Novel cysteine proteinase in Trypanosoma cruzi metacyclogenesis

• Autores: Duschak, Vilma G; Barboza, M; Garcia, G. A.; Lammel, Estela M.; Couto, Alicia S; Isola, E L D
• Año de publicación: 2006
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Parasitology 2006;132(Pt 3):345-355
• Materia: Trypanosoma cruzi; Proteasas de Cisteína; Enfermedad de Chagas
• Institución: Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"

Fil: Duschak, Vilma G. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.
Fil: Barboza, M. Universidad Nacional de General San Martín. Instituto de Investigaciones Biotecnológicas–INTECH; Argentina.
Fil: Garcia, G. A. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.
Fil: Lammel, Estela M. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología, Parasitología e Inmunología; Argentina.
Fil: Couto, Alicia S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica. CIHIDECAR; Argentina.
Fil: Isola, E. L. D. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología, Parasitología e Inmunología; Argentina.
With the aim to study proteinases released to the culture medium during Trypanosoma cruzi metacyclogenesis, the presence of cysteine proteinases (CPs) was analysed in culture supernatants obtained throughout the differentiation induced by stimulation of epimastigotes with Triatoma infestans hindgut homogenate. In SDS-gelatin containing gels, an important endopeptidase activity with apparent molecular weight range between 97 and 116 kDa was encountered at pH 6, which was abolished by the specific cysteine proteinase inhibitor E-64 and TLCK, but not by pepstatin, 1,10 phenantroline or PMSF. This novel CP, named TcCPmet, showed affinity to cystatin-Sepharose, denoting its thiol-proteinase character as well as to ConA-Sepharose, indicating it contains N-linked oligosaccharides. However, it presented a different elution pattern on ConA-Sepharose than cruzipain and, in addition, it was not recognized by anti-cruzipain serum, facts that strongly suggest the different nature of both CPs. Moroever, evidence is presented indicating that TcCPmet was able to hydrolyse the same chromogenic peptides as cruzipain at optimal alkaline pH values, although with a different order of effectiveness. Our results indicate the presence of a novel CP secreted by metacyclic trypomastigotes and reinforces the important role of these enzymes in metacyclogenesis.