TY - JOUR
T1 - High resolution proton NMR studies of gangliosides. Structure of two types of G(D3) lactones and their reactivity with monoclonal antibody R24
AU - Ando, S.
AU - Yu, R. K.
AU - Scarsdale, J. N.
AU - Kusunoki, S.
AU - Prestegard, J. H.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1989
Y1 - 1989
N2 - Gangioside G(D3) was converted at room temperature to two stable lactones, denoted as G(D3) lactones I and II. The reaction sequence was presumed to be G(D3) → G(D3) lactone I → G(D3) lactone II based on the time course of their production. Lactone I behaved as a monosialoganglioside and lactone II as a neutral species. The two lactones were isolated by DEAE-Sephadex column chromatography. The positions of the inner ester linkages were investigated by two-dimensional J-correlated proton NMR spectroscopy. An ester linkage was most likely formed between the carboxyl group of the external sialic acid residue and C9-OH of the internal sialic acid residue in lactone I. In addition to this ester linkage, a second ester linkage between the carboxyl group of the internal sialic acid and C2-OH of the galactose residue was likely formed in lactone II. The structural changes induced by lactonization were further examined by their reactivity with the monoclonal antibody R24 (Puckel, C.S., Lloyd, K.O., Travassos, L.R., Dippold, W.G., Oettgen, H.F., and Old, L.J. (1982) J. Exp. Med. 155, 1133-1147), which reacted with G(D3). R24 was found to bind weakly to G(D3) lactone I, but not to G(D3) lactone II. The results suggest that the monoclonal antibody requires both sialic acid residues for high affinity binding, and the complete lactonization results in a loss of negative charges and/or a change in the overall conformation of the oligosaccharide moiety which may account for the loss of binding.
AB - Gangioside G(D3) was converted at room temperature to two stable lactones, denoted as G(D3) lactones I and II. The reaction sequence was presumed to be G(D3) → G(D3) lactone I → G(D3) lactone II based on the time course of their production. Lactone I behaved as a monosialoganglioside and lactone II as a neutral species. The two lactones were isolated by DEAE-Sephadex column chromatography. The positions of the inner ester linkages were investigated by two-dimensional J-correlated proton NMR spectroscopy. An ester linkage was most likely formed between the carboxyl group of the external sialic acid residue and C9-OH of the internal sialic acid residue in lactone I. In addition to this ester linkage, a second ester linkage between the carboxyl group of the internal sialic acid and C2-OH of the galactose residue was likely formed in lactone II. The structural changes induced by lactonization were further examined by their reactivity with the monoclonal antibody R24 (Puckel, C.S., Lloyd, K.O., Travassos, L.R., Dippold, W.G., Oettgen, H.F., and Old, L.J. (1982) J. Exp. Med. 155, 1133-1147), which reacted with G(D3). R24 was found to bind weakly to G(D3) lactone I, but not to G(D3) lactone II. The results suggest that the monoclonal antibody requires both sialic acid residues for high affinity binding, and the complete lactonization results in a loss of negative charges and/or a change in the overall conformation of the oligosaccharide moiety which may account for the loss of binding.
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M3 - Article
C2 - 2914959
AN - SCOPUS:0024574168
SN - 0021-9258
VL - 264
SP - 3478
EP - 3483
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 6
ER -