title: A single N-acetylgalactosamine residue at threonine 106 modifies the dynamics and structure of interferon α2a around the glycosylation site.
abstract: Enzymatic addition of GalNAc to isotopically labeled IFNα2a produced in Escherichia coli yielded the O-linked glycoprotein GalNAcα-[(13)C,(15)N]IFNα2a. The three-dimensional structure of GalNAcα-IFNα2a has been determined in solution by NMR spectroscopy at high resolution. Proton-nitrogen heteronuclear Overhauser enhancement measurements revealed that the addition of a single monosaccharide unit at Thr-106 significantly slowed motions of the glycosylation loop on the nanosecond time scale. Subsequent addition of a Gal unit produced Gal(β1,3)GalNAcα-[(13)C,(15)N]IFNα2a. This extension resulted in a further decrease in the dynamics of this loop. The methodology used here allowed the first such description of the structure and dynamics of an O-glycoprotein and opens the way to the study of this class of proteins.
authors.affiliation: Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, Health Canada, Ottawa, Ontario K1A 0K9, Canada.
authors.forename: Houman
authors.initials: H
authors.lastname: Ghasriani
authors.forename: Pascal J F
authors.initials: PJ
authors.lastname: Belcourt
authors.forename: Simon
authors.initials: S
authors.lastname: Sauvé
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Hodgson
authors.forename: Denis
authors.initials: D
authors.lastname: Brochu
authors.forename: Michel
authors.initials: M
authors.lastname: Gilbert
authors.forename: Yves
authors.initials: Y
authors.lastname: Aubin
mesh_terms: D000116:Acetylgalactosamine / Q000737:chemistry* / Q000235:genetics; D019295:Computational Biology / Q000379:methods; D004220:Disulfides / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000378:metabolism*; D007372:Interferons / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D010455:Peptides / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000378:metabolism; D013912:Threonine / Q000737:chemistry*
chemical_list: D004220:Disulfides; D006023:Glycoproteins; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D010455:Peptides; D011134:Polysaccharides; D011994:Recombinant Proteins; D013912:Threonine; D007372:Interferons; D000116:Acetylgalactosamine