In vitro and in vivo characterization of the multiple isoforms of Schistosoma mansoni Hypoxanthine-guanine phosphoribosyltransferases

Publication date: Available online 14 February 2019Source: Molecular and Biochemical ParasitologyAuthor(s): Larissa Romanello, Ana Eliza Zeraik, Adriano de Freitas Fernandes, Juliana Roberta Torini, Louise E. Bird, Joanne E. Nettleship, Heather Rada, Yamini Reddivari, Ray J. Owens, Vitor Hugo Balasco Serrão, Ricardo DeMarco, José Brandão-Neto, Humberto D'Muniz PereiraAbstractSchistosoma mansoni, the parasite responsible for schistosomiasis, lacks the “de novo” purine biosynthetic pathway and depends entirely on the purine salvage pathway for the supply of purines. Numerous reports of praziquantel resistance have been described, as well as stimulated efforts to develop new drugs against schistosomiasis. Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is a key enzyme of the purine salvage pathway. Here, we describe a crystallographic structure of the S. mansoni HPGRT-1 (SmHGPRT), complexed with IMP at a resolution of 2.8Ǻ. Four substitutions were identified in the region of the active site between SmHGPRT-1 and human HGPRT. We also present data from RNA-Seq and WISH, suggesting that some isoforms of HGPRT might be involved in the process related to sexual maturation and reproduction in worms; furthermore, its enzymatic assays show that the isoform SmHGPRT-3 does not present the same catalytic efficiency as other isoforms. Finally, although other studies have previously suggested this enzyme as a potential antischistosomal chemotherapy target, the kinetics paramet...
Source: Molecular and Biochemical Parasitology - Category: Parasitology Source Type: research