Conformational preferences of the aglycon moiety in models and analogs of GlcNAc-Asn linkage: Crystal structures and ab initio quantum chemical calculations of N-(?-D-glycopyranosyl)haloacetamides
| Autor: | Mohamed Mohamed Naseer Ali, Anne Imberty, Duraikkannu Loganathan, Serge Pérez, Udayanath Aich, Babu Varghese |
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| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Models
Molecular chemistry.chemical_classification Glycosylation Chemistry Stereochemistry Hydrogen bond Molecular Conformation Ab initio General Chemistry Crystal structure Dihedral angle Oligosaccharide Crystallography X-Ray Biochemistry Catalysis Acetylglucosamine Crystallography Colloid and Surface Chemistry Ab initio quantum chemistry methods Amines Amino acids Glucose Glycoproteins Organic acids Quantum chemistry Sugar (sucrose) Sugars Supramolecular chemistry Ab Initio quantum chemical calculations Asparagine residues Conformational preferences D-glucopyranose Gain information Glycosylated Structure and dynamics Proteins 2 acetamino 2 deoxy beta dextro glucopyranose monosaccharide acetamide derivative aglycone asparagine chloroacetamide glycan glycoprotein monosaccharide n (beta dextro glycopyranosyl)haloacetamide derivative oligosaccharide peptide ab initio calculation biosynthesis chemical structure complex formation conformational transition crystal structure density functional theory eukaryote glycosylation hydrogen bond molecular dynamics molecular mechanics protein analysis quantum chemistry Asparagine Protein Processing Post-Translational Moiety Macromolecule |
| Zdroj: | IndraStra Global. |
| ISSN: | 2381-3652 |
| DOI: | 10.1021/ja800335m |
| Popis: | The biological addition of oligosaccharide structures to asparagine residues of N-glycoproteins influences the properties and bioactivities of these macromolecules. The linkage region constituents, 2-acetamino-2-deoxy-?-D- glucopyranose monosaccharide (GlcNAc) and L-asparagine amino acid (Asn), are conserved in the N-glycoproteins of all eukaryotes. In order to gain information about the structure and dynamics of glycosylated proteins, two chloroacetamido sugars, Glc?NAcNHCOCH2Cl and Man?NHCOCH2Cl, have been synthesized, and their crystal structures have been solved. Structural comparison with a series of other models and analogs gives insight about the influence of the N-acetyl group at position C2 on the conformation of the glycan-peptide linkage at C1. Interestingly, this N-acetyl group also influences the packing and network of hydrogen bonds with involvement in weak hydrogen bonds C-H?X that are of biological importance. DFT ab initio calculations performed on a series of models and analogs also confirm that the GlcNAc derivatives present different preferred conformation about the N-CO-CH 2-X (?2) torsion angle of the glycan-peptide linkage, when compared to other monosaccharide derivatives. The energy profiles that have been obtained will be useful for parametrization of molecular mechanics force-field. The conjunction of crystallographic and computational chemistry studies provides arguments for the structural effect of the N-acetyl group at C2 in establishing an extended conformation that presents the oligosaccharide away from the protein surface. � 2008 American Chemical Society. |
| Databáze: | OpenAIRE |
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