| dc.creator | Giarola, Naira Lígia Lima | |
| dc.creator | Amaral, Elmo Eduardo de Almeida | |
| dc.creator | Collopy Júnior, Itallo | |
| dc.creator | Souza, André Luiz Fonseca de | |
| dc.creator | Majerowicz, David | |
| dc.creator | Paes, Lisvane Silva | |
| dc.creator | Gondim, Katia C. | |
| dc.creator | Fernandes, José Roberto Meyer | |
| dc.date | 2016-08-25T12:10:32Z | |
| dc.date | 2016-08-25T12:10:32Z | |
| dc.date | 2013 | |
| dc.date.accessioned | 2023-09-26T20:47:10Z | |
| dc.date.available | 2023-09-26T20:47:10Z | |
| dc.identifier | GIAROLA, Naíra Lígia Lima; et al. Trypanosoma cruzi: Effects of heat shock on ecto-ATPase activity. Experimental Parasitology, v.133, n.4, p.434-441, Apr. 2013. | |
| dc.identifier | 0014-4894 | |
| dc.identifier | https://www.arca.fiocruz.br/handle/icict/15386 | |
| dc.identifier | 10.1016/j.exppara.2012.12.014 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/8863856 | |
| dc.description | In this work, we demonstrate that Trypanosoma cruzi Y strain epimastigotes exhibit Mg2+-dependent ecto-ATPase activity that is stimulated by heat shock. When the epimastigotes were incubated at 37°C for 2h, the ecto-ATPase activity of the cells was 43.95±0.97 nmol Pi/h×10(7) cells, whereas the ecto-ATPase activity of cells that were not exposed to heat shock stress was 16.97±0.30 nmol Pi/h×10(7) cells. The ecto-ATPase activities of cells, that were exposed or not exposed to heat shock stress had approximately the same Km values (2.25±0.26 mM ATP and 1.55±0.23 mM ATP, respectively) and different Vmax values. The heat-shocked cells had higher Vmax values (54.38±3.07 nmol Pi/h×10(7) cells) than the cells that were not exposed to heat shock (19.38±1.76 nmol Pi/h×10(7) cells). We also observed that the ecto-phosphatase and ecto-5'nucleotidase activities of cells that had been incubated at 28°C or 37°C were the same. Interestingly, cycloheximide, an inhibitor of protein synthesis, suppressed the heat shock effect of ecto-ATPase activity on T. cruzi. The Mg2+-dependent ecto-ATPase activity from the Y strain (high virulence) was approximately 2-fold higher than that of Dm28c (a clone with low virulence). In addition, these two strains presented different responses to heat shock with regard to their ecto-ATPase activities; Y strain epimastigotes had a stimulation of 2.52-fold while the Dm28c strain had a 1.71-fold stimulation. In this context, the virulent trypomastigote form of T. cruzi, Dm28c, had an ecto-ATPase activity that was more than 7-fold higher (66.67±5.98 nmol Pi/h×10(7) cells) than that of the insect epimastigote forms (8.91±0.76 nmol Pi/h×10(7) cells). This difference increased to approximately 10-fold when both forms were subjected to heat shock stress (181.14±16.48 nmol Pi/h×10(7) cells for trypomastigotes and 16.71±1.17 nmol Pi/h×10(7) cells for epimastigotes at 37°C). The ecto-ATPase activity of a plasma membrane-enriched fraction obtained from T. cruzi epimastigotes was not increased by heat treatment, which suggested that cytoplasmic components had an influence on enzyme activation by heat shock stress. | |
| dc.description | 2030-01-01 | |
| dc.format | application/pdf | |
| dc.language | eng | |
| dc.publisher | Elsevier | |
| dc.rights | restricted access | |
| dc.subject | Trypanosoma cruzi | |
| dc.subject | Choque térmico | |
| dc.subject | Trypanosoma cruzi | |
| dc.subject | Ecto-ATPase | |
| dc.subject | Heat shock | |
| dc.title | Trypanosoma cruzi: effects of heat shock on ecto-ATPase activity | |
| dc.type | Article | |
