Abstract:

Organic halides, serving as critical structural motifs in pharmaceuticals, agrochemicals, and advanced materials, are conventionally synthesized through energy-intensive processes involving toxic reagents and hazardous waste generation. In contrast, halogenases-nature's biocatalytic tools-catalyze regio- and stereoselective halogenation under environmentally benign conditions, offering a paradigm shift toward sustainable chemistry. This review systematically consolidates recent breakthroughs in halogenase research, emphasizing mechanistic insights, engineering innovations, and scalable industrial applications. Halogenases are mechanistically classified into three major families: flavin-dependent enzymes that mediate electrophilic halogenation via transient hypohalous acid intermediates; non-heme iron/α-ketoglutarate-dependent oxygenases driving radical-based halogenation pathways; and S-adenosylmethionine (SAM)-dependent enzymes facilitating rare nucleophilic halogenation. Cutting-edge structural biology techniques, complemented by computational simulations, have resolved dynamic substrate-enzyme interactions and transient catalytic states, enabling the rational design of halogenases with tailored reactivity. Concurrently, the integration of bioinformatics tools and high-throughput screening platforms has accelerated the discovery of novel halogenases from underexplored microbial niches, revealing unprecedented catalytic diversity. To bridge natural enzymatic capabilities with industrial demands, interdisciplinary strategies are being deployed: Directed evolution optimizes activity and stability under non-native conditions; computational protein design rebuilds substrate-binding pockets for non-canonical substrates; and synthetic biology frameworks reconstruct halogenation pathways in engineered microbial hosts. These efforts collectively expand the biocatalytic toolbox, allowing precise halogenation of complex scaffolds, including aromatic systems, aliphatic chains, and heterocycles. In industrial contexts, enzymatic halogenation is gaining traction for synthesizing high-value compounds-ranging from antibiotic derivatives and antitumor agents to crop protection molecules-while circumventing traditional reliance on heavy metal catalysts, extreme temperatures, and halogenated solvents. Emerging applications further extend to the functionalization of biomaterials and fine chemicals, underscoring the versatility of halogenases. Future advancements will likely harness machine learning algorithms to decode sequence-activity landscapes and predict multi-enzyme cascades for tandem halogenation-functional group interconversions. Such developments align with global sustainability agendas, positioning halogenases as cornerstone biocatalysts in the transition toward circular chemical economies. This review highlights the convergence of enzymology, systems biology, and green chemistry in unlocking the full potential of halogenases, paving the way for next-generation biomanufacturing.

Key words: halogenase, biosynthesis, organichalide, enzyme engineering, directed evolution

摘要：

有机卤化物在医药和农业领域应用广泛，但其化学合成过程污染严重。卤化酶是实现化合物卤素修饰及功能改善的重要工具。与化学合成不同，卤化酶可以实现有机结构特定位置的精准卤化，并且反应条件温和，避免了苛刻反应条件以及有毒试剂的使用，其催化反应的过程符合绿色化学要求。本文综述了卤化酶在生物合成中的最新研究进展及其在工业生产中的潜在应用。首先，简要回顾了卤化酶的分类、结构特征及催化机制的研究现状，并介绍了相关领域的最新进展。其次，总结了近年来通过基因组挖掘、定向进化和合成生物学等技术发掘新酶资源、优化酶催化性能及扩展酶应用范围的策略。然后，探讨了工程化卤化酶在药物、农药及其他生物活性物质合成中的具体应用案例。最后，讨论了在机器学习迅速发展的背景下，卤化酶研究的未来发展趋势。

关键词: 卤化酶, 生物合成, 有机卤化物, 酶工程, 定向进化