Tyrosinase is a key enzyme that has long been considered as a biomarker for melanoma as it catalyzes the oxidation of tyrosine and l-DOPA in melanogenesis. Recent studies also suggest a link between tyrosinase activity and Parkinson's disease; however, the mechanism of tyrosinase-mediated melanin formation in the brain is poorly understood. To better understand this connection, more advanced tools for the detection of tyrosinase in the brain are required. Herein, we successfully designed and synthesized a tyrosinase-targeting Gd(iii)-based MR contrast agent Tyr-GBCA 1. Tyr-GBCA 1 was synthesized by linking m-hydroxyphenyl to Gd-DOTA via a self-immolative linker. Tyr-GBCA 1 shows a 21% increase in the T1 relaxation rate (R1) in the presence of tyrosinase in artificial cerebral spinal fluid. Furthermore, Tyr-GBCA 1 is unreactive to hydrogen peroxide, which is a potential interferent in oxidation-based tyrosinase sensing systems. The reaction mechanism of the probe was studied by electrospray ionization (ESI) mass spectrometry and supports the cleavage of a reaction site.

中文翻译：

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基于d的MRI造影剂，用于检测酪氨酸酶。

酪氨酸酶是一种长期以来一直被认为是黑色素瘤生物标志物的关键酶，因为它在黑色素生成中催化酪氨酸和1-DOPA的氧化。最近的研究还表明酪氨酸酶活性与帕金森氏病之间存在联系。然而，人们对酪氨酸酶介导的黑色素在大脑中形成的机理了解甚少。为了更好地理解这种联系，需要更先进的工具来检测大脑中的酪氨酸酶。在本文中，我们成功设计并合成了靶向酪氨酸酶的Gd（iii）型MR造影剂Tyr-GBCA1。通过自消灭性接头将间羟基苯基与Gd-DOTA连接，合成了Tyr-GBCA 1。Tyr-GBCA 1显示在人工脑脊髓液中存在酪氨酸酶的情况下，T1弛豫率（R1）增加了21％。此外，Tyr-GBCA 1与过氧化氢无反应，过氧化氢是基于氧化的酪氨酸酶传感系统中的潜在干扰物。通过电喷雾电离（ESI）质谱研究了探针的反应机理，并支持了反应位点的裂解。