticides, is a highly hazardous component for both human health and environmental applications. The biodegradation of DDT into non-toxic, environmentally benign components is strongly limited by the poor bioavailability of DDT. In this work, we combined experiments and molecular simulations to examine the effect of three cyclodextrins (α-, β-, and γ-CD) on their structure-specific interactions with DDT, specifically in relation to DDT solubility and biodegradability. It was found that all three CDs were able to bind to DDT with their inner hydrophobic cavity and different binding affinities and orientations, demonstrating their ability to improve DDT solubility. Different from the strong binding between DDT and β-/γ-CDs via a fully DDT bury mode, α-CD had a relatively weak binding with DDT via a partial DDT bury mode, which allowed DDT to be readily disassociated from α-CD at the lipid membrane interface, followed by DDT permeation into and across the cell membrane. The different binding modes between DDT and CDs explain why only α-CD can promote the bioavailability and biodegradation of DDT by simultaneously increasing its aqueous solubility and membrane interaction. This work provides structural-based binding information for the further modification and optimization of these three CDs to enhance their solubility and biodegradability of DDT.