• 关键词：辣根过氧化物酶  17α-乙炔基雌二醇  光降解  酶降解

• 基金项目：国家自然科学基金（No.21577059）

• 王梦杰
• 1. 生态环境部南京环境科学研究所, 国家环境保护土壤环境管理与污染控制重点实验室, 南京 210042;2. 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023

• 李建华
• 3. 南京理工大学环境与生物工程学院, 江苏省化学污染控制与资源化重点实验室, 南京 210094

• 彭建彪
• 4. 河南师范大学环境学院, 黄淮水环境污染与防治教育部重点实验室, 河南省环境污染控制重点实验室, 新乡 453007

• 高士祥
• 2. 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023

• 刘国强
• 1. 生态环境部南京环境科学研究所, 国家环境保护土壤环境管理与污染控制重点实验室, 南京 210042

• 张亚
• 1. 生态环境部南京环境科学研究所, 国家环境保护土壤环境管理与污染控制重点实验室, 南京 210042

• 摘要：过氧化物酶广泛存在于天然水体中,可利用腐殖质光照下产生的过氧化氢(H₂O₂)对雌激素的光转化过程产生影响,但过氧化物酶是否可直接影响雌激素的光转化尚不清楚.因此,本研究探索了在模拟光照条件下辣根过氧化物酶(HRP)对水体中17α-乙炔基雌二醇(EE2)光解的影响机制.结果发现,HRP的存在显著地促进了EE2的光降解,且促进作用随酶活的增大而增大,但失活的HRP对EE2的光降解没有明显影响.EE2可在光照条件下发生直接光解和自敏化光解.通过活性氧种类(ROS)猝灭实验推测EE2自敏化产生的ROS可激活HRP,引发了在光照条件下EE2的酶降解.分别曝氧气和氮气后,EE2在HRP溶液中的光酶协同降解分别被促进和抑制,进一步说明了ROS在光酶协同降解中的重要性.HRP的活性随着光照时间的增加缓慢下降,从而可以持续地促进EE2的光酶协同降解,推测HRP对EE2在天然水体中的衰减影响很大.本文可为深入认识雌激素的环境归趋补充科学数据.

• Abstract：Peroxidase is widespread in natural waters, and can affect photochemical process of estrogen via the interaction with H₂O₂ produced by humus photolysis. However, it is not clear whether peroxidase can directly affect the phototransformation of estrogen. In this study, the effect of horseradish peroxidase (HRP) on the photolysis of 17α-Ethinyl estradiol (EE2) in water under simulated sunlight was explored. The results show that the presence of HRP significantly promoted the photodegradation of EE2, and the promotion increased with the augment of enzyme activity, while inactivated HRP had no significant effect. EE2 could undergo direct photolysis and self-sensitized photolysis under the simulated sunlight. Based on the reactive oxygen species (ROS) quenching experiments, ROS generated by EE2 self-sensitization may activate HRP, which triggered the enzymatic degradation of EE2 under the simulated sunlight. The conclusion was reinforced via the phenomenon that the photolysis of EE2 in HRP solution was promoted and retarded by adding (O₂ purged) and eliminating (N₂ purged) dissolved oxygen, respectively. The activity of HRP decreased slowly during the irradiation process, resulting in continuously promoting the photo-enzymatic degradation of EE2, suggesting that HRP may play an importance role on the attenuation of EE2 in natural water bodies. This study will supplement scientific data for understanding the environmental fate of estrogen.

• Key words：horseradish peroxidase  17α-Ethinyl estradiol  photodegradation  enzyme degradation

• 
  摘要点击次数： 333 全文下载次数： 393