Hu Shimeng, Yuan Dong, Liu Yang, Zhao Lining, Guo Hongli, Niu Qigui, Zong Wansong, Liu Rutao
School of Environmental Science and Engineering, Shandong University, America CRC for Environment & Health, Shandong Province 72# Jimo Binhai Road Qingdao Shandong 266237 P. R. China
Department of Chemistry and Chemical Engineering, Qilu Normal University 36# Lishan Road Jinan 250013 P. R. China.
RSC Adv. 2019 Oct 17;9(57):33368-33377. doi: 10.1039/c9ra02986a. eCollection 2019 Oct 15.
Alizarin red S (ARS) is a widespread mordant dye derived from alizarin. However, it was reported to be mutagenic and carcinogenic probably because it could induce oxidative damages in organisms. Catalase (CAT) is an important antioxidant enzyme defensing oxidative damages induced by xenobiotics. The underlying mechanisms of ARS interacting with CAT have not been clarified yet. This study is conducted to characterize the functional and conformational changes on CAT by ARS and the binding details to further investigate their interaction mechanisms. Under exposure of ARS at 5 μM, CAT activity was significantly decreased to 76.2%. Inhibition of CAT probably resulted in promotion of intracellular oxidative stress and pro-oxidant property of ARS. The interaction between ARS and CAT was proved to be spontaneous and exothermic. However, limited structural changes were observed according to spectroscopic results. Results showed that ARS prefers to bind with residues buried in the active site and could alter the activity of CAT, which were agree with the molecular docking results. This work proves the adverse effects of ARS on CAT mainly at molecular level and further highlights its potential risks to heath.
茜素红S（ARS）是一种源自茜素的广泛使用的媒染染料。然而，据报道它具有致突变性和致癌性，可能是因为它能在生物体中诱导氧化损伤。过氧化氢酶（CAT）是一种重要的抗氧化酶，可防御外源性物质诱导的氧化损伤。ARS与CAT相互作用的潜在机制尚未阐明。本研究旨在表征ARS对CAT的功能和构象变化以及结合细节，以进一步研究它们的相互作用机制。在5 μM的ARS暴露下，CAT活性显著降低至76.2%。CAT的抑制可能导致细胞内氧化应激的加剧和ARS的促氧化特性。ARS与CAT之间的相互作用被证明是自发的且放热的。然而，根据光谱结果观察到的结构变化有限。结果表明，ARS更倾向于与埋在活性位点的残基结合，并能改变CAT的活性，这与分子对接结果一致。这项工作证明了ARS对CAT的不利影响主要在分子水平，并进一步凸显了其对健康的潜在风险。
