State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, Jilin 130022, China.
University of Chinese Academy of Sciences , Beijing 100049, China.
Anal Chem. 2017 Oct 3;89(19):10529-10536. doi: 10.1021/acs.analchem.7b02739. Epub 2017 Sep 22.
As a well-known copper-containing oxidase, tyrosinase has been anticipated to serve as the biomarker of skin diseases. We describe here an exquisite label-free fluorescent and colorimetric dual-readout assay of its activity, inspired by the specific oxidation ability of monophenolamine substrates to catecholamines and a unique fluorogenic reaction between resorcinol and catecholamines. By employing commercially available tyramine as the model substrate (dopamine as the product), it is found that the tyrosinase-incubated tyramine solution exhibits obvious pale yellow with intense blue fluorescence in the presence of resorcinol and O, where the absorbance and fluorescence intensity are directly related to the concentration of added tyrosinase (i.e., the amount of conversion of tyramine to dopamine). The overall process of sensing tyrosinase activity takes less than 100 min at ambient temperature and pressure conditions with exceedingly simple operation procedure, explicit response mechanism, and formation of fluorophore with high quantum yield from scratch. Furthermore, such a convenient, rapid, cost-effective, and highly sensitive dual-readout assay exhibits promising prospect for the tyrosinase activity in extensive bioassays and clinic research as well as in screening potential tyrosinase inhibitors.
作为一种著名的含铜氧化酶，酪氨酸酶被预期作为皮肤疾病的生物标志物。我们在这里描述了一种基于单酚胺底物对儿茶酚胺的特殊氧化能力和间苯二酚与儿茶酚胺之间独特的荧光反应的酶活性的无标记荧光和比色双读数测定法。通过使用市售的酪胺作为模型底物（多巴胺作为产物），发现存在间苯二酚和 O 时，酪氨酸酶孵育的酪胺溶液呈现明显的浅黄色，并伴有强烈的蓝色荧光，其中吸光度和荧光强度与添加的酪氨酸酶的浓度（即，酪氨酸胺向多巴胺的转化率）直接相关。在环境温度和压力条件下，整个检测过程不到 100 分钟，操作步骤非常简单，响应机制明确，并且从头开始形成具有高量子产率的荧光团。此外，这种方便、快速、具有成本效益且高灵敏度的双读数测定法有望在广泛的生物测定和临床研究以及筛选潜在的酪氨酸酶抑制剂中应用。
