Serum copper levels are biomarkers for copper-related diseases. Quantification of levels of free copper (not bound to proteins) in serum is important for diagnosing Wilson's disease, in which the free copper concentration is elevated. Bioluminescence is commonly used in point-of-care diagnostics, but these assays require genetically engineered luciferase. Here, we developed a luciferase-independent copper detection platform. A luminogenic caged coelenterazine analogue (TPA-H1) was designed and synthesized to detect copper ions in human serum. TPA-H1 was developed by introducing a tris[(2-pyridyl)-methyl]amine (TPA) ligand, which is a Cu⁺ cleavable caging group, to the carbonyl group at the C-3 position of the imidazopyrazinone scaffold. The luciferin, named HuLumino1, is the product of the cleavage reaction of TPA-H1 with a copper ion and displays “turn-on” bioluminescence signals specifically with human serum albumin, which can be used to quantitatively analyse copper ions. TPA-H1 exhibited a fast cleavage of the protective group, high specificity, and high sensitivity for copper over other metal ions. This novel caged coelenterazine derivative, TPA-H1, can detect free copper ions in serum in a simple “mix-and-read” manner.

中文翻译：

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使用笼状腔肠素类似物的混合读取生物发光铜检测平台

血清铜水平是铜相关疾病的生物标志物。血清中游离铜（未与蛋白质结合）水平的定量对于诊断威尔森氏病很重要，其中游离铜浓度升高。生物发光常用于床旁诊断，但这些检测需要基因工程荧光素酶。在这里，我们开发了一个不依赖荧光素酶的铜检测平台。设计并合成了发光笼状腔肠素类似物 ( TPA-H1 ) 以检测人血清中的铜离子。TPA-H1是通过引入三 [(2-吡啶基)-甲基] 胺 (TPA) 配体开发的，它是一种 Cu ⁺可裂解的笼基，连接到咪唑并吡嗪酮支架 C-3 位的羰基。荧光素，名为 HuLumino 1，是TPA-H1与铜离子裂解反应的产物，显示“开启”生物发光信号，特别是人血清白蛋白，可用于定量分析铜离子。与其他金属离子相比，TPA-H1表现出保护基团的快速裂解、高特异性和对铜的高灵敏度。这种新型笼状腔肠素衍生物TPA-H1可以通过简单的“混合读取”方式检测血清中的游离铜离子。