Label-free assay based on immobilized capillary enzyme reactor of Leishmania infantum nucleoside triphosphate diphosphohydrolase (LicNTPDase-2-ICER-LC/UV)

• Autor(a) principal: Vasconcellos, Raphael de Souza
• Data de Publicação: 2016
• Outros Autores: Magalhães, Luana, Oliveira, Arthur Henrique Cavalcante de, Mariotini-Moura, Christiane, Firmino, Rafaela de Cássia, Fietto, Juliana Lopes Rangel, Cardoso, Carmen Lúcia
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1016/j.jchromb.2015.11.028; http://www.locus.ufv.br/handle/123456789/21772
• topic: Nucleoside triphosphate diphosphohydrolase; NTPDase-2; Leishmania infantum; Enzyme; Immobilization; Multidimensional enzymatic assay

Nucleoside triphosphate diphosphohydrolase (NTPDase) is an enzyme belonging to the apyrase family that participates in the hydrolysis of the nucleosides di- and triphosphate to the corresponding nucleoside monophosphate. This enzyme underlies the virulence of parasites such as Leishmania. Recently, an NTPDase from Leishmania infantum (LicNTPDase-2) was cloned and expressed and has been considered as a new drug target for the treatment of leishmaniasis. With the intent of developing label-free online screening methodologies, LicNTPDase-2 was covalently immobilized onto a fused silica capillary tube in the present study to create an immobilized capillary enzyme reactor (ICER) based on LicNTPDase-2 (LicNTPDase-2-ICER). To perform the activity assays, a multidimensional chromatographic method was developed employing the LicNTPDase-2-ICER in the first dimension, and an analytical Ascentis C8 column was used in the second dimension to provide analytical separation of the substrates and products. The validated LicNTPDase-2-ICER method provided the following kinetic parameters of the immobilized enzyme: KM of 2.2 and 1.8 mmol L^−1 for the ADP and ATP substrates, respectively. Suramin (1 mmol L^−1) was also shown to inhibit 32.9% of the enzymatic activity. The developed method is applicable to kinetic studies and enables the recognition of the ligands. Furthermore, a comparison of the values of LicNTPDase-2-ICER with those obtained with an LC method using free enzyme in solution showed that LicNTPDase-2-ICER-LC/UV was an accurate and reproducible method that enabled automated measurements for the rapid screening of ligands.