Glycome: The total collection of glycans synthesized by a cell, a tissue, or an organism under specified conditions of time, space, and environment.
Glycomics: Systematic analysis of the glycome.
Glycomimetics: Noncarbohydrate compounds that mimic the properties of glycans.
Glycopeptide: A peptide having one or more covalently attached glycans. Glycoprotein: A protein with one or more covalently bound glycans.
Glycoproteomics: The systems-level analysis of glycoproteins, including their protein identities, sites of glycosylation, and glycan structures.
Glycosaminoglycans: Polysaccharide side chains of proteoglycans or free complex polysaccharides composed of linear disaccharide repeating units, each composed of a hexosamine and a hexose or a hexuronic acid.
Glycosidase: An enzyme that catalyzes the hydrolysis of glycosidic bonds in a glycan.
Glycoside: A glycan containing at least one glycosidic linkage to another glycan or an aglycone.
Glycosidic linkage: Linkage of a monosaccharide to another residue via the anomeric hydroxyl group. The linkage generally results from the reaction of a hemiacetal with an alcohol (e.g., a hydroxyl group on another monosaccharide or amino acid) to form an acetal. Glycosidic linkages between two monosaccharides have defined regiochemistry and stereochemistry.
Glycosyl acceptor: The nucleophile in a glycosylation reaction, usually containing a free hydroxyl group.
Glycosylation: The enzyme-catalyzed covalent attachment of a carbohydrate to a polypeptide, lipid, polynucleotide, carbohydrate, or other organic compound, generally catalyzed by glycosyltransferases, utilizing specific sugar nucleotide donor substrates.
Glycosyl donor: The electrophile in a glycosylation reaction; the nucleotide sugar in an enzymatic glycosylation reaction.
Glycosyltransferase: The enzyme that catalyzes transfer of a sugar from a sugar nucleotide donor to a substrate.
Heparan sulfate: A glycosaminoglycan defined by the disaccharide unit (GlcNAcα1–4GlcAβ1–4/IdoAα1–4), containing N- and O-sulfate esters at various positions, and typically found covalently linked to a proteoglycan core protein.
Heparin: A type of heparan sulfate made by mast cells that has the highest amount of iduronic acid and N- and O-sulfate residues. Pharmaceutical heparin binds and activates antithrombin.