Reducing End Of Oligosaccharides Research Articles

Identification of Anomericity and Linkage of Arabinose and Ribose through Collision-Induced Dissociation.

Arabinose and ribose are two common pentoses that exist in both furanose and pyranose forms in plant and bacteria oligosaccharides. In this study, each pentose isomer, namely α-furanose, β-furanose, α-pyranose, and β-pyranose, was first separated through high-performance liquid chromatography followed by an investigation of collision-induced dissociation in an ion trap mass spectrometer. The major dissociation channels, dehydration and cross-ring dissociation, were analyzed by using high-level quantum chemistry calculations and transition state theory. The branching ratio of major dissociation channels was governed by two geometrical features: one being the cis or trans configuration of O1 and O2 atoms determining dehydration preferability and the other being the number of hydroxyl groups on the same side of the ring as the O1 atom determining the preferability of cross-ring dissociation. The relative branching ratios of the major channels were used to identify anomericity and the linkages of arabinose and ribose. Arabinose in the β-configuration and ribose in the α-configuration are predicted to have larger relative dehydration branching ratios than arabinose in the α-configuration and ribose in the β-configuration, respectively. Arabinose and ribose at the reducing end of oligosaccharides with 1 → 2 (pyranose and furanose), 1 → 3 (pyranose and furanose), 1 → 4 (pyranose only), and 1 → 5 (furanose only) linkages are predicted to undergo 0,2X, 0,3X, 0,2A, and 0,2A/0,3A cross-ring dissociation, respectively. Application of the dissociation mechanism to the disaccharide linkage determination is demonstrated.

Rapid and accurate profiling of oligosaccharides in beer by using a reactive matrix via MALDI-TOF MS

Oligosaccharides analysis is crucial for brewing technology. Herein, we reported a rapid and highly reproducible method for profiling of oligosaccharides in beer using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) by employing a reasonably designed reactive-matrix, 2-phenyl-3-(p-aminophenyl) acrylonitrile (PAPAN). The PAPAN enhanced ionization efficiency of oligosaccharides and improved reproducibility comparing to the use of conventional matrix, 2,5-dihydroxybenzoic acid (DHB). After optimization of sample dilution factor and cationization agents, the distributions of maltooligosaccharides in different brands of beers were unambiguously identified. Since the PAPAN selectively reacts with the reducing end of oligosaccharides, the interferences from matrixes are effectively eliminated. Therefore, the method shows potentials for analysis of oligosaccharides in other foods.

Probing cleavage promiscuity of heparinase III towards chemoenzymatically synthetic heparan sulfate oligosaccharides

An insightful investigation into specificity of bacterial heparinase III has been intriguingly difficult due to heterogeneity of polymeric substrates. Herein, we chemoenzymatically synthesized a tailored library of HS oligosaccharides as substrates. A ∼15-fold reactivity difference to heparinase III was found between trisaccharides bearing different primary cleavage sites. Variable glucosamine modification decreased reactivity of trisaccharides by >20-fold compared with their counterpart primary substrates, while iduronate-containing secondary linkage showed slightly less sensitivity. The 2-sulfated iduronate residue extremely reduced reactivity to its adjacent primary site at reducing end of oligosaccharides, but showed marginal influence on the non-reducing site. Moreover, oligosaccharide susceptibility to digestion was size-dependent and had an obvious preference for the internal linkages over those near to non-reducing/reducing ends. Surface plasmon resonance revealed cleavage promiscuity attributed to different affinities or incorrect binding of substrates to the enzyme. The attractive information on heparinase III will be valuable in characterizing heparin and HS.

Analysis of Saccharides Possessing Post-translational Protein Modifications by Phenylhydrazine Labeling Using High-Performance Liquid Chromatography

Sugar analysis by postcolumn labeling using phenylhydrazine with high-performance liquid chromatography is herein introduced. Phenylhydrazine reacts not only with the reducing end of oligosaccharides, but also with mono-sugar components with degraded glycosyl bonds. N-acethylhexosamine is highly sensitive at a sub-pico molecular range, and this method is useful for detecting glycans on glycoproteins. The detection limit of fetuin, a protein possessing 3 N-glycans and 3 O-glycans, was 0.17 pmol by infusion analysis, and chromatograms of glycopeptides separated on an ODS column were obtained. These results suggest that this method is useful for the preparation of glycopeptides for glyco-proteomics research.

ChemInform Abstract: Sequential Removal of Monosaccharides from the Reducing End of Oligosaccharides. Part 3. Preparation, Conformation, and Mild Hydrolysis of 1‐Glycosyl‐2‐acetylhydrazines of the Hexoses, Pentoses, 2‐Acetamido‐2‐deoxyhexoses, and Fucose.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Sequential Removal of Monosaccharides from the Reducing End of Oligosaccharides. 2. Fundamental Studies of a Reaction between Hydrazino Compounds and Sugars Having a Glycosyl Moiety on a Carbon Atom Adjacent to a Carbonyl Group

Sequential Removal of Monosaccharides from the Reducing End of Oligosaccharides. 2. Fundamental Studies of a Reaction between Hydrazino Compounds and Sugars Having a Glycosyl Moiety on a Carbon Atom Adjacent to a Carbonyl Group

ChemInform Abstract: Sequential Removal of Monosaccharides from the Reducing End of Oligosaccharides. Part 1. A Reaction Between Hydrazine and Sugars Having a Glycosidic Substituent on a Carbon Atom Adjacent to the Carbonyl Group.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Sequential removal of monosaccharides from the reducing end of oligosaccharides. I. A reaction between hydrazine and sugars having a glycosidic substituent on a carbon atom adjacent to the carbonyl group

Hydrazine reacts smoothly with sugars having a glycosidic substituent when the glycosyl moiety is located on a carbon atom adjacent to an aldehyde or keto group, resulting in cleavage of the glycosidic linkage. In excess hydrazine, the released glycoside forms a hydrazone from which the reducing sugar may be recovered in high yields.

Rat liver chitobiase: Purification, properties, and role in the lysosomal degradation of Asn-linked glycoproteins

Chitobiase, the lysosomal glycosidase responsible for splitting the GlcNAcβ- d-(1–4) GlcNAc moiety in Asn-linked glycoproteins, was purified over 600-fold from frozen rat livers utilizing an assay with di- N-acetylchitobiose as the substrate. The final preparation showed a major polypeptide of M r 43,000 (sodium dodecylsulfate-polyacrylamide gel electrophoresis) that was determined to be the chitobiase by an immunological method. The purified chitobiase also hydrolyzed tri- and tetrasaccharides of chitin, which like di- N-acetylchitobiose were not substrates if first reduced by NaBH 4. The initial products formed during hydrolysis of the tetrasaccharide were trisaccharide and GlcNAc. These results imply that chitobiase is a “reducing-end exohexosaminidase” which cleaves single GlcNAc units only from the reducing end of oligosaccharides. Fucose, typically found linked to the reducing-end GlcNAc in complex oligosaccharide chains, was found to block this reaction. Additional substrates that were hydrolyzed included GlcNAcβ- d-(1–4)MurNAc, the repeating structure from bacterial cell wall peptidoglycan, and the Manβ- d-(1–4)GlcNAcβ- d-(1–4)GlcNAc reducing-end component of glycoproteins. K m and V m for hydrolysis of these substrates were of similar magnitude as for di- N-acetylchitobiose (6.3 m m and 15 μmol/min/mg protein, respectively). Liver tissues from nine mammalian species were surveyed for the presence of chitobiase activity. The activity was found in rat, mouse, rabbit, and guinea pig liver (Stirling [(1974) FEBS Lett. 39, 171–175] previously observed the enzyme in human liver), but not in dog, sheep, pig, cat, and cow liver. The presence or absence of chitobiase so far observed was found to exactly correlate with the type of oligosaccharide fragments found to accumulate in animals containing genetic or inhibitor-induced lysosomal storage pathologies. The presence of the chitobiase corresponds to the occurrence of one GlcNAc unit at the reducing end of stored oligosaccharides, while the absence of this glycosidase yields fragments with an intact GlcNAcβ- d-(1–4)GlcNAc moiety. These results verify our previous proposal that lysosomal disassembly of glycoproteins to free amino acids and sugars is an ordered, bidirectional pathway in which chitobiase (when present) catalyzes the last step during digestion of the protein-oligosaccharide linkage region.

Hydrazinolysis- N-reacetylation of glycopeptides and glycoproteins. Model studies using 2-acetamido-1- N-( l-aspart-4-oyl)-2-deoxy-β- d-glucopyranosylamine

2-Acetamido-1- N-( l-aspart-4-oyl)-2-deoxy-β- d-glucopyranosylamine (1) was used as a model glycopeptide to study the hydrazinolysis- N-reacetylation procedure. The major, initial product was the β-acetohydrazide derivative of 2-acetamido-2-deoxy- d-glucose (2) which gave 2-acetamido-2-deoxy- d-glucose (5) after exposure to acidic conditions. Very mild conditions of hydrolysis of 2 gave a 75–80% overall yield of 5 from 1 after the hydrazinolysis- N-reacetylation procedure. Several other minor compounds were detected which were not converted into 5 upon mild acid hydrolysis, indicating that 20–25% of product cannot be recovered as 5 at the reducing end of oligosaccharides.

Preparation and β-elimination of a 5-deoxy-5-nitromaltitol derivative: an approach to selective cleavage of the glycosidic bond at the reducing end of oligosaccharides

Preparation and β-elimination of a 5-deoxy-5-nitromaltitol derivative: an approach to selective cleavage of the glycosidic bond at the reducing end of oligosaccharides