title: Evidence of ternary complex formation in Trypanosoma cruzi trans-sialidase catalysis.
abstract: Trypanosoma cruzi trans-sialidase (TcTS) is a key target protein for Chagas disease chemotherapy. In this study, we investigated the implications of active site flexibility on the biochemical mechanism of TcTS. Molecular dynamics studies revealed remarkable plasticity in the TcTS catalytic site, demonstrating, for the first time, how donor substrate engagement with the enzyme induces an acceptor binding site in the catalytic pocket that was not previously captured in crystal structures. Furthermore, NMR data showed cooperative binding between donor and acceptor substrates, supporting theoretical results. In summary, our data put forward a coherent dynamic framework to understand how a glycosidase evolved its highly efficient trans-glycosidase activity.
authors.affiliation: From the Laboratório de Glicobiologia Estrutural e Funcional, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro RJ 21941-902, Brazil.
authors.forename: Isadora A
authors.initials: IA
authors.lastname: Oliveira
authors.forename: Arlan S
authors.initials: AS
authors.lastname: Gonçalves
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Neves
authors.forename: Mark
authors.initials: M
authors.lastname: von Itzstein
authors.forename: Adriane R
authors.initials: AR
authors.lastname: Todeschini
mesh_terms: D002384:Catalysis; D020134:Catalytic Domain; D019143:Evolution, Molecular; D006023:Glycoproteins; D056004:Molecular Dynamics Simulation; D009439:Neuraminidase; D019906:Nuclear Magnetic Resonance, Biomolecular; D015800:Protozoan Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000235:genetics
chemical_list: D006023:Glycoproteins; D015800:Protozoan Proteins; C069715:trans-sialidase; D009439:Neuraminidase
keywords: Carbohydrate Glycoconjugate; Enzyme Mechanisms; Enzyme Structure; Glycosidases; Molecular Dynamics; Nuclear Magnetic Resonance; Sialic Acid; Sialidase; Trypanosoma cruzi; trans-Sialidase