TRANS-SIALIDASE FROM TRYPANOSOMA-CRUZI EPIMASTIGOTES IS EXPRESSED AT the STATIONARY-PHASE and IS DIFFERENT FROM the ENZYME EXPRESSED in TRYPOMASTIGOTES

TRANS-SIALIDASE FROM TRYPANOSOMA-CRUZI EPIMASTIGOTES IS EXPRESSED AT the STATIONARY-PHASE and IS DIFFERENT FROM the ENZYME EXPRESSED in TRYPOMASTIGOTES

Autor Chaves, L. B. Google Scholar
Briones, MRS Google Scholar
Schenkman, S. Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Resumo We have studied the trans-sialidase from insect forms of Trypanosoma cruzi growing in axenic culture. Log phase epimastigotes expressed little or-no trans-sialidase activity, and were unable to incorporate exogenous sialic acid. Trans-sialidase started to be expressed at the late logarithmic phase, with specific activity increasing steadily as the culture reached the stationary phase. Trans-sialidase was purified from the late log phase epimastigote culture, which contained less than 2% of metacyclic forms, yielding a glycoprotein that migrated as a single 90-kDa band in sodium dodecyl sulfate gels. This enzyme features: (1) no reaction with antibodies against the peptide repeats present in the carboxy-terminal of trypomastigote trans-sialidase; (2) positive reaction with antibodies raised against a fragment of trypomastigote trans-sialidase that contains the active site; (3) similar kinetic properties and identical acceptor-donor specificity when compared to the trypomastigote enzyme; and (4) neuraminidase activity in the absence of acceptors. Upon differentiation into metacyclic forms, a trans-sialidase activity containing the carboxy-terminal repeats of the trypomastigote enzyme was released into the medium. These results suggest that epimastigotes express a developmentally regulated trans-sialidase that contains the same catalytic site but lacks the tandem amino acid repeats typical of trypomastigote trans-sialidase.
Palavra-chave TRYPANOSOMA-CRUZI
TRANS-SIALIDASE
SIALIC ACID
PURIFICATION
ANTIGENIC SITE
Idioma Inglês
Data de publicação 1993-09-01
Publicado em Molecular and Biochemical Parasitology. Amsterdam: Elsevier B.V., v. 61, n. 1, p. 97-106, 1993.
ISSN 0166-6851 (Sherpa/Romeo, fator de impacto)
Publicador Elsevier B.V.
Extensão 97-106
Fonte http://dx.doi.org/10.1016/0166-6851(93)90162-Q
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:A1993LZ79600010
Endereço permanente http://repositorio.unifesp.br/handle/11600/25352

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