UNASSIGNED: Fourteen different active Trypanosoma congolense trans-sialidases (TconTS), 11 variants of TconTS1 besides TconTS2, TconTS3 and TconTS4, have been described. Notably, the specific transfer and sialidase activities of these TconTS differ by orders of magnitude. Surprisingly, phylogenetic analysis of the catalytic domains (CD) grouped each of the highly active TconTS together with the less active enzymes. In contrast, when aligning lectin-like domains (LD), the highly active TconTS grouped together, leading to the hypothesis that the LD of TconTS modulates its enzymatic activity. So far, little is known about the function and ligand specificity of these LDs. To explore their @entity1735 -binding potential, glycan array analysis was performed on the LD of TconTS1, TconTS2, TconTS3 and TconTS4. In addition, Saturation Transfer Difference (STD) NMR experiments were done on TconTS2-LD for a more detailed analysis of its lectin activity. Several @entity3913 -containing oligosaccharides, such as @entity68097 , @entity60934 and higher mannosylated glycans, as well as @entity19447 , @entity26243 and @entity48891 containing oligosaccharides were confirmed as binding partners of TconTS1-LD and TconTS2-LD. Interestingly, terminal @entity3913 residues are not acceptor substrates for TconTS activity. This indicates a different, yet unknown biological function for TconTS-LD, including specific interactions with oligomannose-containing glycans on glycoproteins and GPI anchors found on the surface of the parasite, including the TconTS itself. Experimental evidence for such a scenario is presented.

XXXX Recognition Specificity of Trans-sialidase Lectin Domain from Trypanosoma congolense.

@entity1735 :: ('CHEBI:16646', 'Chemical') :: ['carbohydrate'] @entity60934 :: ('MESH:C023872', 'Chemical') :: ['mannotriose'] @entity48891 :: ('CHEBI:16153', 'Chemical') :: ['LacNAc'] @entity3913 :: ('MESH:D008358', 'Chemical') :: ['mannose'] @entity68097 :: ('MESH:C014647', 'Chemical') :: ['mannobiose'] @entity26243 :: ('CHEBI:28037', 'Chemical') :: ['GalNAc'] @entity19447 :: ('CHEBI:28260', 'Chemical') :: ['Gal']
@entity1735 :: (CHEBI:16646,Chemical) :: ['Carbohydrate']
