scholarly journals Biochemical and genetic characterization of Trypanosoma cruzi N-myristoyltransferase

2014 ◽  
Vol 459 (2) ◽  
pp. 323-332 ◽  
Author(s):  
Adam J. Roberts ◽  
Leah S. Torrie ◽  
Susan Wyllie ◽  
Alan H. Fairlamb
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Genetic Characterization ◽  
Kinetic Properties

The present study shows that N-myristoyltransferase is essential for growth of Trypanosoma cruzi, the parasite responsible for Chagas’ disease. The kinetic properties of the enzyme are described along with evidence that growth is specifically inhibited by blocking N-myristoylation in the parasite.

scholarly journals Genetic Characterization of Trypanosoma cruzi Directly from Tissues of Patients with Chronic Chagas Disease

2000 ◽  
Vol 156 (5) ◽  
pp. 1805-1809 ◽  
Author(s):  
Annamaria R. Vago ◽  
Luciana O. Andrade ◽  
Adriana A. Leite ◽  
Débora d'Ávila Reis ◽  
Andrea M. Macedo ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Genetic Characterization ◽  
Chronic Chagas Disease

scholarly journals Ribose 5-phosphate isomerase type B from Trypanosoma cruzi: kinetic properties and site-directed mutagenesis reveal information about the reaction mechanism

2006 ◽  
Vol 401 (1) ◽  
pp. 279-285 ◽  
Author(s):  
Ana L. Stern ◽  
Emmanuel Burgos ◽  
Laurent Salmon ◽  
Juan J. Cazzulo
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Pentose Phosphate ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Kinetic Properties ◽  
Type B ◽  
Nucleotide Synthesis ◽  
Gene Coding ◽  
Genes Encoding

Trypanosoma cruzi, the human parasite that causes Chagas disease, contains a functional pentose phosphate pathway, probably essential for protection against oxidative stress and also for R5P (ribose 5-phosphate) production for nucleotide synthesis. The haploid genome of the CL Brener clone of the parasite contains one gene coding for a Type B Rpi (ribose 5-phosphate isomerase), but genes encoding Type A Rpis, most frequent in eukaryotes, seem to be absent. The RpiB enzyme was expressed in Escherichia coli as a poly-His tagged active dimeric protein, which catalyses the reversible isomerization of R5P to Ru5P (ribulose 5-phos-phate) with Km values of 4 mM (R5P) and 1.4 mM (Ru5P).4-Phospho-D-erythronohydroxamic acid, an analogue to the reaction intermediate when the Rpi acts via a mechanism involving the formation of a 1,2-cis-enediol, inhibited the enzyme competi-tively, with an IC50 value of 0.7 mM and a Ki of 1.2 mM. Site-directed mutagenesis allowed the demonstration of a role for His102, but not for His138, in the opening of the ribose furanosic ring. A major role in catalysis was confirmed for Cys69, since the C69A mutant was inactive in both forward and reverse directions of the reaction. The present paper contributes to the know-ledge of the mechanism of the Rpi reaction; in addition, the absence of RpiBs in the genomes of higher animals makes this enzyme a possible target for chemotherapy of Chagas disease.

scholarly journals Characterization of Trypanosoma cruzi Sirtuins as Possible Drug Targets for Chagas Disease

2015 ◽  
Vol 59 (8) ◽  
pp. 4669-4679 ◽  
Author(s):  
Nilmar Silvio Moretti ◽  
Leonardo da Silva Augusto ◽  
Tatiana Mordente Clemente ◽  
Raysa Paes Pinto Antunes ◽  
Nobuko Yoshida ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Drug Targets ◽  
Wild Type ◽  
Content Type ◽  
Damage Repair ◽  
Lysine Deacetylases

ABSTRACTAcetylation of lysine is a major posttranslational modification of proteins and is catalyzed by lysine acetyltransferases, while lysine deacetylases remove acetyl groups. Among the deacetylases, the sirtuins are NAD+-dependent enzymes, which modulate gene silencing, DNA damage repair, and several metabolic processes. As sirtuin-specific inhibitors have been proposed as drugs for inhibiting the proliferation of tumor cells, in this study, we investigated the role of these inhibitors in the growth and differentiation ofTrypanosoma cruzi, the agent of Chagas disease. We found that the use of salermide during parasite infection prevented growth and initial multiplication after mammalian cell invasion byT. cruziat concentrations that did not affect host cell viability. In addition,in vivoinfection was partially controlled upon administration of salermide. There are two sirtuins inT. cruzi, TcSir2rp1 and TcSir2rp3. By using specific antibodies and cell lines overexpressing the tagged versions of these enzymes, we found that TcSir2rp1 is localized in the cytosol and TcSir2rp3 in the mitochondrion. TcSir2rp1 overexpression acts to impair parasite growth and differentiation, whereas the wild-type version of TcSir2rp3 and not an enzyme mutated in the active site improves both. The effects observed with TcSir2rp3 were fully reverted by adding salermide, which inhibited TcSir2rp3 expressed inEscherichia coliwith a 50% inhibitory concentration (IC50) ± standard error of 1 ± 0.5 μM. We concluded that sirtuin inhibitors targeting TcSir2rp3 could be used in Chagas disease chemotherapy.

scholarly journals Molecular characterization of Trypanosoma cruzi Mexican strains and their behavior in the mouse experimental model

2011 ◽  
Vol 44 (6) ◽  
pp. 684-690 ◽  
Author(s):  
César Gómez-Hernández ◽  
Karine Rezende-Oliveira ◽  
Gabriel Antônio Nogueira Nascentes ◽  
Lara Rocha Batista ◽  
Henrique Borges Kappel ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Random Amplified Polymorphic Dna ◽  
Geographic Origin ◽  
Pcr Amplification ◽  
Biological Characterization ◽  
Long Time ◽  
Intergenic Regions ◽  
Mexican Strains

INTRODUCTION: For a long time, the importance of Chagas disease in Mexico, where many regarded it as an exotic malady, was questioned. Considering the great genetic diversity among isolates of Trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of Chagas disease in Mexico, this study aimed to identify the molecular and biological characterization of Trypanosoma cruzi isolates from different endemic areas of this country, especially of the State of Jalisco. METHODS: Eight Mexican Trypanosoma cruzi strains were biologically and genetically characterized (PCR specific for Trypanosoma cruzi, multiplex-PCR, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, RAPD - (random amplified polymorphic DNA). RESULTS: Two profiles of parasitaemia were observed, patent (peak parasitaemia of 4.6×10(6) to 10(7) parasites/mL) and subpatent. In addition, all isolates were able to infect 100% of the animals. The isolates mainly displayed tropism for striated (cardiac and skeletal) muscle. PCR amplification of the mini-exon gene classified the eight strains as TcI. The RAPD technique revealed intraspecies variation among isolates, distinguishing strains isolated from humans and triatomines and according to geographic origin. CONCLUSIONS: The Mexican T. cruzi strains are myotrophic and belong to group TcI.

scholarly journals Trypanosoma cruzi and experimental Chagas' disease: characterization of a stock isolated from a patient with associated digestive and cardiac form

1993 ◽  
Vol 26 (1) ◽  
pp. 25-33 ◽  
Author(s):  
E.C. Oliveira ◽  
M.M.A. Stefani ◽  
A.O. Luquetti ◽  
E.F. Vêncio ◽  
M.A.R. Moreira ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Digestive Tract ◽  
Chagas Disease ◽  
Acute Phase ◽  
Experimental Infection ◽  
Post Infection ◽  
Chronic Phase ◽  
Igg Antibodies ◽  
Histopathology Examination

A new Trypanosoma cruzi stock isolated from a patient in the chronic phase of Chagas' disease with the digestive and cardiac fortn of the disease was characterized by experimental infection in isogenic, susceptible, A/Sn strain mice. Parasitemia curves showed up to 1.7x10(6) parasites/ml and no mortality was observed up to 300 days post infection. Specific IgM was found in mice in the acute phase up to 40 days and also in the chronic phase. IgG antibodies yvere detected in the acute and chronic phase. Histopathology examination demonstrated myotropism to the digestive tract muscle layers and to the heart.

Characterization of human infection by Leishmania spp. in the Northwest of Argentina: immune response, double infection with Trypanosoma cruzi and species of Leishmania involved

Parasitology ◽  
2003 ◽  
Vol 126 (1) ◽  
pp. 31-39 ◽  
Author(s):  
F. M. FRANK ◽  
M. M. FERNÁNDEZ ◽  
N. J. TARANTO ◽  
S. P. CAJAL ◽  
R. A. MARGNI ◽  
...  
Keyword(s):  
Immune Response ◽  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Human Infection ◽  
Double Infection ◽  
Strong Immune Response ◽  
American Tegumentary Leishmaniasis ◽  
Leishmania Spp ◽  
Very High

The aims of this study were to characterize human American tegumentary leishmaniasis, which includes cutaneous, mucocutaneous and mucosal leishmaniasis, in Northwest Argentina, to determine the prevalence of double infection with Trypanosoma cruzi and to identify the species of Leishmania in this area. Most of the 330 leishmaniasis patients presented cutaneous ulcers (96·1%), 2·4% mucocutaneous and 1·5% the mucosal form (‘espundia’). The aetiological agents, determined by isoenzyme electrophoresis, were identified as Leishmania (Viannia) braziliensis in 16 out of 20 isolates and in the remaining 4 as Leishmania (Leishmania) amazonensis, the first ever-documented in Argentina. Sera analysed by ELISA and IFA using complex antigen from both T. cruzi and L. braziliensis showed a very high percentage of positives (66·3–78·2%). When antigens for specific diagnosis of Chagas' disease were used, 40·9% of the leishmaniasis patients were also found to be infected by T. cruzi. These results indicate that the strong immune response against T. cruzi gave no protection to Leishmania, in spite of the serological cross-reaction between these parasites. In addition, we showed that more than 40% of the patients would be misdiagnosed as chagasic if complex antigens, as epimastigotes or soluble fraction from epimastigotes, were used in IFA or ELISA. This is of paramount importance not only because patients' treatment would be associated to misdiagnosis but the fact that in many countries in Central and South America, a positive test for Chagas' disease means a rejection for those seeking employment.

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