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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The Non-Canonical Substrates of Trypanosoma cruzi Tyrosine and Aspartate Aminotransferases: Branched-Chain Amino Acids

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Author(s):
Manchola, Nubia Carolina [1] ; Silber, Ariel Mariano [1] ; Nowicki, Cristina [2]
Total Authors: 3
Affiliation:
[1] Univ Sao Paulo, Inst Ciencias Biomed, Lab Biochem Tryps LaBTryps, Ave Prof Lineu Prestes 1374, Sao Paulo - Brazil
[2] Univ Buenos Aires, Fac Farm & Bioquim, CONICET, IQUIFIB, Junin 956, RA-1113 Buenos Aires, DF - Argentina
Total Affiliations: 2
Document type: Journal article
Source: Journal of Eukaryotic Microbiology; v. 65, n. 1, p. 70-76, JAN-FEB 2018.
Web of Science Citations: 2
Abstract

Trypanosoma cruzi, the etiological agent of Chagas disease, lacks genes that encode canonical branched-chain aminotransferases. However, early studies showed that when epimastigotes were grown in the presence of C-14(1)-DL-leucine, the label was incorporated into various intermediates. More recently, our studies provided evidence that T.cruzi epimastigotes display a single ATP-dependent and saturable transport system that enables epimastigotes to uptake branched-chain amino acids (BCAAs) from the culture media. To extend our knowledge of the first step of BCAA catabolism, the ability of this parasite's noncanonical broad specificity aminotransferases, such as tyrosine aminotransferase (TAT) and aspartate aminotransferase (ASAT), to transaminate these amino acids was investigated. Indeed, our results show that TAT and ASAT utilize BCAAs as substrates; however, both enzymes differ in their catalytic competence in utilizing these amino donors. For instance, ASAT transaminates isoleucine nearly 10-fold more efficiently than does TAT. This unique characteristic of TAT and ASAT allows to explain how BCAAs can be oxidized in the absence of a BCAA transaminase in T. cruzi. (AU)

FAPESP's process: 13/18970-6 - Characterization of the Disulfiram effect in Trypanosoma cruzi
Grantee:Ariel Mariano Silber
Support Opportunities: Regular Research Grants
FAPESP's process: 16/06034-2 - The biological role of amino acids and their metabolites in Trypanosoma cruzi
Grantee:Ariel Mariano Silber
Support Opportunities: Research Projects - Thematic Grants