Guan Rui, Wang Yaoyao, Liu Hongbin, Zong Wansong, Shi Rongguang, Lan Jing, Zhao Xingchen, Zhao Zongshan
School of Environmental and Geography, Qingdao University, Qingdao 266071, China.
College of Geography and Environment, Shandong Normal University, Jinan 250014, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Aug 5;336:126031. doi: 10.1016/j.saa.2025.126031. Epub 2025 Mar 11.
Phthalates (PAEs), a category of plasticizers released from plastic products, have been widely detected in various environmental media and pose potential ecological risks to humans. Although the exposure risks of PAEs to organisms have been studied, the differences in the interactions between PAEs with different side chain lengths and biomolecules remain poorly understood at molecule levels. In this study, three commonly used PAEs (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP)) were employed to investigate the influence of their side chain lengths on interactions with catalase (CAT), a key antioxidant enzyme. The effects of PAEs on CAT enzyme activity and their interaction mechanisms were investigated using multi-spectral technique and molecular docking techniques. The results indicate that the order of reduced enzyme activity by PAEs is DMP > DEP > DBP, which inversely correlates with the alkyl chain length of PAEs. Molecular docking analysis reveal that DBP failing to bind to the central cavity of CAT likely contributes to its minimal impact on enzyme activity. The multiple spectrums demonstrate that the binding affinity of PAEs to CAT and the changes of CAT conformational structure align with the observed decline in enzyme activity as alkyl chain length increased. Since enzyme activity ties to its structure, the structural alterations in CAT induced by PAEs would inevitably affect its functional expression in vivo. This study offers a comprehensive assessment on the possible toxicity of PAEs with different side chain lengths at the molecular levels, providing insights into their ecological risks.
邻苯二甲酸酯（PAEs）是一类从塑料制品中释放出来的增塑剂，已在各种环境介质中被广泛检测到，并对人类构成潜在的生态风险。尽管已经研究了PAEs对生物体的暴露风险，但在分子水平上，不同侧链长度的PAEs与生物分子之间相互作用的差异仍知之甚少。在本研究中，使用了三种常用的PAEs（邻苯二甲酸二甲酯（DMP）、邻苯二甲酸二乙酯（DEP）、邻苯二甲酸二正丁酯（DBP））来研究它们的侧链长度对与关键抗氧化酶过氧化氢酶（CAT）相互作用的影响。采用多光谱技术和分子对接技术研究了PAEs对CAT酶活性的影响及其相互作用机制。结果表明，PAEs降低酶活性的顺序为DMP > DEP > DBP，这与PAEs的烷基链长度呈负相关。分子对接分析表明，DBP未能与CAT的中心腔结合可能是其对酶活性影响最小的原因。多种光谱表明，随着烷基链长度的增加，PAEs与CAT的结合亲和力以及CAT构象结构的变化与观察到的酶活性下降一致。由于酶活性与其结构相关，PAEs诱导的CAT结构改变将不可避免地影响其在体内的功能表达。本研究在分子水平上对不同侧链长度的PAEs的潜在毒性进行了全面评估，为其生态风险提供了见解。
