Fluorinated Probes to Measure Carboxylesterase Activities Using 19F NMR-Spectroscopy: Application to Erythrocytes and Helicobacter pylori

Eight fluorinated compounds were tested as putative probes to measure carboxylesterase activity employing 19F nuclear magnetic resonance spectroscopy. The method takes advantage of the sensitivity of fluorine resonances to the changes in the chemical bonding in the covalent structures where they are located. Determination of the kinetic parameters of ethyl fluoroacetate and diethyl fluoromalonate in hemolysates showed that these probes were well suited to study carboxylesterase activities in complex systems. the potential of these probes for noninvasive applications was demonstrated in measurements of carboxylesterase kinetic parameters in intact erythrocytes. The presence of carboxylesterases was established in several strains of the bacterium Helicobacter pylori employing 19F nuclear magnetic resonance spectroscopy, and the kinetic parameters of these enzymes for ethyl fluoroacetate and diethyl fluoromalonate were measured.