The solution structure of ganglioside G(M1) carbohydrate moiety at the surface of a 102-kDa lipid-modified-G(M1) micelle is investigated by high-resolution H-1-NMR in H2O. The micellar surface can be considered a cluster-like lateral distribution of the gangliosides, each single monomer being anchored in a carbohydrate-enriched model membrane matrix. H-1 NOESY measurements at short mixing times reveal a rigid trisaccharide core -beta-GalNAc-(1-4)-[alpha-Neu5Ac-(2-3)]-beta-Gal- and a more flexible beta-Gal-(1-3)-beta-GalNAc- terminal glycosidic bond. in the lipid-modified G(M1) ganglioside micellar system, there is no evidence that intermolecular side-by-side carbohydrate interactions modulate, or alter in any way, the head-group spatial arrangement. Possible intermonomer interactions at the level of the branched trisaccharide portion were further investigated on mixed micelles of natural N-glycolyl- and N-acetylneuraminic acid containing G(M1) in D2O, taking advantage of the different NMR features of N-glycoyl- and N-acetylneuraminic acids, which allow discrimination between sialic acid ring proton signals. Measurements of the water/ganglioside-OH proton chemical exchange rates suggest hydroxyl group involvement at position 8 of sialic acid in strong intramolecular interaction processes.
Conformation of the oligosaccharide chain of G(M1) ganglioside in a carbohydrate-enriched surface / P. Brocca, P. Berthault, S. Sonnino. - In: BIOPHYSICAL JOURNAL. - ISSN 0006-3495. - 74:1(1998), pp. 309-318.
Titolo: | Conformation of the oligosaccharide chain of G(M1) ganglioside in a carbohydrate-enriched surface |
Autori: | BROCCA, PAOLA (Primo) SONNINO, SANDRO (Ultimo) |
Settore Scientifico Disciplinare: | Settore FIS/07 - Fisica Applicata(Beni Culturali, Ambientali, Biol.e Medicin) Settore BIO/10 - Biochimica |
Data di pubblicazione: | 1998 |
Rivista: | |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/S0006-3495(98)77788-4 |
Appare nelle tipologie: | 01 - Articolo su periodico |