State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, And Collaboration Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, China.
State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, And Collaboration Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, China.
Talanta. 2022 Mar 1;239:123078. doi: 10.1016/j.talanta.2021.123078. Epub 2021 Nov 17.
Alkaline phosphatase (ALP) exists in both normal and pathological tissues. Spatiotemporal variations in ALP levels can reveal its potential physiological functions and changes that occur during pathological conditions. However, it is still challenging to exploit fluorescent probes that can measure ALP activity under good spatial and temporal resolutions. Herein, enzyme-instructed self-assembly (EISA) was used to construct a high-performing analytical tool (MN-pY) to probe ALP activity. MN-pY alone (free state) showed negligible fluorescence but presented an almost 13-fold increase in fluorescence intensity in the presence of ALP (assembly state). Mechanism study indicated the increase in fluorescence intensity was due to hydrogelation and formation of supramolecular fibrils, mainly consisting of dephosphorylated MN-Y. The dephosphorylation and further fibrillation of MN-pY could induce the formation of a "hydrophobic pocket", leading to a further increase in fluorescence intensity. Moreover, MN-pY could selectively illuminate HeLa cells with a higher ALP expression but not LO2 cells with lower ALP levels, promising a potential application in cancer diagnosis.
碱性磷酸酶（ALP）存在于正常和病理组织中。ALP 水平的时空变化可以揭示其潜在的生理功能和病理条件下的变化。然而，开发能够在良好的时空分辨率下测量 ALP 活性的荧光探针仍然具有挑战性。在此，酶指导的自组装（EISA）被用于构建高性能的分析工具（MN-pY）来探测 ALP 活性。MN-pY 单独存在（自由状态）时几乎没有荧光，但在存在 ALP 时（组装状态）荧光强度增加了近 13 倍。机制研究表明，荧光强度的增加是由于水凝胶化和超分子原纤维的形成，主要由去磷酸化的 MN-Y 组成。MN-pY 的去磷酸化和进一步的纤维化会诱导形成一个“疏水性口袋”，导致荧光强度进一步增加。此外，MN-pY 可以选择性地照亮 ALP 表达较高的 HeLa 细胞，而不是 ALP 水平较低的 LO2 细胞，有望在癌症诊断中得到应用。
