Pyruvate kinase (PK) M2 (PKM2), a glycolytic enzyme, is a hallmark of different types of tumors and plays a significant role in the Warburg effect. However, there is no fluorescent probe for PKM2 that has been reported yet. In this study, TEPC466, a novel TEPP-46-based aggregation-induced emission (AIE) probe for the detection of PKM2, was designed, synthesized, and fully characterized by ¹H NMR, ¹³C NMR, and high-resolution mass spectrometry. When the fluorescent agent, coumarine, was conjugated to TEPP-46, the bioprobe TEPC466 showed a high degree of selectivity and sensitivity for the detection of PKM2 protein via the AIE effect. TEPC466 was then successfully applied in imaging the PKM2 protein in colorectal cancer cells with low toxicity. Moreover, structure-based modeling and the PK activity assay confirmed that TEPC466 has a better binding with PKM2 than TEPP-46, which suggests that TEPC466 could also be a good agonist of PKM2. Taken together, the bioprobe shows potential in selective detection of PKM2 and provides a useful tool for cancer diagnosis and therapy.

中文翻译：

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用于检测和生物成像活细胞中 PKM2 的基于 TEPP-46 的 AIE 荧光探针

丙酮酸激酶 (PK) M2 (PKM2) 是一种糖酵解酶，是不同类型肿瘤的标志，在 Warburg 效应中起着重要作用。然而，目前还没有关于 PKM2 的荧光探针的报道。在本研究中，TEPC466 是一种用于检测 PKM2 的新型基于 TEPP-46 的聚集诱导发射 (AIE) 探针，设计、合成并通过¹ H NMR、¹³C 核磁共振和高分辨率质谱。当荧光剂香豆素与 TEPP-46 结合时，生物探针 TEPC466 通过 AIE 效应对 PKM2 蛋白的检测显示出高度的选择性和灵敏度。随后，TEPC466 成功应用于低毒性结直肠癌细胞中 PKM2 蛋白的成像。此外，基于结构的建模和 PK 活性测定证实 TEPC466 与 PKM2 的结合比 TEPP-46 更好，这表明 TEPC466 也可能是 PKM2 的良好激动剂。总之，生物探针显示出选择性检测 PKM2 的潜力，并为癌症诊断和治疗提供了有用的工具。