An advanced method for the determination of carboxyl methyl esterase activity using gas chromatography–chemical ionization–mass spectrometry

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Analytical technologies in the biomedical and life sciences, 2008-02, Vol.863 (1), p.80-87
• Main Authors: Koo, Yeon Jong, Yoon, Eunsil, Song, Jong Tae, Seo, Hak Soo, Kim, Jeong-Han, Lee, Yin-Won, Lee, Jong Seob, Cheong, Jong-Joo, Choi, Yang Do
• Format: Article
• Language: English
• Subjects: Analysis; Analytical, structural and metabolic biochemistry; Arabidopsis - chemistry; Biological and medical sciences; Carboxyl methyl esterase; Carboxylic Ester Hydrolases - analysis; Chromatography, Thin Layer; Escherichia coli - chemistry; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry; Gas chromatography–mass spectroscopy; General pharmacology; Hydrogen-Ion Concentration; Indicators and Reagents; Indole 3-acetic acid methyl ester; Jasmonic acid methyl ester; Kinetics; Medical sciences; Pharmacology. Drug treatments; Plant Growth Regulators - analysis; Plants - chemistry; Reference Standards; Salicylic acid methyl ester; Trimethylsilyl Compounds
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/j.jchromb.2008.01.015

We developed a quantitative method for the determination of methyl esterase activity, analyzing substrate specificity against three major signal molecules, jasmonic acid methyl ester (MeJA), salicylic acid methyl ester (MeSA), and indole-3-acetic acid methyl ester (MeIAA). We used a silylation reagent for chemical derivatization and used gas chromatography (GC)–mass spectroscopy in analyses, for high precision. To test this method, an Arabidopsis esterase gene, AtME8, was expressed in Escherichia coli, and then the kinetic parameters of the recombinant enzyme were determined for three substrates. Finally, this method was also applied to the direct quantification of phytohormones in petals from lilies and roses.