Design of spatiotemporally controllable ratiometric fluorescent imaging probe for endogenous tyrosinase

• 1、Hunan Provincial Key Laboratory of Cytochemistry, School of Chemistry and Chemical Engineering, Changsha University of Science and Technology, Changsha, 410114
• 2、Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081

Abstract：Tyrosinase is a key factor in the synthesis of melanin in living organisms, its abnormal activity can lead to imbalance in melanin metabolism, causing diseases such as melanoma, epilepsy and vitiligo, so it is of importance to develop a molecular tool that can precisely detect intracellular tyrosinase. In this paper, we designed and synthesized a controllable ratiometric tyrosinase fluorescent probe SRFP by using a light and enzyme sequential activation strategy, which couple the naphthalimide fluorophore with a light control group 2-nitrobenzyl caged enzyme recognition site 3-hydroxybenzoxy as a response unit. Because of the steric hindrance effect, tyrosinase is hard to bind with the caged enzyme substrate. If the substrate is released by light uncaging, the probe can response to tyrosinase. This design can avoid the false positive signal by the early activation of the probe during the process of entering the cell to realize the spatio-temporally controlled accurate imaging analysis of tyrosinase in the cell, and it is expected to be a useful tool for the diagnosis and drug screening of diseases related to abnormal tyrosinase concentration.

Keywords： Tyrosinase；Sequence activation；Fluorescent probe；Light control