美国波士顿大学Ji-Xin Cheng研究团队通过腈变色龙的实时中红外光热成像绘制活体系统中的酶活性图谱。这一研究成果于2024年1月8日在线发表在国际学术期刊《自然—方法学》上。

研究人员报告了腈类（C≡N）标记酶活性报告物的开发情况，并将其命名为腈类变色龙，用于底物和产物之间的峰值移动。为了对这些报告物进行实时成像，研究人员开发了一种激光扫描中红外光热成像系统，能够以300纳米的分辨率对酶底物和产物进行成像。

研究表明，将这些工具结合起来，可以绘制出不同酶的活性分布图谱，并测量它们在癌细胞、秀丽隐杆线虫和脑组织等活体系统中的相对催化效率，还可用于直接观察细胞凋亡过程中树突酶与磷酸酶之间的相互作用。这个方法普遍适用于各类酶，并能在酶的原生环境中对酶进行新的分析。

据悉，同时绘制生命系统中多种酶活性的空间图谱，可以阐明它们在健康和疾病中的功能。然而，基于监测荧光底物的方法非常有限。

附：英文原文

Title: Mapping enzyme activity in living systems by real-time mid-infrared photothermal imaging of nitrile chameleons

Author: He, Hongjian, Yin, Jiaze, Li, Mingsheng, Dessai, Chinmayee Vallabh Prabhu, Yi, Meihui, Teng, Xinyan, Zhang, Meng, Li, Yueming, Du, Zhiyi, Xu, Bing, Cheng, Ji-Xin

Issue&Volume: 2024-01-08

Abstract: Simultaneous spatial mapping of the activity of multiple enzymes in a living system can elucidate their functions in health and disease. However, methods based on monitoring fluorescent substrates are limited. Here, we report the development of nitrile (C≡N)-tagged enzyme activity reporters, named nitrile chameleons, for the peak shift between substrate and product. To image these reporters in real time, we developed a laser-scanning mid-infrared photothermal imaging system capable of imaging the enzymatic substrates and products at a resolution of 300nm. We show that when combined, these tools can map the activity distribution of different enzymes and measure their relative catalytic efficiency in living systems such as cancer cells, Caenorhabditis elegans, and brain tissues, and can be used to directly visualize caspase–phosphatase interactions during apoptosis. Our method is generally applicable to a broad category of enzymes and will enable new analyses of enzymes in their native context.

DOI: 10.1038/s41592-023-02137-x

Source: https://www.nature.com/articles/s41592-023-02137-x