Researchers designed and synthesized a new fluorescent probe to monitor the esterase enzyme, a type of lipase, in living cells. They published their findings in the journal Analytica Chimica Acta.

Abnormal esterase is associated with a number of human diseases such as obesity, cancer, and Wolman disease, a type of lysosomal acid lipase deficiency (LAL-D). Therefore, tracing the activity of the esterase enzyme is important and can allow to better monitor disease course as well as observe the effect of any treatment.

The probe called Y-1 was synthesized by conjugating acetylation of 4-hydroxy naphthalimide with a benzothiazole group.

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The team led by Weiying Lin from the Institute of Fluorescent Probes for Biological Imaging at the University of Jinan in Shandong, China reported that the probe has high sensitivity and selectivity, fast response, and photostability towards esterase.

Read more about LAL-D treatment

They also reported that the probe only emits fluorescence when it binds to esterase and found that esterase has a high affinity and hydrolysis to Y-1.

Using cell culture, the team showed that Y-1 could visualize esterase in a time-dependent manner within 15 minutes. Moreover, it could successfully be used to monitor the enzyme in zebrafish in a way that was consistent with the cell culture experiments.

“All these findings indicate that the robust probe Y-1 is a useful qualitative tool for detecting esterase in biological systems,” the researchers wrote. 

Wolman disease is the most severe type of LAL-D. It is caused by a mutation in the LIPA gene, which encodes lysosomal acid lipase that is responsible for metabolizing lipids.

When the esterase enzyme does not function properly, lipids accumulate inside cells causing damage and leading to symptoms such as abdominal distension, adrenal calcification, developmental delays, hepatomegaly, and hepatic failure.


Yin Y, Kong X, Li M, et al. Development of an esterase fluorescent probe based on naphthalimide-benzothiazole conjugation and its applications for qualitative detection of esterase in orlistat-treated biosamples. Anal Chim Acta. 2022;15(1190):339248. doi:10.1016/j.aca.2021.339248