title: Increased expression of the selectin ligand sialyl-Lewis(x) by biochemical engineering of sialic acids.
abstract: Sialylation of glycoproteins and glycolipids plays an important role during development, regeneration and pathogenesis of several diseases. The precursor of all physiological sialic acids is N-acetyl-d-mannosamine. Using N-propanoyl mannosamine, a novel precursor of sialic acid, we showed earlier that sialic acids with a prolonged N-acyl side chain (e.g., N-propanoyl neuraminic acid) are incorporated into cell surface glycoconjugates. In this study, we report the structural and functional consequences of the incorporation of the nonphysiological sialic acid, N-propanoyl neuraminic acid, into glycoconjugates of HL60-I cells. These cells do not express UDP-GlcAc-2-epimerase, the key enzyme of the biosynthesis of N-acetyl-d-mannosamine. Therefore, they do not express sialyl-Lewis(x) structures and consequently do not bind to selectins. Application of N-acetyl-d-mannosamine leads to the expression of sialyl-Lewis(x) structures and to binding to selectins. Surprisingly, incorporation of N-propanoyl neuraminic acid into glycoconjugates of these cells leads to a dramatic increase of sialyl-Lewis(x) structures and to increased adhesion to selectins.
authors.affiliation: Institut für Molekularbiologie und Biochemie, Charité-Universitätsmedizin Berlin, 14195 Berlin-Dahlem, Germany. ruediger.horstkorte@medizin.fu-berlin.de
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Horstkorte
authors.forename: Kirstin
authors.initials: K
authors.lastname: Rau
authors.forename: Werner
authors.initials: W
authors.lastname: Reutter
authors.forename: Sabine
authors.initials: S
authors.lastname: Nöhring
authors.forename: Lothar
authors.initials: L
authors.lastname: Lucka
mesh_terms: D002448:Cell Adhesion; D000939:Epitopes; D015870:Gene Expression; D018922:HL-60 Cells; D006801:Humans; D019041:L-Selectin / Q000378:metabolism*; D007983:Lewis Blood Group Antigens; D008024:Ligands; D008562:Membrane Glycoproteins / Q000378:metabolism; D008954:Models, Biological; D019158:N-Acetylneuraminic Acid / Q000493:pharmacokinetics*; D015202:Protein Engineering / Q000379:methods*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D019087:Selectins / Q000378:metabolism; D012794:Sialic Acids / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D000939:Epitopes; D007983:Lewis Blood Group Antigens; D008024:Ligands; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D019087:Selectins; D012794:Sialic Acids; D019041:L-Selectin; D019158:N-Acetylneuraminic Acid