Abstract：
Nitroreductase (NTR) is a frequently used biomarker for the assessment of hypoxia level in tumors. As one of the main sources of enzymes, the dysfunction of lysosomes typically leads to various diseases. In this study, an NTR-triggered lysosome-targeting probe, M-TPE-P, was designed based on a tetraphenylethylene core. DFT calculation indicated that the probe possessed a narrow singlet-triplet energy gap (ΔEST), rendering it an efficient photosensitizer. The docking affinity of M-TPE-P to NTR revealed a strong structural match between them. Photophysical properties demonstrated that the probe exhibited high selectivity and sensitivity in a broad pH rang for detecting NTR with kcat/Km as 2.18 × 104 M-1 s-1. The detection limit was determined to be 53.6 ng/mL in 80 % PBS/DMSO solution. Cell imaging studies showed the probe could trace intracellular NTR behavior with green fluorescence. The colocalization analysis indicated its excellent lysosome-targeting specificity. In addition, the probe exhibited effective ROS generation ability and significant PDT effect after NIR irradiation, positioning it as a promising photosensitizer for cancer treatment.
摘要：
硝基还原酶（NTR）是评估肿瘤缺氧水平的常用生物标志物。作为酶的主要来源之一，溶酶体的功能障碍通常会导致各种疾病。在这项研究中,NTR触发的溶酶体靶向探针，M-TPE-P,是基于四苯基乙烯核设计的。DFT计算表明，探针具有窄的单线态-三重态能隙(ΔEST)，使它成为一种有效的光敏剂。M-TPE-P与NTR的对接亲和力揭示了它们之间的强结构匹配。光物理性质表明，该探针在kcat/Km为2.18×104M-1s-1的宽pH范围内检测NTR具有很高的选择性和灵敏度。检测极限在80%PBS/DMSO溶液中测定为53.6ng/mL。细胞成像研究表明，该探针可以用绿色荧光追踪细胞内NTR行为。共定位分析表明其优异的溶酶体靶向特异性。此外,该探针在NIR照射后表现出有效的ROS生成能力和显著的PDT效应，将其定位为癌症治疗的有前途的光敏剂。
