Key Laboratory of Public Health Safety of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, College of Public Health, Hebei University Baoding, 071002, Hebei, PR China.
Key Laboratory of Public Health Safety of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, College of Public Health, Hebei University Baoding, 071002, Hebei, PR China.
Anal Chim Acta. 2022 Dec 15;1236:340578. doi: 10.1016/j.aca.2022.340578. Epub 2022 Nov 2.
Monitoring the content and structural transition of human serum albumin (HSA) is valuable for diagnosing hypoalbuminemia and albuminuria and elucidating its transport function, respectively. Herein, we developed a multifunctional and efficient nanoprobe based on the self-assembly of an amphiphilic aggregation-induced emission luminogen, TPNN, for HSA detection and structure monitoring. TPNN molecules formed loose self-assembly in aqueous media and emitted faint fluorescence due to vigorous intramolecular motion. In the presence of HSA, a remarkable fluorescence enhancement accompanied by dissociation of TPNN assembly was observed due to the site-specific binding of TPNN to the middle long-narrow pocket of HSA. This binding blocked the intramolecular motion while producing a sensitive, selective, fast and stable fluorescence turn-on response to HSA, making TPNN assembly suitable for the HSA assay. TPNN assemblies also showed superior selectivity to HSA than bovine serum albumin (BSA) due to the distinct binding modes, and enabled us to distinguish the two homologous proteins. Furthermore, the generated TPNN-HSA complex underwent stepwise fluorescence quenching in the presence of protein denaturants and proteases, which revealed the process and kinetics of HSA unfolding and cleavage. TPNN assembly provides a powerful tool for accurate quantification of HSA in serum and urine and real-time monitoring of HSA structural transition.
监测人血清白蛋白（HSA）的含量和结构转变对于分别诊断低白蛋白血症和白蛋白尿以及阐明其转运功能具有重要意义。在此，我们开发了一种基于两亲性聚集诱导发光体 TPNN 自组装的多功能高效纳米探针，用于 HSA 检测和结构监测。在水介质中，TPNN 分子形成松散的自组装体，由于强烈的分子内运动，发出微弱的荧光。在 HSA 存在下，由于 TPNN 与 HSA 中部长而窄的口袋的特异性结合，观察到明显的荧光增强伴随着 TPNN 组装体的解离，这是由于 TPNN 与 HSA 的特异性结合而产生的。这种结合阻止了分子内运动，同时产生了对 HSA 的敏感、选择性、快速和稳定的荧光开启响应，使 TPNN 组装体适合用于 HSA 测定。由于结合模式的不同，TPNN 组装体对 HSA 比牛血清白蛋白（BSA）具有更高的选择性，使我们能够区分这两种同源蛋白质。此外，在存在蛋白质变性剂和蛋白酶的情况下，生成的 TPNN-HSA 复合物经历了逐步荧光猝灭，揭示了 HSA 展开和切割的过程和动力学。TPNN 组装体为血清和尿液中 HSA 的准确定量以及 HSA 结构转变的实时监测提供了有力工具。
