Trypanosoma cruzi trans-sialidase and neuraminidase activities can be mediated by the same enzymes.

Abstract

SummaryTrans-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~ Furthermore, the neuraminidase and trans-sialidase reactions are coupled. An increase of the concentration of acceptors of the transfer reaction decreases the amount of flee 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.

Proteomic analysis reveals different composition of extracellular vesicles released by two Trypanosoma cruzi strains associated with their distinct interaction with host cells

“…Our analysis also detected more hits for Group I in the YuYu EVs, which correspond to the proteins containing TS activity, in agreement with our Western blot analysis, which used an antibody to recognize the carboxy-terminal domain of the TS repeats, also denominated shed acute phase antigen (SAPA) [23]. The TS enzymes are known to be released by trypomastigotes and influence the host infectivity [12,44,45] and to stimulate the production of IL-6 in intestinal microvascular endothelial cells and peripheral blood mononuclear cells [46].…”

“…In contrast, we detected the presence of the group II more abundantly in the Y-EVs, which correspond to the 85 kDa family of glycoproteins involved in the parasite interaction with host cells. Those proteins harbour the typical FLY sequence and two sialidase domains [4,5,23,42] and monoclonal antibodies against one set of these proteins, called Tc85, partially inhibits the host’s cell invasion by the parasite [43]. …”

Trans-sialidase delivered as a naked DNA vaccine elicits an immunological response similar to a Trypanosoma cruzi infection

“…In trypomastigote forms found in the vertebrate host, TS is formed by multimeric aggregates with molecular mass ³400 kDa (15,16), that upon denaturation migrates as multiple bands ranging from 160 to 220 kDa in SDS-PAGE (13,17). Trypomastigote TS has essentially 2 different domains.…”

“…Many of these proteins have been implicated in a number of biological processes important for T. cruzi interaction with host cells and extra-cellular matrix proteins (6)(7)(8)(9)(10)(11). One group of these proteins are enzymes denominated transsialidase (TS) that catalyze the transfer of sialic acid to ß-galactosyl residues of mucinlike glycoproteins that are present on the surface of T. cruzi trypomastigotes and epimastigotes (12,13).…”

Relevant glycoconjugates on the surface of Trypanosoma cruzi

“…Parodi et al (1992) demonstrated that the activities of neuraminidase and trans-sialidase co-precipitated with the same antibody, and Schenkman et al (1992) unequivocally showed that both activities belonged to the same enzyme. Finally, when the deduced amino acid sequence from TCNA was compared with the sequence of SAPA there was 84% homology corresponding to 93% of sequence identity in the nucleotide sequence.…”