Jia Bingqing, Liu Yang, Geng Xudong, Li Yuezheng, Zhang Chengmei, Qu Yuanyuan, Liu Xiangdong, Zhao Mingwen, Yang Yanmei, Li Weifeng, Li Yong-Qiang
Institute of Advanced Interdisciplinary Science, School of Physics, Shandong University, Jinan 250100, China.
Laboratory Animal Center of Shandong University, Jinan 250012, China.
Research (Wash D C). 2025 Jun 3;8:0732. doi: 10.34133/research.0732. eCollection 2025.
Enzyme-photosensitizer (PS) conjugates hold great promise for clinical treatment of cancer and infectious diseases via catalysis-augmented photodynamic therapy (PDT). Compared to covalent coupling, physical binding utilizing noncovalent interactions provides a simple and nondestructive strategy to combine PS with enzymes. However, the mechanism of enzyme-PS physical combination remains largely unknown, and physically bonded enzyme-PS conjugates are rarely reported. Here, we systematically investigate the interacting behaviors of representative enzymes with one of the most popular PS of chlorin e6 (Ce6) and elucidate their binding dynamics and crucial determinants. Our results reveal that the positively charged and hydrophobic residues on the surface of enzymes are crucial determinants of Ce6 binding. In addition, we demonstrate that the positively charged surface area of enzymes can be employed as a reliable criterion for assessing and predicting the enzyme-Ce6 binding affinity. Guided by this criterion, we further construct catalase-Ce6 nanoconjugates (CAT-Ce6 NCs) with superior stability and robust photodynamic antimicrobial capability via physical binding. In a showcase treatment of methicillin-resistant (MRSA)-infected mouse model of subcutaneous abscess, CAT-Ce6 NCs enable hypoxia pathological microenvironment remodeling and bacteria elimination, realizing effective catalysis-augmented PDT. This study deciphers the physical binding mechanism of enzyme-PS and establishes a theoretical framework to facilitate the design and construction of outstanding enzyme-PS NCs for catalysis-augmented PDT.
酶-光敏剂（PS）缀合物通过催化增强光动力疗法（PDT）在癌症和传染病的临床治疗中具有巨大潜力。与共价偶联相比，利用非共价相互作用的物理结合为将PS与酶结合提供了一种简单且无损的策略。然而，酶-PS物理结合的机制在很大程度上仍然未知，并且很少有关于物理结合的酶-PS缀合物的报道。在此，我们系统地研究了代表性酶与最常用的光敏剂之一二氢卟吩e6（Ce6）的相互作用行为，并阐明了它们的结合动力学和关键决定因素。我们的结果表明，酶表面带正电荷和疏水的残基是Ce6结合的关键决定因素。此外，我们证明酶的带正电荷表面积可作为评估和预测酶与Ce6结合亲和力的可靠标准。在此标准的指导下，我们通过物理结合进一步构建了具有卓越稳定性和强大光动力抗菌能力的过氧化氢酶-Ce6纳米缀合物（CAT-Ce6 NCs）。在耐甲氧西林金黄色葡萄球菌（MRSA）感染的皮下脓肿小鼠模型的展示治疗中，CAT-Ce6 NCs能够重塑缺氧病理微环境并消除细菌，实现有效的催化增强PDT。本研究破译了酶-PS的物理结合机制，并建立了一个理论框架，以促进用于催化增强PDT的优异酶-PS NCs的设计和构建。
