Liu Jiao, Xu Jia-Kun, Yuan Hong, Wang Xiao-Juan, Gao Shu-Qin, Wen Ge-Bo, Tan Xiang-Shi, Lin Ying-Wu
School of Chemistry and Chemical Engineering, University of South China Hengyang 421001 China
Key Lab of Sustainable Development of Polar Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Lab for Marine Drugs and Byproducts of Pilot National Lab for Marine Science and Technology Qingdao 266071 China
RSC Adv. 2022 Jun 24;12(29):18654-18660. doi: 10.1039/d2ra02795j. eCollection 2022 Jun 22.
Malachite green (MG)-contaminated wastewater resulting from industrialization causes a global problem because of its toxicity and widespread usage. Compared with traditional physical and chemical approaches, biodegradation provides a new route for the degradation of MG. As promising candidates for native enzymes, artificial enzymes have received tremendous attention for potential applications due to unlimited possibilities based on precise design. In this study, we rationally engineered artificial enzymes based on myoglobin (Mb) and neuroglobin (Ngb). We introduced an aspartic acid (H64D mutation) in the heme pocket of Mb. A distal histidine (F43H mutation) was further introduced into H64D Mb to obtain a double mutant of F43H/H64D Mb. Moreover, we used A15C/H64D Ngb as designed recently for comparison studies. The H64D Mb, F43H/H64D Mb, and A15C/H64D Ngb were found to catalyze MG degradation efficiently, with activities much higher than those of native enzymes, such as dye-decolorizing peroxidase and laccase (83-205-fold). The crystal structure of H64D Mb was solved and the interactions of MG and H64D Mb and A15C/H64D Ngb were investigated by using both experimental and molecular docking studies. The biodegradation products of MG were also revealed by ESI-MS analysis. Therefore, these artificial enzymes have potential applications in the biodegradation of MG in textile industries and fisheries.
工业化产生的孔雀石绿（MG）污染废水因其毒性和广泛使用而成为一个全球性问题。与传统的物理和化学方法相比，生物降解为MG的降解提供了一条新途径。作为天然酶的有前途的候选者，人工酶由于基于精确设计具有无限可能性而在潜在应用中受到了极大关注。在本研究中，我们基于肌红蛋白（Mb）和神经球蛋白（Ngb）合理设计了人工酶。我们在Mb的血红素口袋中引入了天冬氨酸（H64D突变）。将一个远端组氨酸（F43H突变）进一步引入H64D Mb中以获得F43H/H64D Mb双突变体。此外，我们使用最近设计的A15C/H64D Ngb进行比较研究。发现H64D Mb、F43H/H64D Mb和A15C/H64D Ngb能有效催化MG降解，其活性比天然酶如染料脱色过氧化物酶和漆酶高得多（83 - 205倍）。解析了H64D Mb的晶体结构，并通过实验和分子对接研究研究了MG与H64D Mb和A15C/H64D Ngb的相互作用。通过电喷雾电离质谱（ESI-MS）分析也揭示了MG的生物降解产物。因此，这些人工酶在纺织工业和渔业中MG的生物降解方面具有潜在应用。
