title: Lipid-linked oligosaccharides in membranes sample conformations that facilitate binding to oligosaccharyltransferase.
abstract: Lipid-linked oligosaccharides (LLOs) are the substrates of oligosaccharyltransferase (OST), the enzyme that catalyzes the en bloc transfer of the oligosaccharide onto the acceptor asparagine of nascent proteins during the process of N-glycosylation. To explore LLOs' preferred location, orientation, structure, and dynamics in membrane bilayers of three different lipid types (dilauroylphosphatidylcholine, dimyristoylphosphatidylcholine, and dioleoylphosphatidylcholine), we have modeled and simulated both eukaryotic (Glc3-Man9-GlcNAc2-PP-Dolichol) and bacterial (Glc1-GalNAc5-Bac1-PP-Undecaprenol) LLOs, which are composed of an isoprenoid moiety and an oligosaccharide, linked by pyrophosphate. The simulations show no strong impact of different bilayer hydrophobic thicknesses on the overall orientation, structure, and dynamics of the isoprenoid moiety and the oligosaccharide. The pyrophosphate group stays in the bilayer head group region. The isoprenoid moiety shows high flexibility inside the bilayer hydrophobic core, suggesting its potential role as a tentacle to search for OST. The oligosaccharide conformation and dynamics are similar to those in solution, but there are preferred interactions between the oligosaccharide and the bilayer interface, which leads to LLO sugar orientations parallel to the bilayer surface. Molecular docking of the bacterial LLO to a bacterial OST suggests that such orientations can enhance binding of LLOs to OST.
authors.affiliation: Department of Molecular Biosciences and Center for Bioinformatics, University of Kansas, Lawrence, Kansas.
authors.forename: Nathan R
authors.initials: NR
authors.lastname: Kern
authors.affiliation: Department of Molecular Biosciences and Center for Bioinformatics, University of Kansas, Lawrence, Kansas.
authors.forename: Hui Sun
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Molecular Biosciences and Center for Bioinformatics, University of Kansas, Lawrence, Kansas.
authors.forename: Emilia L
authors.initials: EL
authors.lastname: Wu
authors.affiliation: Department of Molecular Biosciences and Center for Bioinformatics, University of Kansas, Lawrence, Kansas.
authors.forename: Soohyung
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland.
authors.forename: Kenno
authors.initials: K
authors.lastname: Vanommeslaeghe
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland.
authors.forename: Alexander D
authors.initials: AD
authors.lastname: MacKerell
authors.affiliation: Department of Chemical and Biomolecular Engineering and Biophysics Program, University of Maryland, College Park, Maryland.
authors.forename: Jeffery B
authors.initials: JB
authors.lastname: Klauda
authors.affiliation: Department of Molecular Biosciences and Center for Bioinformatics, University of Kansas, Lawrence, Kansas.
authors.forename: Sunhwan
authors.initials: S
authors.lastname: Jo
authors.affiliation: Department of Molecular Biosciences and Center for Bioinformatics, University of Kansas, Lawrence, Kansas. Electronic address: wonpil@ku.edu.
authors.forename: Wonpil
authors.initials: W
authors.lastname: Im
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D006602:Hexosyltransferases / Q000737:chemistry / Q000378:metabolism*; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D011485:Protein Binding
chemical_list: D001426:Bacterial Proteins; D008051:Lipid Bilayers; D008070:Lipopolysaccharides; D008565:Membrane Proteins; C023023:lipid-linked oligosaccharides; D006602:Hexosyltransferases; C025620:dolichyl-diphosphooligosaccharide - protein glycotransferase