In-solution behavior and protective potential of asparagine synthetase A from Trypanosoma cruzi

• Published in: Molecular and biochemical parasitology 2019-06, Vol.230, p.1-7
• Main Authors: Souza Morini, Flávia, de Castro, Emanuella, de Morais, Stephanie Bath, Lancheros Contreras, Cesar, Pereira Weiler, Ana Valéria, Murakami, Mario Tyago, Pinge-Filho, Phileno, Yamada-Ogatta, Sueli Fumie, de Arruda Campos Brasil de Souza, Tatiana
• Format: Article
• Language: English
• Subjects: Ammonia - metabolism; Animals; Asparagine - metabolism; Asparagine synthetase A; Aspartate-Ammonia Ligase - chemistry; Aspartate-Ammonia Ligase - immunology; Aspartate-Ammonia Ligase - isolation & purification; Aspartate-Ammonia Ligase - metabolism; Chagas Disease - prevention & control; Chromatography, Liquid; Circular Dichroism; Disease Models, Animal; Dynamic Light Scattering; Glutamine - metabolism; Immunoprotection; In-solution behavior; Mice, Inbred BALB C; Parasitemia - prevention & control; Protein Conformation; Protein Folding; Protozoan Vaccines - administration & dosage; Recombinant Proteins - chemistry; Recombinant Proteins - immunology; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; Trypanosoma cruzi; Trypanosoma cruzi - enzymology; Vaccines, Synthetic - administration & dosage
• ISSN: 0166-6851; 1872-9428
• DOI: 10.1016/j.molbiopara.2019.03.002

•Recombinant Tc-AS-A is dimeric and stable in acidic environments.•Our structural inspection showed that Tc-AS-A has the same fold and quaternary arrangement as prokaryotic AS-A.•Immunization with Tc-AS-A confers protection to infective forms of T. cruzi.•Tc-AS-A immunization hampered red blood cell lysis in early infection.•Tc-AS-A immunization reduced the number of platelets and leukocytes. l-Asparagine synthetase (AS) acts in asparagine formation and can be classified into two families: AS-A or AS-B. AS-A is mainly found in prokaryotes and can synthetize asparagine from ammonia. Distinct from other eukaryotes, Trypanosoma cruzi produces an AS-A. AS-A from Trypanosoma cruzi (Tc-AS-A) differs from prokaryotic AS-A due to its ability to catalyze asparagine synthesis using both glutamine and ammonia as nitrogen sources. Regarding these peculiarities, this work uses several biophysical techniques to provide data concerning the Tc-AS-A in-solution behavior. Tc-AS-A was produced as a recombinant and purified by three chromatography steps. Circular dichroism, dynamic light scattering, and analytical size exclusion chromatography showed that Tc-AS-A has the same fold and quaternary arrangement of prokaryotic AS-A. Despite the tendency of protein to aggregate, stable dimers were obtained when solubilization occurred at pH ≤ 7.0. We also demonstrate the protective efficacy against T. cruzi infection in mice immunized with Tc-AS-A. Our results indicate that immunization with Tc-AS-A might confer partial protection to infective forms of T. cruzi in this particular model.