Immobilized purine nucleoside phosphorylase from Schistosoma mansoni for specific inhibition studies

Autor(es)

de Moraes, Marcela Cristina ^[1] ; Cardoso, Carmen L. ^[2] ; Cass, Quezia B. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Quim, BR-13565905 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ANALYTICAL AND BIOANALYTICAL CHEMISTRY; v. 405, n. 14, p. 4871-4878, MAY 2013.
• Citações Web of Science: 14

Resumo

The parasite Schistosoma mansoni (Sm) depends exclusively on the salvage pathway for its purine requirements. The enzyme purine nucleoside phosphorylase (PNP) is, therefore, a promising target for development of antischistosomal agents and an assay for screening of inhibitors. To enable this, immobilized SmPNP reactors were produced. By quantification of hypoxanthine by liquid chromatography, kinetic constants (K (M)) for the substrate inosine were determined for the free and immobilized enzyme as 110 +/- 6.90 mu mol L (-1) and 164 +/- 13.4 mu mol L (-1) , respectively, indicating that immobilization did not affect enzyme activity. Furthermore, the enzyme retained 25 % of its activity after four months. Non-Michaelis kinetics for the phosphate substrate, and capacity for P-i-independent hydrolysis were also demonstrated, despite the low rate of enzymatic catalysis. Use of an SmPNP immobilized enzyme reactor (IMER) for inhibitor-screening assays was demonstrated with a small library of 9-deazaguanine analogues. The method had high selectivity and specificity compared with screening by use of the free enzyme by the Kalckar method, and furnished results without the need for verification of the absence of false positives. (AU)

• Processo FAPESP: 08/04051-0 - Desenvolvimento e aplicação de biorreatores capilares para a triagem de inibidores da Purina Nucleosídeo Fosforilase
• Beneficiário: Marcela Cristina de Moraes
• Modalidade de apoio: Bolsas no Brasil - Doutorado