9- O-acetylated sialic acids enhance entry of virulent Leishmania donovani promastigotes into macrophages.

SUMMARY: Distribution of 9-O-acetylated sialic acids (9-O-AcSA) on Leishmania donovani has been previously reported. Considering their role in recognition, the differential distribution of sialic acids especially 9-O-acetylated sialic acids in avirulent (UR6) versus virulent (AG83 and GE1) promastigotes of Leishmania donovani and its role in entry into macrophages was explored. Fluorimetric-HPLC, fluorimetric determination and ELISA revealed 14-, 8- and 5-fold lower sialic acids in UR6 as compared to AG83. Interestingly, on UR6, flow cytometry indicated lower (alpha2-->6)-linked sialoglycoproteins along with minimal 9-O-acetylated sialoglycoproteins by Scatchard analysis. Further, UR6 demonstrated a 9- and 14.5-fold lower infectivity and phagocytic index than AG83. Additionally, de-O-acetylation and de-sialylation of AG83 demonstrated a 3- and 1.5-fold reduced phagocytic index. The role of 9-O-AcSA in entry was further confirmed by pre-blocking the macrophage surface with a cocktail of sugars followed by microscopic quantification. The phagocytic index of AG83 exclusively through 9-O-AcSA was significantly high. Interestingly, AG83 produced higher metacyclic promastigotes containing increased 9-O-AcSA as compared to avirulent UR6 supporting its virulent nature. Taken together; our results conclusively demonstrate the increased presence of 9-O-acetylated sialic acid on promastigotes of virulent Leishmania donovani as compared to avirulent UR6 and their subsequent role in entry within macrophages.

Monosialylated biantennary N-glycoforms containing GalNAc-GlcNAc antennae predominate when human EPO is expressed in goat milk.

Recently, our group reported the expression of recombinant human erythropoietin in goat milk (rhEPO-milk) as well as in the mammary epithelial cell line GMGE (EPO-GMGE) by cell culture using the adenoviral transduction system. N-Glycosylation characterization of rhEPO-milk by Normal-Phase HPLC profiling of the fluorophore, 4-aminobenzoic acid-labeled enzymatically released N-glycan pool from rhEPO-goat milk, combined with MALDI, ESI-MS and LC/MS, revealed that low branched, core-fucosylated, N-glycans predominate. The labeled N-glycans were separated into neutral and charged fractions by anion exchange chromatography and the charged N-glycans were found to be mostly alpha2,6-monosialylated with Neu5Ac or Neu5Gc in a ratio of 1:1. Unlike the N-glycans from rhEPO produced in CHO cells, where the glycans are multiantennary highly sialylated, core-fucosylated oligosaccahrides, or even in the goat mammary gland epithelial cell line cultured in vitro in which multiantennary, core- and outer-arm fucosylated, monosialylated N-glycans are the most abundant species, a large proportion of the N-glycans from rhEPO-milk were monosialylated, biantennary, antennae mostly terminating with the more unusual GalNAc-GlcNAc motive and without outer-arm fucosylation. These findings, emphasizing the difference in the N-glycan repertoire between the rhEPO-milk and EPO-GMGE, are consistent with the principle that glycosylation is cell-type dependent and that the cell environment is crucial as well.

The goat mammary glandular epithelial (GMGE) cell line promotes polyfucosylation and N,N'-diacetyllactosediaminylation of N-glycans linked to recombinant human erythropoietin.

We have established a continuous, non-transformed cell line from primary cultures from Capra hircus mammary gland. Low-density cultures showed a homogeneous epithelial morphology without detectable fibroblastic or myoepithelial cells. The culture was responsive to contact inhibition of proliferation and its doubling time was dependent on the presence of insulin and epidermal growth factor (EGF). GMGE cells secrete caseins regardless of the presence or absence of lactogenic hormones in the culture media. Investigation of the total N-glycan pool of human erythropoietin (rhEPO) expressed in GMGE cells by monosaccharide analysis, HPLC profiling, and mass spectrometry, indicated significant differences with respect to the same protein expressed in Chinese hamster ovary (CHO) cells. N-Glycans of rhEPO-GMGE are core-fucosylated, but fucosylation of outer arms was also found. Our results also revealed the presence of low levels of sialylation (>95% Neu5Ac), N,N'-diacetyllactosediamine units, and possibly Gal-Gal non-reducing terminal elements.

Immunodiagnostically applicable monoclonal antibodies to the circulating anodic antigen of Schistosoma mansoni bind to small, defined oligosaccharide epitopes.

Gut-associated glycoproteins constitute a major group of the circulating excretory antigens produced by human Schistosoma species. The O-glycans of the relatively abundant circulating anodic antigen (CAA) from S. mansoni carry long stretches of unique -->6(GlcA beta 1-->3)GalNAc beta 1--> repeats. Specific anti-carbohydrate monoclonal antibodies (mAbs) are essential tools for the immunodiagnostic detection of CAA in the serum or urine of Schistosoma-infected subjects. In order to define the epitopes recognised by these anti-CAA mAbs, we screened a series of protein-coupled synthetic di- to pentasaccharide building blocks of the CAA polysaccharide for immunoreactivity, using ELISA and surface plasmon resonance spectroscopy. It was shown that anti-CAA IgM mAbs preferentially recognise -->6(GlcA beta 1-->3)GalNAc beta 1--> disaccharide units. Interestingly, no mouse anti-CAA mAbs of the IgG class were found that bind to the synthetic epitopes, although many of the IgG mAbs tested do recognise native CAA in a carbohydrate-dependent manner. In addition, both IgM and IgG class antibodies could be detected in human infection sera using the synthetic CAA fragments. These synthetic schistosome glycan epitopes and their matching set of specific mAbs are useful tools that further the development of diagnostic methods and are helpful in defining the immunological responses of the mammalian hosts to schistosome glycoconjugates.

Dominant antibody responses to Fucalpha1-3GalNAc and Fucalpha1-2Fucalpha1-3GlcNAc containing carbohydrate epitopes in Pan troglodytes vaccinated and infected with Schistosoma mansoni.

The development of the humoral anti-glycan immune response of chimpanzees, either or not vaccinated with radiation-attenuated Schistosoma mansoni cercariae, was followed during 1 year after infection with S. mansoni. During the acute phase of infection both the vaccinated and the control chimpanzees produce high levels of immunoglobulin G (IgG) antibodies against carbohydrate structures that are characteristic for schistosomes carrying the Fucalpha1-3GalNAc and Fucalpha1-2Fucalpha1-3GlcNAc motifs, but not to the more widespread occurring structures GalNAcbeta1-4GlcNAc, GalNAcbeta1-4(Fucalpha1-3)GlcNAc, and Galbeta1-4(Fucalpha1-3)GlcNAc (Lewis(x)). In addition, high levels of IgM antibodies were found against the trimeric Lewis(x) epitope. Apparently, the schistosome-characteristic carbohydrate structures are dominant epitopes in the anti-glycan humoral immune response of the chimpanzees. All chimpanzees showed an increase in the level of antibodies against most of the carbohydrate structures tested directly after vaccination, peaking at challenge time and during the acute phase of infection. With the exception of anti-F-LDN antibody responses, the anti-carbohydrate antibody responses upon schistosome infection of the vaccinated animals were muted in comparison to the control animals.

Synthesis of Streptococcus pneumoniae type 3 neoglycoproteins varying in oligosaccharide chain length, loading and carrier protein.

The preparation is described of a range of neoglycoproteins containing synthesised fragments of the capsular polysaccharide of Streptococcus pneumoniae type 3, that is beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->O)-(CH2)3NH2 (1), beta-D-Glcp-(1-->3)-beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->O)-(CH2)3NH2 (2), and beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->3)-beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->O)-(CH4)NH2 (3). A blockwise approach was developed for the synthesis of the protected carbohydrate chains, in which the carboxylic groups were introduced prior to deprotection by selective oxidation of HO-6 in the presence of HO-4 by using TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy radical). After deprotection, the 3-aminopropyl spacer of the fragments was elongated with diethyl squarate (3,4-diethoxy-3-cyclobutene-1,2-dione) and the elongated oligosaccharides were conjugated to CRM197 (cross-reacting material of diphtheria toxin), KLH (keyhole limpet hemocyanin) or TT (tetanus toxoid). The resulting neoglycoconjugates varied in oligosaccharide chain length, oligosaccharide loading and protein carrier. These well-defined conjugates are ideal probes for evaluating the influence of the different structural parameters in immunological tests.

Analysis of the interaction between lectins and tetra- and tri-saccharide mimics of the Sd(a) determinant by surface plasmon resonance detection.

The binding properties of a spacer-linked synthetic Sd(a) tetrasaccharide beta-D-GalpNAc-(1-->4)-alpha-Neu5Ac-(2-->3)]-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)-(CH(2))(5)-NH(2) (1), two tetrasaccharide mimics beta-D-Galp-(1-->4)-alpha-Neu5Ac-(2-->3)]-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)-(CH(2))(5)-NH(2) (2) and beta-D-GlcpNAc-(1-->4)-alpha-Neu5Ac-(2-->3)]-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)-(CH(2))(5)-NH(2) (3), and two trisaccharide mimics beta-D-GalpNAc-(1-->4)-3-O-(SO(3)H)-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)-(CH(2))(5)-NH(2) (4) and beta-D-GalpNAc-(1-->4)-3-O-(CH(2)COOH)-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)-(CH(2))(5)-NH(2) (5) with lectins from Dolichos biflorus (DBL), Maackia amurensis (MAL), Phaseolus limensis (PLL), Ptilota plumosa (PPL), Ricinus communis 120 (RCL120) and Triticum vulgaris (wheat germ agglutinin, WGA) have been investigated by surface plasmon resonance (SPR) detection. MAL, PPL, RCL120 and WGA did not display any binding activity with compounds 1-5. However, DBL and PLL, both exhibiting GalNAc-specificity, showed strong binding activity with compounds 1, 4 and 5, and 1, 3, 4 and 5, respectively. The results demonstrate that SPR is a very useful analysis system for identifying biologically relevant oligosaccharide mimics of the Sd(a) determinant.

Carbohydrate self-recognition mediates marine sponge cellular adhesion.

Sponges (Porifera), the simplest and earliest multicellular organisms, are thought to have evolved from their unicellular ancestors about 1 billion years ago by developing cell-recognition and adhesion mechanisms to discriminate against "non-self." Consequently, they are used as models for investigating recognition phenomena. Cellular adhesion of marine sponges is an event involving adherence of extracellular proteoglycan-like molecules, otherwise known as aggregation factors (AFs). In a calcium-independent process the AFs adhere to the cell surface, and in a calcium-dependent process they exhibit AF self-association. A mechanism which has been implied but not definitely proven to play a role in the calcium-dependent event is self-recognition of defined carbohydrate epitopes. For the red beard sponge, Microciona prolifera, two carbohydrate epitopes, a sulfated disaccharide and a pyruvylated trisaccharide, have been implicated in cellular adhesion. To investigate this phenomenon a system has been designed, by using surface plasmon resonance detection, to mimic the role of carbohydrates in cellular adhesion of M. prolifera. The results show self-recognition of the sulfated disaccharide to be a major force behind the calcium-dependent event. The interaction is not simply based on electrostatic interactions, as other sulfated carbohydrates analyzed by using this procedure did not self-associate. Furthermore, the interaction is completely eradicated on substitution of Ca(2+) ions by either Mg(2+) or Mn(2+) ions. This physiologically relevant recognition mechanism confirms the existence of true carbohydrate self-recognition, and may have significant implications for the role of carbohydrates in cellular recognition of higher organisms.

Synthetic polysaccharide type 3-related di-, tri-, and tetrasaccharide-CRM(197) conjugates induce protection against Streptococcus pneumoniae type 3 in mice.

Di-, tri-, and tetrasaccharides, synthesized according to the chemical structure of pneumococcal polysaccharide type 3 (PS3), were coupled to the cross-reactive material (CRM(197)) of modified diphtheria toxin in different molar carbohydrate/protein ratios using the squarate coupling method. To study protective immunity, female BALB/c mice were subcutaneously immunized twice (with a 3-week interval) using the amount of conjugates corresponding to 2.5 microg of oligosaccharide per mouse. The conjugates evoked PS3 binding immunoglobulin G antibodies that lasted for at least 7 weeks after the booster. Immunogenicity was not influenced by the carbohydrate/protein ratio. All mice with PS3-specific antibodies survived the intraperitoneal challenge with Streptococcus pneumoniae type 3. Therefore, synthetic oligosaccharide-protein conjugates might have potential as vaccines.

Analysis of Asn-linked glycans from vegetable foodstuffs: widespread occurrence of Lewis a, core alpha1,3-linked fucose and xylose substitutions.

The N-glycans from 27 "plant" foodstuffs, including one from a gymnospermic plant and one from a fungus, were prepared by a new procedure and examined by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). For several samples, glycan structures were additionally investigated by size-fractionation and reverse-phase high-performance liquid chromatography in conjunction with exoglycosidase digests and finally also (1)H-nuclear magnetic resonance spectroscopy. The glycans found ranged from the typical vacuolar "horseradish peroxidase" type and oligomannose to complex Le(a)-carrying structures. Though the common mushroom exclusively contained N-glycans of the oligomannosidic type, all plant foods contained mixtures of the above-mentioned types. Apple, asparagus, avocado, banana, carrot, celery, hazelnut, kiwi, onion, orange, pear, pignoli, strawberry, and walnut were particularly rich in Le(a)-carrying N-glycans. Although traces of Le(a)-containing structures were also present in almond, pistachio, potato, and tomato, no such glycans could be found in cauliflower. Coconut exhibited almost exclusively N-glycans containing only xylose but no fucose. Oligomannosidic N-glycans dominated in buckwheat and especially in the legume seeds mung bean, pea, peanut, and soybean. Papaya presented a unique set of hybrid type structures partially containing the Le(a) determinant. These results are not only compatible with the hypothesis that the carbohydrate structures are another potential source of immunological cross-reaction between different plant allergens, but they also demonstrate that the Le(a)-type structure is very widespread among plants.

Structure of the exopolysaccharide produced by Streptococcus thermophilus S3.

The exopolysaccharide of Streptococcus thermophilus S3, produced in skimmed milk, is composed of D-galactose and L-rhamnose in a molar ratio of 2:1. The polysaccharide contains 0.4 equiv of O-acetyl groups per repeating unit. Linkage analysis and 1D/2D NMR (1H and 13C) studies on native and O-deacetylated EPS together with nanoES-CID tandem mass spectrometry studies on oligosaccharides generated by a periodate oxidation protocol, show the polysaccharide to have the following structure: [structure: see text].

Structure of the extracellular polysaccharide produced by Lactobacillus delbrueckii subsp. bulgaricus 291.

The lactic acid bacterium Lactobacillus delbrueckii subsp. bulgaricus 291, when grown in skimmed milk, produced 80 mg/L exopolysaccharide with an average molecular mass of 1.4 x 10(3) kDa. Monosaccharide analysis, methylation analysis, MS, and 1D/2D NMR (1H and 13C) studies performed on the native polysaccharide, and on oligosaccharides obtained from a mild acid hydrolysate of the native polysaccharide, showed the polysaccharide to consist of branched pentasaccharide repeating units with the following structure: [structure: see text].

Synthesis of nucleotide-activated oligosaccharides by beta-galactosidase from Bacillus circulans.

The enzymatic access to nucleotide-activated oligosaccharides by a glycosidase-catalyzed transglycosylation reaction was explored. The nucleotide sugars UDP-GlcNAc and UDP-Glc were tested as acceptor substrates for beta-galactosidase from Bacillus circulans using lactose as donor substrate. The UDP-disaccharides Gal(beta1-4)GlcNAc(alpha1-UDP) (UDP-LacNAc) and Gal(beta1-4)Glc(alpha1-UDP) (UDP-Lac) and the UDP-trisaccharides Gal(beta1-4)Gal(beta1-4)GlcNAc(alpha1-UDP and Gal(beta1-4)Gal(beta1-4)Glc(alpha1-UDP) were formed stereo- and regioselectively. Their chemical structures were characterized by 1H and 13C NMR spectroscopy and fast atom bombardment mass spectrometry. The synthesis in frozen solution at -5 degrees C instead of 30 degrees C gave significantly higher product yields with respect to the acceptor substrates. This was due to a remarkably higher product stability in the small liquid phase of the frozen reaction mixture. Under optimized conditions, at -5 degrees C and pH 4.5 with 500 mM lactose and 100 mM UDP-GlcNAc, an overall yield of 8.2% (81.8 micromol, 62.8 mg with 100% purity) for Gal(beta1-4)GlcNAc(alpha1-UDP) and 3.6% (36.1 micromol, 35 mg with 96% purity) for Gal(beta1-4)Gal(beta1-4)GlcNAc(alpha1-UDP) was obtained. UDP-Glc as acceptor gave an overall yield of 5.0% (41.3 micromol, 32.3 mg with 93% purity) for Gal(beta1-4)Glc(alpha1-UDP) and 1.6% (13.0 micromol, 12.2 mg with 95% purity) for Gal(beta1-4)Gal(beta1-4)Glc(alpha1-UDP). The analysis of other nucleotide sugars revealed UDP-Gal, UDP-GalNAc, UDP-Xyl and dTDP-, CDP-, ADP- and GDP-Glc as further acceptor substrates for beta-galactosidase from Bacillus circulans.

Structure and properties of the exopolysaccharide produced by Streptococcus macedonicus Sc136.

Streptococcus macedonicus is a Gram positive lactic acid bacterium that is part of the starter flora present in Greek sheep and goat cheeses. The S. macedonicus Sc136 strain produces a high-molecular-mass, highly texturizing exopolysaccharide composed of D-glucose, D-galactose, and N-acetyl-D-glucosamine in the molar ratio of 3:2:1. The structure of the exopolysaccharide produced by S. macedonicus Sc136 was determined by chemical analysis, mass spectrometry, and nuclear magnetic resonance spectroscopy. The repeating unit was shown to be: (see text) The polysaccharide sidechain beta-D-Galf-(1-->6)-beta-D-Glcp-(1-->6)-beta-D-GlcpNAc is a key factor in the highly texturizing properties of the S.macedonicus Sc136 exopolysaccharide. Finally, the trisaccharide sequence beta-D-GlcpNAc-(1-->3)-beta-D-Galp-(1-->4)-beta-D-Glcp corresponds to the internal backbone of the lacto-N-tetraose and lacto-N-neotetraose units, which serve as a structural basis for the large majority of human milk oligosaccharides, an additional property offering an important potential for the development of improved infant nutrition products.

Synthetic 6B di-, tri-, and tetrasaccharide-protein conjugates contain pneumococcal type 6A and 6B common and 6B-specific epitopes that elicit protective antibodies in mice.

The immunogenicity and protective capacity of Streptococcus pneumoniae 6B capsular polysaccharide (PS)-derived synthetic phosphate-containing disaccharide (Rha-ribitol-P-), trisaccharide (ribitol-P-Gal-Glc-), and tetrasaccharide (Rha-ribitol-P-Gal-Glc-)-protein conjugates in rabbits and mice were studied. In rabbits, all saccharides conjugated to keyhole limpet hemocyanin (KLH) evoked high levels of pneumococcal (Pn) type 6B antibodies that facilitated type-specific phagocytosis. Unlike the disaccharide rabbit antisera, tri- and tetrasaccharide rabbit antisera also reacted with 6A PS in an enzyme-linked immunosorbent assay (ELISA) and promoted phagocytosis of 6A pneumococci. All these rabbit antisera passively protected mice against a Pn 6B challenge. The disaccharide conjugate-induced antiserum, however, failed to protect mice against a 6A challenge. In mice, phagocytic and protective anti-Pn 6B antibodies were only induced by the tetrasaccharide conjugate and not by PS 6B or PS 6B-protein conjugates. These antibodies did not cross-react with 6A PS in ELISA and were unable to phagocytize 6A pneumococci. In conclusion, the disaccharide and tetrasaccharide conjugates already contain epitopes capable of inducing 6B-specific, fully protective antibodies in rabbits and mice, respectively.

The CDTA-soluble pectic substances from soybean meal are composed of rhamnogalacturonan and xylogalacturonan but not homogalacturonan.

Structural characteristics of pectic substances extracted from soybean meal cell walls (water unextractable solids) with a chelating agent-containing buffer (0.05M 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CDTA) and 0.05M NH(4)-oxalate in 0.05M NaOAc buffer) were studied. The arabinogalactans present as side chains to the rhamnogalacturonan backbone were largely removed by enzymatic hydrolysis using endo-galactanase, exo-galactanase, endo-arabinanase, and arabinofuranosidase B. The remaining pectic backbone appeared to be resistant to enzymatic degradation by pectolytic enzymes. After partial acid hydrolysis of the isolated pectic backbone, one oligomeric and two polymeric populations were obtained by size-exclusion chromatography. Monosaccharide and linkage analyses, enzymatic degradation, and NMR spectroscopy of these populations showed that the pectic substances in the original extract contain both rhamnogalacturonan and xylogalacturonan regions, while homogalacturonan is absent.

The patterns of the complex- and oligomannose-type glycans of uromodulin (Tamm-Horsfall glycoprotein) in the course of pregnancy.

Uromodulin was isolated from urine of three pregnant women. Urine of each donor was collected at subsequent stages of their pregnancy and at one month after gestation. Each batch of uromodulin was enzymatically N-deglycosylated and the released N-glycans were isolated, quantified and profiled by high-pH anion-exchange chromatography. In the course of pregnancy no significant changes were detected in the negative charge distribution stemming from sialic acid and sulfate residues on the complex-type carbohydrate chains of uromodulin. Furthermore, no significant changes in the molar ratio between Man6GlcNAc2 and Man7GlcNAc2 were found in the course of pregnancy, only uromodulin from non-pregnant periods showed small differences.

FAB CIDMS/MS analysis of partially methylated maltotrioses derived from methylated amylose: a study of the substituent distribution.

Amylose was methylated with CH3I in alkaline aqueous suspension, yielding methylated amylose (MeAl) with a degree of substitution of 1.44 (s < 0.01). Determination of the monomer composition showed that HO-6 and HO-2 were highly substituted in contrast to HO-3 (7:2:5.5, HO-2:HO-3:HO-6). By using partial acid hydrolysis, oligomers were prepared that varied both in degree of polymerisation and in methyl-content. Studies on the distribution of substituents in trimers showed large deviations from random distributions. By using CID tandem mass spectrometry, the substituent distribution in these trimers was determined in more detail. Various sets of trimers with equal amounts of methyl-groups but differing in substituted positions were quantified. From the monomer composition of MeAl, the probability of each trimer was calculated and compared to the outcome of the measured distributions. It was concluded that trimers with terminal tri- or non-substituted glucose monomers at the non-reducing end were formed preferentially during partial hydrolysis and that partial hydrolysis of MeAl yielded oligomers in a non-random way. This is the first study that describes the partial hydrolysis of MeAl in such detail.

Studies on the structure of a lithium-treated soybean pectin: characteristics of the fragments and determination of the carbohydrate substituents of galacturonic acid.

Two galacturonic-acid-containing polysaccharide fractions (ChSS and P) were isolated from soybean meal and subjected to lithium treatment. The fragments obtained were analyzed by using monosaccharide and methylation analyses, and NMR spectroscopy. Lithium degradation of ChSS, followed by sodium borodeuteride reduction, hydrolysis, sodium borohydride reduction, and acetylation afforded alditol acetates, of which the labeled ones reflected residues linked to GalA. As followed from quantifications of the labeled and non-labeled alditols from each constituent monosaccharide by GLC-EIMS, 6 mol% of Ara, 22 mol% of Fuc, 13 mol% of Gal, 53 mol% of Rha, and 57 mol% of Xyl are glycosidically linked to GalA. Analysis of the lithium-treated polymer revealed that it contains arabinogalactan side chains linked to Rha O-4, which consist of a beta-(1 --> 4)-linked galactan substituted with highly branched arabinan chains. On average, an arabinogalactan chain contains up to 29 Gal and 25 Ara residues. Surface plasmon resonance was used to determine conditions for affinity chromatography. Furthermore, this technique confirmed the presence of terminal alpha-Fuc residues in ChSS. Polysaccharide P turned out to be relatively resistant to lithium degradation.

CP-MAS NMR analysis of carbohydrate fractions of soybean hulls and endosperm.

CP-MAS NMR spectroscopy was used to identify soybean cellulose and pectin extracts and to investigate the kinetics of cross polarization. The in vitro incubation of cellulose and pectin, extracted from soya hull and endosperm, respectively, with sheep rumen fluid was followed with this technique. The difference in enzymatic degradability between ChSS and DASS, two pectins with identical monosaccharide composition, was explained by the degree of esterification that is lower in DASS. Variable contact time CP-MAS NMR experiments of the cellulose fraction during the incubation revealed that cellulose was degraded in a layer-by-layer way.