Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, China.
State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, 200237, China.
Angew Chem Int Ed Engl. 2021 May 3;60(19):10756-10765. doi: 10.1002/anie.202101278. Epub 2021 Mar 26.
The tracking of cellular senescence usually depends on the detection of senescence-associated β-galactosidase (SA-β-gal). Previous probes for SA-β-gal with this purpose only cover a single dimension: the accumulation of this enzyme in lysosomes. However, this is insufficient to determine the destiny of senescence because endogenous β-gal enriched in lysosomes is not only related to senescence, but also to some other physiological processes. To address this issue, we introduce our fluorescent probes including a second dimension: lysosomal pH, since de-acidification is a unique feature of the lysosomes in senescent cells. With this novel design, our probes achieved excellent discrimination of SA-β-gal from cancer-associated β-gal, which enables them to track cellular senescence as well as tissue aging more precisely. Our crystal structures of a model enzyme E. coli β-gal mutant (E537Q) complexed with each probe further revealed the structural basis for probe recognition.
细胞衰老的追踪通常依赖于衰老相关β-半乳糖苷酶（SA-β-gal）的检测。之前用于该目的的 SA-β-gal 探针仅涵盖一个维度：这种酶在溶酶体中的积累。然而，这不足以确定衰老的命运，因为富含溶酶体的内源性β-半乳糖不仅与衰老有关，还与其他一些生理过程有关。为了解决这个问题，我们引入了包括第二个维度：溶酶体 pH 值的荧光探针，因为溶酶体去酸化是衰老细胞中溶酶体的一个独特特征。通过这种新的设计，我们的探针能够出色地区分 SA-β-gal 和与癌症相关的β-gal，从而能够更精确地追踪细胞衰老以及组织老化。我们对与每个探针结合的模型酶大肠杆菌β-半乳糖苷酶突变体（E537Q）的晶体结构的进一步研究揭示了探针识别的结构基础。
