Trans-sialidase and neuraminidase activities have been detected on the surface membrane of trypomastigotes of Trypanosoma cruzi, and both have been implicated in the parasite's invasion of host cells. We show here that these enzymes are structurally related. They are recognized by two independently derived monoclonal antibodies, are anchored to the membrane by glycosylphosphatidylinositol, copurify by ion exchange, molecular sieving, and hydrophobic chromatography, have maximal activities between pH 6.5 and 7.5, and are inactivated by heating at 56 degrees C. Furthermore, the neuraminidase and trans-sialidase reactions are coupled. An increase of the concentration of acceptors of the transfer reaction decreases the amount of free sialic acid released through the neuraminidase reaction. We conclude that a single enzyme can catalyze the transfer or the hydrolysis of macromolecular-bound sialic acid. The predominant direction of the reaction will depend on the availability of appropriate oligosaccharide acceptors of sialic acid.
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February 01 1992
Trypanosoma cruzi trans-sialidase and neuraminidase activities can be mediated by the same enzymes.
S Schenkman,
S Schenkman
Disciplina de Biologia Celular, Escola Paulista de Medicina, São Paulo, Brazil.
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L Pontes de Carvalho,
L Pontes de Carvalho
Disciplina de Biologia Celular, Escola Paulista de Medicina, São Paulo, Brazil.
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V Nussenzweig
V Nussenzweig
Disciplina de Biologia Celular, Escola Paulista de Medicina, São Paulo, Brazil.
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S Schenkman
Disciplina de Biologia Celular, Escola Paulista de Medicina, São Paulo, Brazil.
L Pontes de Carvalho
Disciplina de Biologia Celular, Escola Paulista de Medicina, São Paulo, Brazil.
V Nussenzweig
Disciplina de Biologia Celular, Escola Paulista de Medicina, São Paulo, Brazil.
Online ISSN: 1540-9538
Print ISSN: 0022-1007
J Exp Med (1992) 175 (2): 567–575.
Citation
S Schenkman, L Pontes de Carvalho, V Nussenzweig; Trypanosoma cruzi trans-sialidase and neuraminidase activities can be mediated by the same enzymes.. J Exp Med 1 February 1992; 175 (2): 567–575. doi: https://doi.org/10.1084/jem.175.2.567
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