caa a22 4500 477120490 CHVBK 20180405111635.0 cr unu---uuuuu 170330e19961201xx s 000 0 eng 10.1007/BF00229474 doi (NATIONALLICENCE)springer-10.1007/BF00229474 Heart FoF1-ATPase changes during the acute phase of Trypanosoma cruzi infection in rats [Elektronische Daten] [Sérgio Uyemura, Maria Jordani, Ana Polizello, Carlos Curti] The kinetic properties of ATP hydrolysis and synthesis by FoF1-ATPase of heart mitochondria were evaluated during the acute phase of T. cruzi infection in rats. Mitochondria and submitochondrial particles were isolated 7 days (early stage) and 25 days (late stage) following infection of rats with 2 × 105 trypomastigote forms of the Y strain of T. cruzi. The kinetic properties for ATP hydrolysis were altered for the early but not the late stage, showing a changed pH profile, increased K0.5 values, and a decreased total Vmax. The Arrhenius' plot for membrane-associated enzyme showed a higher transition temperature with a lower value for the activation energy in body temperature. For the Triton X-100 - solubilized enzyme, the plot was similar to the control. A decrease in the efficiency of ADP phosphorylation by mitochondria, measured by the firefly-luciferase luminescence, was observed only during the late stage and appeared to be correlated with a decrease in the affinity of the FoF1-ATPase for ADP. It is proposed that in the early stage, during the acute phase of T. cruzi infection in rats, heart FoF1-ATPase undergoes a membrane-dependent conformational change in order to maintain the phosphorylation potential of mitochondria, which would compensate for the uncoupling of mitochondrial function. Also, during both the early and late stages, the enzyme seems to be under the regulation of the endogenous inhibitor protein for the preservation of cellular ATP levels. Kluwer Academic Publishers, 1996 Trypanosoma cruzi nationallicence rat heart nationallicence mitochondria nationallicence oxidative phosphorylation nationallicence FoF1-ATPase nationallicence ATP hydrolysis nationallicence ATP synthesis nationallicence Uyemura Sérgio Department of Clinical, Toxicological and Bromatological Analysis, University of São Paulo, Av. Café, s/n°, 14040-903, Ribeirão Preto, SP, Brasil aut Jordani Maria Department of Physics and Chemistry, School of Pharmaceutical Science, University of São Paulo, Av. Café, s/n°, 14040-903, Ribeirão Preto, SP, Brasil aut Polizello Ana Department of Clinical, Toxicological and Bromatological Analysis, University of São Paulo, Av. Café, s/n°, 14040-903, Ribeirão Preto, SP, Brasil aut Curti Carlos Department of Clinical, Toxicological and Bromatological Analysis, University of São Paulo, Av. Café, s/n°, 14040-903, Ribeirão Preto, SP, Brasil aut Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 165/2(1996-12-01), 127-133 0300-8177 165:2<127 1996 165 11010 https://doi.org/10.1007/BF00229474 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00229474 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Uyemura Sérgio Department of Clinical, Toxicological and Bromatological Analysis, University of São Paulo, Av. Café, s/n°, 14040-903, Ribeirão Preto, SP, Brasil aut NATIONALLICENCE 700 1- Jordani Maria Department of Physics and Chemistry, School of Pharmaceutical Science, University of São Paulo, Av. Café, s/n°, 14040-903, Ribeirão Preto, SP, Brasil aut NATIONALLICENCE 700 1- Polizello Ana Department of Clinical, Toxicological and Bromatological Analysis, University of São Paulo, Av. Café, s/n°, 14040-903, Ribeirão Preto, SP, Brasil aut NATIONALLICENCE 700 1- Curti Carlos Department of Clinical, Toxicological and Bromatological Analysis, University of São Paulo, Av. Café, s/n°, 14040-903, Ribeirão Preto, SP, Brasil aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 165/2(1996-12-01), 127-133 0300-8177 165:2<127 1996 165 11010 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer