Mycobacterium tuberculosis (Mtb) purine nucleoside phosphorylase (PNP, EC 184.108.40.206) has been identified as a target for the development of specific inhibitors with potential antimycobacterial activity.We hereby described the development and validation of a new 96-well LC-ESI-MS/MS method to assess the inhibition activity of nucleoside analogues towards MtbPNP and the human PNP (HsPNP). Enzyme activity was determined by monitoring the phosphorolysis of inosine (Ino) to hypoxanthine (Hpx). The enzymatic assay (v ¼ 0.5 mL, enzyme<0.2 mg/well, T ¼ 37 C) was performed with an overall time of about 15 min/plate for sample processing and 2 min/sample for LC-MS analysis. Validation of the quantification method met the criteria of the CDER guidance of FDA. Kinetic parameters were in agreement with those reported in literature (HsPNP KM ¼ 0.150 ± 0.020 mM vs 0.133 ± 0.015 mM; MtbPNP KM ¼ 0.060 ± 0.009 mM vs 0.040 ± 0.003 mM for Ino), thus demonstrating the reliability of the newly developed enzymatic assay. Preliminary inhibition assays confirmed the effects reported for Acyclovir (Acv) and Formycin A (FA) against HsPNP and MtbPNP. The validated enzymatic assay was applied to the evaluation of a set of 8-halo-, 8-amino-, 8-O-alkyl-substituted purine ribonucleosides synthesized on purpose as potential inhibitors against MtbPNP. The assayed 8-substituted ribonucleosides did not exert a significant inhibitory effect against the tested enzymes up to 1 mM.
Development, validation and application of a 96-well enzymatic assay based on LC-ESI-MS/MS quantification for the screening of selective inhibitors against Mycobacterium tuberculosis purine nucleoside phosphorylase / G. Cattaneo, D. Ubiali, E. Calleri, M. Rabuffetti, G. C. Höfner, K. T. Wanner, M.C. De Moraes, L. K. B. Martinelli, D. Santiago Santos, G. Speranza, G. Massolini. - In: ANALYTICA CHIMICA ACTA. - ISSN 0003-2670. - 943(2016), pp. 89-97.
|Titolo:||Development, validation and application of a 96-well enzymatic assay based on LC-ESI-MS/MS quantification for the screening of selective inhibitors against Mycobacterium tuberculosis purine nucleoside phosphorylase|
SPERANZA, GIOVANNA (Penultimo)
|Parole Chiave:||Mycobacterium tuberculosis; purine nucleoside phosphorylase; Human purine nucleoside phosphorylase; Enzyme inhibition; LC-ESI-MS/MS assay; 96-Well enzymatic assay; 8-Substituted purine ribonucleosides|
|Settore Scientifico Disciplinare:||Settore CHIM/06 - Chimica Organica|
Settore CHIM/08 - Chimica Farmaceutica
|Data di pubblicazione:||2016|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.aca.2016.09.025|
|Appare nelle tipologie:||01 - Articolo su periodico|