TY - JOUR
T1 - The occurrence of internal (1,5)-linked arabinofuranose and arabinopyranose residues in arabinogalactan side chains from soybean pectic substances
AU - Huisman, M.M.H.
AU - Brüll, L.P.
AU - Thomas-Oates, J.E.
AU - Haverkamp, J.
AU - Schols, H.A.
AU - Voragen, A.G.J.
PY - 2001
Y1 - 2001
N2 - CDTA-extractable soybean pectic substances were subjected to enzymatic digestion with arabinogalactan degrading enzymes yielding a resistant polymeric pectic backbone and arabino-, galacto-, and arabinogalacto-oligomers. The complex digest was fractionated using size-exclusion chromatography. Monosaccharide composition analysis, HPAEC fractionation and MALDI-TOF MS analysis of the resulting fractions showed that each contained a mixture of oligosaccharides of essentially the same degree of polymerisation, composed of only arabinose and galactose. MALDI-TOF MS analysis was used for molecular mass screening of oligosaccharides in underivatised HPAEC fractions. The monosaccharide sequence and the branching pattern of oligosaccharides (degree of polymerisation from 4 to 8) were determined using linkage analysis and ES-CID tandem MS analysis of the per-O-methylated oligosaccharides in each of the HPAEC fractions. These analyses indicated the presence of common linear (1¿4)-linked galacto-oligosaccharides, and both linear and branched arabino-oligosaccharides. In addition, the results unambiguously showed the presence of oligosaccharides containing (1¿4)-linked galactose residues bearing an arabinopyranose residue as the non-reducing terminal residue, and a mixture of linear oligosaccharides constructed of (1¿4)-linked galactose residues interspersed with an internal (1¿5)-linked arabinofuranose residue. The consequences of these two new structural features of pectic arabinogalactan side chains are discussed
AB - CDTA-extractable soybean pectic substances were subjected to enzymatic digestion with arabinogalactan degrading enzymes yielding a resistant polymeric pectic backbone and arabino-, galacto-, and arabinogalacto-oligomers. The complex digest was fractionated using size-exclusion chromatography. Monosaccharide composition analysis, HPAEC fractionation and MALDI-TOF MS analysis of the resulting fractions showed that each contained a mixture of oligosaccharides of essentially the same degree of polymerisation, composed of only arabinose and galactose. MALDI-TOF MS analysis was used for molecular mass screening of oligosaccharides in underivatised HPAEC fractions. The monosaccharide sequence and the branching pattern of oligosaccharides (degree of polymerisation from 4 to 8) were determined using linkage analysis and ES-CID tandem MS analysis of the per-O-methylated oligosaccharides in each of the HPAEC fractions. These analyses indicated the presence of common linear (1¿4)-linked galacto-oligosaccharides, and both linear and branched arabino-oligosaccharides. In addition, the results unambiguously showed the presence of oligosaccharides containing (1¿4)-linked galactose residues bearing an arabinopyranose residue as the non-reducing terminal residue, and a mixture of linear oligosaccharides constructed of (1¿4)-linked galactose residues interspersed with an internal (1¿5)-linked arabinofuranose residue. The consequences of these two new structural features of pectic arabinogalactan side chains are discussed
KW - Arabinogalacto-oligosaccharides
KW - Internal arabinofuranose residues
KW - Soybean
KW - Terminal arabinopyranose residues
U2 - 10.1016/S0008-6215(00)00269-X
DO - 10.1016/S0008-6215(00)00269-X
M3 - Article
SN - 0008-6215
VL - 330
SP - 103
EP - 114
JO - Carbohydrate Research : an international journal
JF - Carbohydrate Research : an international journal
ER -