Study of Anopheles gambiae 3-hydroxykynurenine transaminase activity and inhibition by LC-MS/MS method

Publication date: Available online 13 May 2019Source: Journal of Pharmaceutical and Biomedical AnalysisAuthor(s): Rossana Canavesi, Riccardo Miggiano, Martina Stella, Ubaldina Galli, Franca Rossi, Menico Rizzi, Erika Del GrossoAbstractIn Anopheles gambiae, the most efficient vector of the malaria parasite Plasmodium falciparum, 3-hydroxykynurenine is endowed with a toxic potential. In adult mosquitoes, the excess of 3-hydroxykynurenine is removed by a specific transaminase (3-hydroxykynurenine transaminase, HKT) which converts the compound into the more stable xanthurenic acid. Interfering with 3-hydroxykynurenine metabolism in A. gambiae is a potential approach for the development of transmission-blocking drugs and insecticides. Hence, the aims of this work were to develop and validate a new LC-MS/MS method for the evaluation of A. gambiae 3-hydroxykynurenine transaminase (Ag-HKT) activity and the determination of the potency of inhibitors of the enzyme. We set up a LC-MS/MS-based enzymatic assay for the determination of kinetic constants values of the recombinant Ag-HKT enzyme and for the evaluation of Ag-HKT inhibition by a known protein inhibitor used as reference and a newly synthesized compound. The chromatographic separation was performed in a gradient mode on a Phenomenex Synergi Polar-RP (150 × 2.0, 4 µm) with methanol and water containing both 0.2% formic acid. Mass spectrometric detection was achieved with an ion trap equipped with an ESI source, in positiv...
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research