Chemo-enzymatic synthesis of a divalent sialyl Lewis(x) ligand with restricted flexibility.
To study the influence of the entropic factor in cluster cooperative effects, a divalent sialyl Lewis(x) ligand with restricted flexilbility was chemo-enzymatically synthesized. First, a cyclized precursor with both glucosamine residues bridged together by a succinyl group was readily obtained in 42% yield by treatment of 2,2-bis(benzyloxymethyl)-1,3-bis(3,4,6-tri-O-acetyl-2-amino-2-deoxy-beta-D-glucopyranosyloxy)-propane with succinyl chloride. After deacetylation, this precursor was subjected to stepwise enzymatic elongation utilizing successively, soluble galactosyltransferase, then recombinant sialyltransferase and fucosyltransferase; the latter enzymes immobilized on Ni(2+)-Agarose, to afford, after debenzylation, a divalent sialyl Lewis(x) ligand of restricted flexibility, in 45% overall yield. Following the same enzymatic sequence, a totally flexible ligand, required as a reference compound for evaluation of inhibitory activity toward selectins, was also prepared from 2,2(bis-benzyloxymethyl)-1,3-bis(2-acetamido-2-deoxy-beta-D-glucopyranosyloxy)-propane, as well as both related divalent Lewis(x) molecules lacking the sialic acids, the rigid one and the flexible one.
Laboratoire de Chimie Organique Multifonctionnelle, UMR 8614, Université de Paris-Sud, F-91405, Orsay, France.
Fabrice
F
Bintein
Claudine
C
Augé
André
A
Lubineau
D002240:Carbohydrate Sequence; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005647:Fucosyltransferases / Q000737:chemistry / Q000378:metabolism; D016695:Glycosyltransferases / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D015203:Reproducibility of Results; D019087:Selectins / Q000737:chemistry / Q000378:metabolism; D012685:Sepharose / Q000737:chemistry; D000080506:Sialyl Lewis X Antigen; D012799:Sialyltransferases / Q000737:chemistry / Q000378:metabolism
D004800:Enzymes, Immobilized; D008024:Ligands; D009844:Oligosaccharides; D011994:Recombinant Proteins; D019087:Selectins; D000080506:Sialyl Lewis X Antigen; D009532:Nickel; D012685:Sepharose; D016695:Glycosyltransferases; D005647:Fucosyltransferases; D012799:Sialyltransferases