Zhang Jian, Tang Xiaojie, Qi Honglan, Li Zhao, He Xiaowei
The School of Information Sciences and Technology, Northwest University, Xi'an, 710127, China.
Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an, 710062, China.
Talanta. 2025 Apr 1;285:127377. doi: 10.1016/j.talanta.2024.127377. Epub 2024 Dec 14.
Butylcholinesterase (BChE) is a key enzyme in living system, closely related to liver and neurological diseases. It is very challenge to develop near-infrared (NIR) fluorescence probe methods for highly selective and sensitive detection of BChE in vivo. Based on the differences in active sites and spatial pockets between acetylcholinesterase (AChE) and BChE, a new NIR BChE-responsive fluorescence probe Probe-BChE (λ/λ = 600 nm/676 nm) was designed and synthesized by introducing dimethyl carbamate group as recognizing moiety to a NIR fluorophore hemicyanine skeleton. It was found that Probe-BChE specifically binds with BChE, rather than AChE, since BChE has a big cavity and strong intermolecular forces with Probe-BChE, which was supported by the molecular docking scores. The fluorescence method for the determination of BChE was developed with a detection limit of 0.14 U/mL BChE and high selectivity as well as short reaction time (∼3 s). The fluorescence imaging method using Probe-BChE efficiently image the levels of endogenous BChE in brains and main organs (heart, liver, spleen, lung and kidney) of Alzheimer's disease (AD) mice. The results reveal that the levels of endogenous BChE in old AD mice is higher than that in young AD mice, and endogenous BChE is enriched in the liver of AD mice. This work demonstrates that Probe-BChE is a promising fluorescence probe for imaging of endogenous BChE in AD mice. The design of NIR fluorescence probes for endogenous BChE in this work will promote to design NIR fluorescence probes for endogenous cholinesterase.
丁酰胆碱酯酶（BChE）是生命系统中的一种关键酶，与肝脏和神经系统疾病密切相关。开发用于在体内高选择性和灵敏检测BChE的近红外（NIR）荧光探针方法极具挑战性。基于乙酰胆碱酯酶（AChE）和BChE在活性位点和空间口袋上的差异，通过将氨基甲酸二甲酯基团作为识别基团引入近红外荧光团半菁骨架，设计并合成了一种新型的近红外BChE响应荧光探针Probe-BChE（λ/λ = 600 nm/676 nm）。研究发现Probe-BChE与BChE特异性结合，而非AChE，因为BChE有一个大的空腔且与Probe-BChE有很强的分子间作用力，这得到了分子对接分数的支持。建立了测定BChE的荧光方法，检测限为0.14 U/mL BChE，具有高选择性和短反应时间（约3秒）。使用Probe-BChE的荧光成像方法能够有效地成像阿尔茨海默病（AD）小鼠大脑和主要器官（心脏、肝脏、脾脏、肺和肾脏）中内源性BChE的水平。结果表明，老年AD小鼠体内内源性BChE的水平高于年轻AD小鼠，且内源性BChE在AD小鼠肝脏中富集。这项工作表明Probe-BChE是一种用于AD小鼠体内内源性BChE成像的有前景的荧光探针。本文中用于内源性BChE的近红外荧光探针的设计将促进内源性胆碱酯酶近红外荧光探针的设计。
