title: Carbohydrate Recognition Specificity of Trans-sialidase Lectin Domain from Trypanosoma congolense.
abstract: 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 carbohydrate-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 mannose-containing oligosaccharides, such as mannobiose, mannotriose and higher mannosylated glycans, as well as Gal, GalNAc and LacNAc containing oligosaccharides were confirmed as binding partners of TconTS1-LD and TconTS2-LD. Interestingly, terminal mannose 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.
authors.affiliation: Centre for Biomolecular Interactions Bremen, Faculty for Biology and Chemistry, University Bremen, Bremen, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Waespy
authors.affiliation: Centre for Biomolecular Interactions Bremen, Faculty for Biology and Chemistry, University Bremen, Bremen, Germany; Africa Centre of Excellence for Neglected Tropical Diseases and Forensic Biotechnology, Ahmadu Bello University, Zaria, Nigeria.
authors.forename: Thaddeus T
authors.initials: TT
authors.lastname: Gbem
authors.affiliation: Centre for Biomolecular Interactions Bremen, Faculty for Biology and Chemistry, University Bremen, Bremen, Germany.
authors.forename: Leroy
authors.initials: L
authors.lastname: Elenschneider
authors.affiliation: Centre for Biomolecular Interactions Bremen, Faculty for Biology and Chemistry, University Bremen, Bremen, Germany.
authors.forename: André-Philippe
authors.initials: AP
authors.lastname: Jeck
authors.affiliation: Institute for Glycomics, Griffith University Gold Coast Campus, Queensland, Australia.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Day
authors.affiliation: Institute for Glycomics, Griffith University Gold Coast Campus, Queensland, Australia.
authors.forename: Lauren
authors.initials: L
authors.lastname: Hartley-Tassell
authors.affiliation: Shemyakin Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Nicolai
authors.initials: N
authors.lastname: Bovin
authors.affiliation: Institute for Glycomics, Griffith University Gold Coast Campus, Queensland, Australia.
authors.forename: Joe
authors.initials: J
authors.lastname: Tiralongo
authors.affiliation: Institute for Glycomics, Griffith University Gold Coast Campus, Queensland, Australia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Haselhorst
authors.affiliation: Centre for Biomolecular Interactions Bremen, Faculty for Biology and Chemistry, University Bremen, Bremen, Germany; Africa Centre of Excellence for Neglected Tropical Diseases and Forensic Biotechnology, Ahmadu Bello University, Zaria, Nigeria; Institute for Glycomics, Griffith University Gold Coast Campus, Queensland, Australia.
authors.forename: Sørge
authors.initials: S
authors.lastname: Kelm
mesh_terms: D001665:Binding Sites; D002241:Carbohydrates / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D037102:Lectins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose / Q000737:chemistry; D009439:Neuraminidase / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D014348:Trypanosoma congolense / Q000201:enzymology*
chemical_list: D002241:Carbohydrates; D006023:Glycoproteins; D037102:Lectins; C069715:trans-sialidase; D009439:Neuraminidase; D008358:Mannose