Zhang Huixia, Chen Jun, Xie Ping
College of Life Sciences, Longyan University, Longyan 364000, PR China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming 650500, PR China.
Donghu Experimental Station of Lake Ecosystems, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
Int J Biol Macromol. 2025 Apr;298:139873. doi: 10.1016/j.ijbiomac.2025.139873. Epub 2025 Jan 13.
Cyanobacteria blooms are concerning due to algal toxins like microcystin-leucine arginine (MC-LR). Despite progress in detecting MC-LR and understanding its toxic effects, including calf thymus DNA (CT-DNA) damage, the mechanisms for fluorescent probe detection of MC-LR and its binding to CT-DNA are poorly understood. In this study, we designed three fluorescent probes for MC-LR detection. Probe 1, with an acidic recognition site, is effective but influenced by solution pH. Probe 2, featuring a benzene ring structure, shows stable detection regardless of pH. Probe 3 offers the best performance, combining a long-chain and benzene ring structure. This suggests that combining these structures is beneficial for MC-LR probe design. Using Probe 3, we observed a strong interaction between MC-LR and CT-DNA. UV absorption spectroscopy, circular dichroism (CD) spectra, and molecular docking techniques provided the first evidence of MC-LR binding to CT-DNA through intercalation, with a binding saturation value of 8.33, significantly impacting CT-DNA structure. This study introduces a novel strategy for designing fluorescent probes for MC-LR detection, along with new insights into the interactions between MC-LR and CT-DNA.
蓝藻水华令人担忧，因为存在微囊藻毒素 - 亮氨酸精氨酸（MC - LR）等藻类毒素。尽管在检测MC - LR以及了解其毒性作用（包括对小牛胸腺DNA（CT - DNA）的损伤）方面取得了进展，但对于MC - LR的荧光探针检测机制及其与CT - DNA的结合情况仍知之甚少。在本研究中，我们设计了三种用于检测MC - LR的荧光探针。探针1具有酸性识别位点，效果良好但受溶液pH值影响。探针2具有苯环结构，无论pH值如何都能实现稳定检测。探针3表现最佳，结合了长链和苯环结构。这表明结合这些结构有利于MC - LR探针的设计。使用探针3，我们观察到MC - LR与CT - DNA之间存在强烈相互作用。紫外吸收光谱、圆二色性（CD）光谱和分子对接技术首次证明MC - LR通过嵌入与CT - DNA结合，结合饱和值为8.33，对CT - DNA结构有显著影响。本研究介绍了一种设计用于检测MC - LR的荧光探针的新策略，以及对MC - LR与CT - DNA相互作用的新见解。
