Conformational studies on five octasaccharides isolated from chondroitin sulfate using NMR spectroscopy and molecular modeling.
Chondroitin sulfate proteoglycans (CS-PG) are involved in the regulation of the central nervous system in vertebrates due to their presence on cell surfaces and in the extracellular matrix of tissues. The CS moieties are built up from repeating -4)GlcA(beta1-3)GalNAc(beta1- disaccharide units, partly O-sulfated at different positions. The presence of the disulfated disaccharide D-unit, GlcA2S(beta1-3)GalNAc6S, in the CS moiety of the proteoglycan DSD-1-PG/phosphacan, correlates with neurite outgrowth promotion. The binding of monoclonal antibody (mAb) 473HD to DSD-1-PG, reducing neuronal stimulation, is inhibited by shark cartilage CS-D. CS-D is also recognized by two other mAbs, MO-225 and CS-56. Conformational studies were performed using NMR spectroscopy and molecular modeling on five octasaccharides isolated from shark cartilage CS-D. These octasaccharides present different binding properties toward the three mAbs. The combination of the experimental and theoretical approaches revealed that the sulfate group at position 2 of GlcA in disaccharide D and the presence of an exocyclic negative tail in disaccharides C [GlcA(beta1-3)GalNAc6S] and DeltaC [Delta4,5HexA(alpha1-3)GalNAc6S] are important for antibody recognition.
Blanchard
Véronique
V
Bijvoet Center, Department of Bio-Organic Chemistry, Utrecht University, Padualaan 8, NL-3584 CH Utrecht, The Netherlands.
Chevalier
Franck
F
Imberty
Anne
A
Leeflang
Bas R
BR
Basappa
Sugahara
Kazuyuki
K
Kamerling
Johannis P
JP
D000818:Animals; D000911:Antibodies, Monoclonal; D000937:Antigen-Antibody Reactions; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002809:Chondroitin Sulfates / Q000737:chemistry* / Q000276:immunology; D004187:Disaccharides / Q000276:immunology; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008958:Models, Molecular; D016501:Neurites / Q000648:ultrastructure; D009457:Neuroglia; D009844:Oligosaccharides / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D011509:Proteoglycans / Q000737:chemistry; D013431:Sulfates
D000911:Antibodies, Monoclonal; D004187:Disaccharides; D009844:Oligosaccharides; D011509:Proteoglycans; D013431:Sulfates; D002809:Chondroitin Sulfates