Esterase Coupled with the H2O2/Horseradish Peroxidase System Triggers Chemiluminescence from 2-Methyl-1-propenylbenzoate: A Potential Analytical Tool for Esterase Analysis
✍ Scribed by Boni Yavo; Ana Campa; Luiz H. Catalani
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 119 KB
- Volume
- 234
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
electronically excited products have been studied by
The hydrolysis of 2-methyl-1-propenylbenzoate cata-Cilento and co-workers (3, 4) since the mid-1970s. lyzed by esterase produces 2-methyl-1-propenol, which Among them, isobutanal (IBAL) was the most extencan be subsequently oxidized by the H 2 O 2 /horseradish sively studied. This HRP-catalyzed oxidation generates peroxidase (HRP) system to yield electronically extriplet acetone, as attested by its phosphorescent emiscited triplet acetone. The level of luminescence elicsion at 430 nm (5). A 1,2-dioxetane has been proposed ited by this species is proportional to total esterase as the key intermediate (Fig. 1). The chemiluminesused, making it possible to determine as little as 2 pmol cence can be amplified several orders of magnitude by of esterase. Yet, its intensity can be enhanced several addition of an appropriate sensitizer, like sodium 9,10orders of magnitude by fluorescent acceptors like sodibromoantracene-2-sulfonate (5) or fluorescein (6). dium 9,10-dibromoanthracene-2-sulfonate. The system Like in other peroxidase-catalyzed reactions, HRP works as a chemiluminescent reaction triggered by escompound I initiates and compound II propagates the terase and can be used to elaborate analytical assays
reaction. In fact, the true substrate of this enzymatic to determine its activity. This chemiluminescence is reaction was suggested to be the enol form of IBAL, 2also promoted by HRP conjugates instead of free HRP methyl-1-propenol, present in the keto-enol equiliband, hence, this simple reaction system can also be used to develop sensitive chemiluminescent immuno-rium, which is catalyzed by phosphate buffer. This was assays based upon peroxidase activity. ᭧ 1996 Academic confirmed by the use of the trimethylsilyl enol ether of Press, Inc.