Post-translational processing, metabolic stability and catalytic efficiency of oat arginine decarboxylase expressed in Trypanosoma cruzi epimastigotes
Trypanosoma cruzi epimastigotes are auxotrophic for polyamines because they are unable to synthesize putrescine de novo. This deficiency is due to the absence of ornithine and arginine decarboxylase genes in the parasite genome. We have been able to obtain transgenic T. cruzi expressing heterologous...
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| Autores principales: | , , |
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2009
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00144894_v122_n3_p169_Serra http://hdl.handle.net/20.500.12110/paper_00144894_v122_n3_p169_Serra |
| Aporte de: |
| Sumario: | Trypanosoma cruzi epimastigotes are auxotrophic for polyamines because they are unable to synthesize putrescine de novo. This deficiency is due to the absence of ornithine and arginine decarboxylase genes in the parasite genome. We have been able to obtain transgenic T. cruzi expressing heterologous genes coding for these enzymes. Since arginine decarboxylase normal expression in oat requires a post-translational proteolytic cleavage of an enzyme precursor, we have investigated whether a similar processing occurs inside the transformed protozoa expressing oat arginine decarboxylase or the same enzyme attached to a C-terminal (his)6-tag. We were able to demonstrate that the post-translational processing also takes place inside the transgenic parasites. This cleavage is probably the result of a general proteolytic activity of T. cruzi acting on a protease-sensitive region of the protein. Interestingly, the (his)6-tagged enzyme expressed in the transformed parasites showed considerably increased metabolic stability and catalytic efficiency. © 2008 Elsevier Inc. All rights reserved. |
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