Disease relevance of Tc00.1047053510901.90

• This work describes the identification, expression, purification, enzyme kinetics, and the role of divalent metal in the ATPase activity of the RNA triphosphatase from Trypanosoma cruzi, the agent of Chagas' disease, and compares it with the previously characterized enzyme from Trypanosoma brucei [1].

High impact information on Tc00.1047053510901.90

• ATPase activity in plasma membrane from TcHA1- and (N-terminal truncated) TcHA2-transfected yeast was inhibited to different extents by vanadate, whereas the latter yeast strain was more resistant to extremes of pH, suggesting that the native proteins may serve different functions at different stages in the T. cruzi life cycle [2].
• Finally, the specific activity of the Mg(2+)-dependent, vanadate-sensitive ATPase present in the membranes was also inhibited by ca. 50% in SBI-treated cells [3].
• Based on enzyme kinetics, circular dichroism, and intrinsic fluorescence analysis, a kinetic mechanism for the ATPase activity of the T. cruzi tunnel triphosphatase is proposed [1].
• In contrast, ouabain, an (Na++/K+) ATPase inhibitor, did not affect transport [4].
• Crystal violet released respiratory control, and enhanced ATPase activity of digitonin-permeabilized epimastigotes [5].

Biological context of Tc00.1047053510901.90

• ATP hydrolysis by Crithidia fasciculata mitochondrial ATPase was studied through the use of submitochondrial particles and the soluble enzyme [6].

Anatomical context of Tc00.1047053510901.90

• Succinate dehydrogenase and sn-glycerol-3-phosphate dehydrogenase, together with oligomycin-sensitive ATPase, were located in the mitochondrion which had a density in sucrose ranging from 1.16 to 1.18 g/cm3 [7].
• We have previously shown that Ca2+ ATPase of the sarcoplasmic reticulum (SERCA) is involved in the invasion of T. cruzi in cardiomyocytes [8].
• (c) When polyamines were present throughout the preparation of the mitochondrial membranes, the membrane-bound ATPase was irreversibly inactivated [6].
• One of them is the acidocalcisome, cytoplasmic vacuoles containing a very high Ca2+ concentration and a Ca2+ - H+ translocating ATPase activity, present in all trypanosomatids [9].
• 1. Subcellular fractions obtained from epimastigotes of Trypanosoma cruzi, disrupted by three different procedures, contained in addition to the already known Mg2+-activated adenosine triphosphatase (ATPase; E.C.3.6.1.4), a Ca2+-ATPase activity [10].

Associations of Tc00.1047053510901.90 with chemical compounds

• The reaction of Trypanosoma cruzi Mg2+-stimulated adenosine triphosphatase (ATPase, coupling factor 1, or F1) with phenylglyoxal, a dicarbonylic compound, resulted in a rapid loss of its enzymatic activity [11].
• Steady-state velocity studies using a substrate regenerating system showed that efrapeptin, citreoviridin and aurovertin inhibit both membrane-bound and soluble mitochondrial ATPase (coupling factor F1) from Trypanosoma cruzi [12].
• To confirm that this Mg-dependent ATPase was an ecto-ATPase, we used an impermeant inhibitor, DIDS (4, 4'.diisothiocyanostylbene 2'-2'-disulfonic acid) as well as suramin, an antagonist of P2 purinoreceptors and inhibitor of some ecto-ATPases [13].
• Since phenylglyoxal reacts with arginyl residues at the ATPase hydrolytic site, these results suggest that the oxgen-sensitive thiols were located outside the hydrolytic site [14].
• (b) The ATPase activity inhibited by spermine was partially recovered when excess Mg2+ was added to the reaction mixture [6].

Other interactions of Tc00.1047053510901.90

• The membranes form closed vesicles of 0.2-0.4 micron in diameter which display Mg2+ ATPase and acid phosphatase activities, but are devoid of 5'-nucleotidase and succinate-cytochrome c oxidoreductase; these vesicles can be strongly agglutinated by concanavalin A [15].

Analytical, diagnostic and therapeutic context of Tc00.1047053510901.90

• An inhibitor of Crithidia fasciculata and Trypanosoma cruzi H+ -ATP synthase (ATPase) was isolated from these organims mitochondrial particles, either by (a) ammonium sulfate-cholate extraction followed by heat treatment and ethanol precipitation, or (b) gel-filtration on Sephadex G-50, followed by a similar purification procedure [16].

References