A SIALIDASE ACTIVITY in the MIDGUT of the INSECT TRIATOMA-INFESTANS IS RESPONSIBLE for the LOW-LEVELS of SIALIC-ACID in TRYPANOSOMA-CRUZI GROWING in the INSECT VECTOR

A SIALIDASE ACTIVITY in the MIDGUT of the INSECT TRIATOMA-INFESTANS IS RESPONSIBLE for the LOW-LEVELS of SIALIC-ACID in TRYPANOSOMA-CRUZI GROWING in the INSECT VECTOR

Autor Amino, R. Google Scholar
Serrano, A. A. Google Scholar
Morita, O. M. Google Scholar
Pereirachioccola, V. L. Google Scholar
Schenkman, S. Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
INST DANTE PAZZANESE CARDIOL
Resumo Trypanosoma cruzi expresses a unique trans-sialidase that is responsible for the transfer of sialic acid from host glycoproteins and glycolipids to mucin-like glycoprotein accepters on the parasite surface, the enzyme and the sialic acid accepters are present in the mammalian forms of the parasite and in the parasite forms that grow in axenic cultures, which correspond to the developmental stages found in the insect vectors. Here we show that parasite forms growing in the vector Triatoma infestans express trans-sialidase in the hindgut portions of the insect, However, the sialic acid accepters are poorly sialylated due to the low concentration of sialic acid donors in the gut lumen of T.infestans, which feeds exclusively on blood that is rich in sialic acid donors, These low levels of sialic acid donors are due to a novel sialidase activity present mainly in the anterior midgut with high specificity for alpha-2,3-sialyllactose, but not for alpha-2,6-sialyl-lactose, the activity is present in starved insects or insects fed with culture medium, indicating that it did not originate from the blood meal, Enzyme activity does not decrease in insects fed with antibiotics, is present in the salivary glands, and the few bacteria isolated from the gut and faeces of T.infestans did not display sialidase activity, indicating that the enzyme is not derived from a commensal organism, This novel activity could have a nutritional role in the gut of haematophagous insects and indicates that acquisiton of sialic acid is not required for parasite development in the gut of T.infestans.
Palavra-chave INSECT
SIALIC ACID
SIALIDASE
TRYPANOSOMA CRUZI
Idioma Inglês
Data de publicação 1995-09-01
Publicado em Glycobiology. Oxford: Oxford Univ Press United Kingdom, v. 5, n. 6, p. 625-631, 1995.
ISSN 0959-6658 (Sherpa/Romeo, fator de impacto)
Publicador Oxford Univ Press United Kingdom
Extensão 625-631
Fonte http://dx.doi.org/10.1093/glycob/5.6.625
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:A1995RZ73000010
Endereço permanente http://repositorio.unifesp.br/handle/11600/25526

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