Sulphated Mucin Oligosaccharides from Porcine Small Intestine Analysed by Four-Sector Tandem Mass Spectrometry
摘要:
The fraction of sulphated oligosaccharide alditols isolated from mucin glycopeptides of porcine small intestine 'insoluble' mucin complex was analysed by negative-ion fast atom bombardment (FAB) tandem mass spectrometry. Collision-induced dissociation (CID) tandem mass spectra of native and peracetylated species were compared with standards of sulphated monosaccharides. The tandem mass spectra revealed structural information of the carbohydrate sequence and sulphate position. Negative-ion FAB ionization of the peracetylated sulphated oligo-saccharide alditols was at least three times more sensitive than that of the native sulphated oligosaccharide alditols, as revealed by comparing the signal-to-noise ratios, and allowed the detection of eleven compared with six pseudo-molecular ions. Fourteen structures were determined from the CID tandem mass spectra obtained. The main sulphation site was C-6 of an N-acetylglucosamine 6-linked to the N-acetylgalactosaminitol. C-3 of the N-acetylgalactosaminitol could be unsubstituted or extended with a series of up to three monosaccharide residues including blood group H determinants and blood group A determinants. Also, the sulphated N-acetylglucosamine could be further extended. The most abundant structure was a monosulphated trisaccharide with the sequence Gal-->3(SO3-->6GlcNAc-->6)GalNAcol. The sulphation at C-6 of N-acetylglucosamine seems to be a common feature for O-linked oligosaccharides, and has been described both for skeletal keratan sulphates and respiratory mucin oligosaccharides. Low-abundance ions were also detected from oligosaccharides with sulphation at C-3 of an amino sugar residue. This seems to be a novel sulphation site for mucin oligosaccharides.
Improved long wavelength-emitting chemiluminescent probes are easy to synthesize and are well-suited for both in vitro and in vivo applications, but are particularly well-suited for in vivo applications. The wavelengths of the emissions of the probes include those in the orange, red or NIR range. Dioxetane compounds and phenolic ester compounds are included.
Sulphated Mucin Oligosaccharides from Porcine Small Intestine Analysed by Four-Sector Tandem Mass Spectrometry
作者:Niclas G. Karlsson、Hasse Karlsson、Gunnar C. Hansson
The fraction of sulphated oligosaccharide alditols isolated from mucin glycopeptides of porcine small intestine 'insoluble' mucin complex was analysed by negative-ion fast atom bombardment (FAB) tandem mass spectrometry. Collision-induced dissociation (CID) tandem mass spectra of native and peracetylated species were compared with standards of sulphated monosaccharides. The tandem mass spectra revealed structural information of the carbohydrate sequence and sulphate position. Negative-ion FAB ionization of the peracetylated sulphated oligo-saccharide alditols was at least three times more sensitive than that of the native sulphated oligosaccharide alditols, as revealed by comparing the signal-to-noise ratios, and allowed the detection of eleven compared with six pseudo-molecular ions. Fourteen structures were determined from the CID tandem mass spectra obtained. The main sulphation site was C-6 of an N-acetylglucosamine 6-linked to the N-acetylgalactosaminitol. C-3 of the N-acetylgalactosaminitol could be unsubstituted or extended with a series of up to three monosaccharide residues including blood group H determinants and blood group A determinants. Also, the sulphated N-acetylglucosamine could be further extended. The most abundant structure was a monosulphated trisaccharide with the sequence Gal-->3(SO3-->6GlcNAc-->6)GalNAcol. The sulphation at C-6 of N-acetylglucosamine seems to be a common feature for O-linked oligosaccharides, and has been described both for skeletal keratan sulphates and respiratory mucin oligosaccharides. Low-abundance ions were also detected from oligosaccharides with sulphation at C-3 of an amino sugar residue. This seems to be a novel sulphation site for mucin oligosaccharides.