Journal articles: 'Oligosaccharide Synthesi'

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Fan, Jing, Jiayi Chen, Haochen Wu, Xin Lu, Xibi Fang, Fuquan Yin, Zhihui Zhao, Ping Jiang, and Haibin Yu. "Chitosan Oligosaccharide Inhibits the Synthesis of Milk Fat in Bovine Mammary Epithelial Cells through AMPK-Mediated Downstream Signaling Pathway." Animals 12, no. 13 (June 30, 2022): 1692. http://dx.doi.org/10.3390/ani12131692.

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Chitosan oligosaccharide (COS) is a variety of oligosaccharides, and it is also the only abundant basic amino oligosaccharide in natural polysaccharides. Chitosan oligosaccharide is a low molecular weight product of chitosan after enzymatic degradation. It has many biological effects, such as lipid-lowering, antioxidant and immune regulation. Previous studies have shown that chitosan oligosaccharide has a certain effect on fat synthesis, but the effect of chitosan oligosaccharide on milk fat synthesis of bovine mammary epithelial cells (BMECs) has not been studied. Therefore, this study aimed to investigate chitosan oligosaccharide’s effect on milk fat synthesis in bovine mammary epithelial cells and explore the underlying mechanism. We treated bovine mammary epithelial cells with different concentrations of chitosan oligosaccharide (0, 100, 150, 200, 400 and 800 μg/mL) for 24 h, 36 h and 48 h respectively. To assess the effect of chitosan oligosaccharide on bovine mammary epithelial cells and determine the concentration and time for chitosan oligosaccharide treatment on cells, several in vitro cellular experiments, including on cell viability, cycle and proliferation were carried out. The results highlighted that chitosan oligosaccharide (100, 150 μg/mL) significantly promoted cell viability, cycle and proliferation, increased intracellular cholesterol content, and reduced intracellular triglyceride and non-esterified fatty acids content. Under the stimulation of chitosan oligosaccharide, the expression of genes downstream of Phosphorylated AMP-activated protein kinase (P-AMPK) and AMP-activated protein kinase (AMPK) signaling pathway changed, increasing the expression of peroxisome proliferator-activated receptor alpha (PPARα) and hormone-sensitive lipase (HSL), but the expression of sterol regulatory element-binding protein 1c (SREBP1) and its downstream target gene stearoyl-CoA desaturase (SCD1) decreased. In conclusion, these results suggest that chitosan oligosaccharide may inhibit milk fat synthesis in bovine mammary epithelial cells by activating the AMP-activated protein kinase signaling pathway, promoting the oxidative decomposition of fatty acids and inhibiting fatty acid synthesis.

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Gong, Mengge, Tiechuan Li, Lina Wu, Zhenxing Zhang, Lishi Ren, Xuexin Duan, Hongzhi Cao, Meishan Pei, Jian-Jun Li, and Yuguang Du. "Liquid-Phase and Ultrahigh-Frequency-Acoustofluidics-Based Solid-Phase Synthesis of Biotin-Tagged 6′/3′-Sialyl-N-Acetylglucosamine by Sequential One-Pot Multienzyme System." Catalysts 10, no. 11 (November 19, 2020): 1347. http://dx.doi.org/10.3390/catal10111347.

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6′/3′-Sialylated N-acetyllactosamine (6′/3′-SLN) is important for discrimination of the source (human or avian) of influenza virus strains. Biotinylated oligosaccharides have been widely used for analysis and quick detection. The development of efficient strategies to synthesize biotin-tagged 6′/3′-SLN have become necessary. Effective mixing is essential for enzymatic solid-phase oligosaccharide synthesis (SPOS). In the current study, newly developed technology ultrahigh-frequency-acoustofluidics (UHFA), which can provide a powerful source for efficient microfluidic mixing, solid-phase oligosaccharide synthesis and one-pot multienzyme (OPME) system, were used to develop a new strategy for oligosaccharide synthesis. Firstly, biotinylated N-acetylglucosamine was designed and chemically synthesized through traditional approaches. Secondly, biotinylated 6′- and 3′-sialyl-N-acetylglucosamines were prepared in solution through two sequential OPME modules in with a yield of ~95%. Thirdly, 6′-SLN was also prepared through UHFA-based enzymatic solid-phase synthesis on magnetic beads with a yield of 64.4%. The current strategy would be potentially used for synthesis of functional oligosaccharides.

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Whitfield, Dennis M., Henrianna Pang, Jeremy P. Carver, and Jiri J. Krepinsky. "Syntheses of model oligosaccharides of biological significance. X.•Syntheses and NMR and mass spectral analysis of trideuteriomethyl di-3,6-O-(4-O-β-D-galactopyranosyl-2-acetamido-2-deoxy-β-D-glucopyranosyl)-β-D-galactopyranoside: the I antigen branchpoint penta- and tetrasaccharides and a related trisaccharide." Canadian Journal of Chemistry 68, no. 6 (June 1, 1990): 942–52. http://dx.doi.org/10.1139/v90-147.

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As part of our studies of complex oligosaccharides, in particular their three-dimensional structure, we have synthesized the antigen I branchpoint penta- and tetrasaccharides. The unbranched trisaccharide 3D was also synthesized, and its derivative 3B served as the intermediate for the synthesis of higher oligosaccharides. NMR spectra of major intermediates as well as of the final oligosaccharides were completely assigned. Mass spectra of the synthetic intermediates and the final oligosaccharides were analyzed and compared with those of a similar group of oligosaccharides containing L-fucose, N-acetyl-D-glucosamine, and D-galactose. Certain observations were made that could be utilized in the interpretation of mass spectra for the structural determination of protected oligosaccharides during the synthesis. Keywords: oligosaccharide synthesis, I antigen, carbohydrate mass spectrometry, carbohydrate NMR spectrometry, Gal-GlcNAc oligomers.

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Villers, C., R. Cacan, A. M. Mir, O. Labiau, and A. Verbert. "Release of oligomannoside-type glycans as a marker of the degradation of newly synthesized glycoproteins." Biochemical Journal 298, no. 1 (February 15, 1994): 135–42. http://dx.doi.org/10.1042/bj2980135.

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The N-glycosylation of proteins is accompanied by the release of soluble oligosaccharide material. Besides oligosaccharide phosphates originating from the cleavage of lipid intermediates, neutral free oligosaccharides represent the major part of this material and are heterogeneous depending on whether the reducing end has one or two N-acetylglucosamine residues. The present study focuses on the intracellular origin of neutral free oligosaccharides in a CHO cell line. Kinetic and pulse-chase experiments clearly indicate that oligosaccharides possessing a chitobiosyl unit are derived from oligosaccharide pyrophosphodolichol, whereas oligosaccharides possessing one N-acetyl-glucosamine residue are derived from newly synthesized glycoprotein. This relationship is confirmed by comparing the glycosylation pattern of lipid donors and glycoproteins with those of neutral free oligosaccharides under various incubation conditions (inhibition of protein synthesis, presence of processing inhibitors, presence or absence of glucose). Degradation of newly synthesized glycoprotein and formation of neutral oligosaccharides with one N-acetylglucosamine residue are inhibited at 16 degrees C but not affected by lysosomotropic agents such as leupeptin or NH4Cl. Together with the fact that the degradation of newly synthesized glycoproteins and the subsequent release of the glycan are recovered in permeabilized cells, these results suggest that this phenomenon occurs in the rough endoplasmic reticulum or in a closely related compartment.

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DENYER, Kay, Darren WAITE, Anne EDWARDS, Cathie MARTIN, and Alison M. SMITH. "Interaction with amylopectin influences the ability of granule-bound starch synthase I to elongate malto-oligosaccharides." Biochemical Journal 342, no. 3 (September 5, 1999): 647–53. http://dx.doi.org/10.1042/bj3420647.

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This paper examines the properties in soluble form of two isoforms of starch synthase. One of these, granule-bound starch synthase I (GBSSI), is responsible for the synthesis of amylose inside the amylopectin matrix of the starch granule in vivo. The other, starch synthase II (SSII), is involved in amylopectin synthesis. Both isoforms can use amylopectin and malto-oligosaccharide as substrates in vitro. As well as acting as a substrate for GBSSI, amylopectin acts as an effector of this isoform, increasing the rate at which it elongates malto-oligosaccharides and promoting a processive rather than distributive mode of elongation of these compounds. The affinity of GBSSI for amylopectin as an effector is greater than its affinity for amylopectin as a substrate. The rate and mode of elongation of malto-oligosaccharides by SSII are not influenced by amylopectin. These results suggest that specific interaction with amylopectin in the matrix of the starch granule is a unique property of GBSSI and is critical in determining the nature of its products.

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Rabiu, Bodun A., Andrew J. Jay, Glenn R. Gibson, and Robert A. Rastall. "Synthesis and Fermentation Properties of Novel Galacto-Oligosaccharides by β-Galactosidases fromBifidobacterium Species." Applied and Environmental Microbiology 67, no. 6 (June 1, 2001): 2526–30. http://dx.doi.org/10.1128/aem.67.6.2526-2530.2001.

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ABSTRACT β-Galactosidase enzymes were extracted from pure cultures ofBifidobacterium angulatum, B. bifidum BB-12, B. adolescentis ANB-7, B. infantis DSM-20088, andB. pseudolongum DSM-20099 and used in glycosyl transfer reactions to synthesize oligosaccharides from lactose. At a lactose concentration of 30% (wt/wt) oligosaccharide yields of 24.7 to 47.6% occurred within 7 h. Examination of the products by thin-layer chromatography and methylation analysis revealed distinct product derived spectra from each enzyme. These were found to be different to that of Oligomate 55, a commercial prebiotic galacto-oligosaccharide. Fermentation testing of the oligosaccharides showed an increase in growth rate, compared to Oligomate 55, with products derived fromB. angulatum, B. bifidum, B. infantis, and B. pseudolongum. However B. adolescentis had a lower growth rates on its oligosaccharide compared with Oligomate 55. Mixed culture testing of the B. bifidum BS-4 oligosaccharide showed that the overall prebiotic effect was equivalent to that of Oligomate 55.

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Hamada, Hiroki, Hatsuyuki Hamada, Kohji Ishihara, Atsuhito Kuboki, Takafumi Iwaki, and Yuya Kiriake. "Enzymatic Synthesis of α-Tocopherol Derivative Glycoside, Daidzein Glycoside, Daidzein Oligosaccharide, Resveratrol Oligosaccharide, and Curcumin Oligosaccharides and Their Anti-Allergic Activity and Neuroprotective Activity." Natural Product Communications 16, no. 10 (October 2021): 1934578X2110290. http://dx.doi.org/10.1177/1934578x211029095.

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Enzymatic glycosylations of an α-tocopherol derivative, daidzein, resveratrol, and curcumin were investigated. The plant polyphenol, resveratrol, was incubated with glucosyltransferase from Phytolacca americana. The resveratrol glycoside obtained was then incubated with cyclodextrin glucanotransferase to obtain resveratrol oligosaccharide. Daidzein and curcumin were also converted into daidzein glycoside, daidzein oligosaccharide, and curcumin oligosaccharides. Also, α-tocopherol derivative, that is, 2, 5,7,8-tetramethyl-2-(4,8-dimethylnonyl)chroman-6-ol, was glycosylated. The glycosides and oligosaccharides had strong anti-allergic activity such as suppression of IgE formation, inhibition of histamine release, and inhibition of O2 - generation. In addition, the glycosides and oligosaccharides showed efficient neuroprotective activity by inhibition of phosphodiesterase.

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Bahar, Bojlul, John V. O'Doherty, and Torres Sweeney. "A potential role of IL-6 in the chito-oligosaccharide-mediated inhibition of adipogenesis." British Journal of Nutrition 106, no. 8 (May 18, 2011): 1142–53. http://dx.doi.org/10.1017/s0007114511001486.

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Recent studies have suggested that chito-oligosaccharides can have anti-adipogenic properties. The objectives of the present study were to evaluate the anti-adipogenic potential of four different chito-oligosaccharides (molecular weight (MW) < 1000, 1000–3000, 3000–5000 and 5000–10 000 Da) and to identify molecular mechanisms underlying the chito-oligosaccharide-mediated inhibition of adipogenesis. Mouse 3T3-L1 cells were allowed to differentiate in the presence of chito-oligosaccharide. At day 8 post-induction of differentiation, lipid accumulation, free glycerol release and the quantitative expression of adipogenic marker genes were evaluated. Chito-oligosaccharides had concentration- and MW-dependent inhibitory effects on lipid accumulation (P < 0·001 and < 0·05, respectively), as well as a concentration-dependent effect (P < 0·001) on free glycerol release and the expression of adipogenic marker genes. The 5000–10 000 Da chito-oligosaccharide was selected for subsequent molecular studies. A panel of forty-four lipid metabolic pathway-specific genes was analysed by quantitative real-time PCR. Chito-oligosaccharide-mediated inhibition of adipogenesis was associated with the up-regulation of theIL-6gene at all concentrations of chito-oligosaccharide examined and the PG-endoperoxide synthase 2 (PTGS2) gene at higher concentrations of chito-oligosaccharide. The effect of chito-oligosaccharide on gene expression was validated by measuring IL-6 protein concentrations in the media. Finally, anIL-6promoter assay was developed to characterise the effect of chito-oligosaccharide on the transcriptional activity of theIL-6promoter, which was increased in a concentration-dependent manner (P < 0·001). We conclude that IL-6 is a candidate signalling molecule in the chito-oligosaccharide-mediated inhibition of adipogenesis in 3T3-L1 cells.

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Hada, Noriyasu, Tokio Morita, Takashi Ueda, Kazuki Masuda, Hiromi Nakane, Mami Ogane, Kimiaki Yamano, Frank Schweizer, and Fumiyuki Kiuchi. "Synthesis of the Carbohydrate Moiety of Glycoproteins from the Parasite Echinococcus granulosus and Their Antigenicity against Human Sera." Molecules 26, no. 18 (September 17, 2021): 5652. http://dx.doi.org/10.3390/molecules26185652.

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Stereocontrolled syntheses of biotin-labeled oligosaccharide portions containing the carbohydrate moiety of glycoprotein from Echinococcus granulosus have been accomplished. Trisaccharide Galβ1-3Galβ1-3GalNAcα1-R (A), tetrasaccharide Galα1-4Galβ1-3Galβ1-3GalNAcα1-R (B), and pentasaccharide Galα1-4Galβ1-3Galβ1-3Galβ1-3GalNAcα1-R (C), (R = biotinylated probe) were synthesized by stepwise condensation and/or block synthesis by the use of 5-(methoxycarbonyl)pentyl 2-azido-4,6-O-benzylidene-2-deoxy-α-d-galactopyranoside as a common glycosyl acceptor. The synthesis of the tetrasaccharide and the pentasaccharide was improved from the viewpoint of reducing the number of synthetic steps and increasing the total yield by changing from stepwise condensation to block synthesis. Moreover, hexasaccharide E, which contains the oligosaccharide sequence which occurs in E. granulosus, was synthesized from trisaccharide D. We examined the antigenicity of these five oligosaccharides by an enzyme-linked immunosorbent assay (ELISA). Although compounds of C–E did not exhibit antigenicity against cystic echinococcosis (CE) patient sera, compounds B, D, and E showed good serodiagnostic potential for alveolar echinococcosis (AE).

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Yu, Dawei, Jiayao Feng, Huimin You, Shipeng Zhou, Yan Bai, Jincan He, Hua Cao, Qishi Che, Jiao Guo, and Zhengquan Su. "The Microstructure, Antibacterial and Antitumor Activities of Chitosan Oligosaccharides and Derivatives." Marine Drugs 20, no. 1 (January 13, 2022): 69. http://dx.doi.org/10.3390/md20010069.

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Chitosan obtained from abundant marine resources has been proven to have a variety of biological activities. However, due to its poor water solubility, chitosan application is limited, and the degradation products of chitosan oligosaccharides are better than chitosan regarding performance. Chitosan oligosaccharides have two kinds of active groups, amino and hydroxyl groups, which can form a variety of derivatives, and the properties of these derivatives can be further improved. In this review, the key structures of chitosan oligosaccharides and recent studies on chitosan oligosaccharide derivatives, including their synthesis methods, are described. Finally, the antimicrobial and antitumor applications of chitosan oligosaccharides and their derivatives are discussed.

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MOSI, Renee, and Stephen G. WITHERS. "Synthesis and kinetic evaluation of 4-deoxymaltopentaose and 4-deoxymaltohexaose as inhibitors of muscle and potato α-glucan phosphorylases." Biochemical Journal 338, no. 2 (February 22, 1999): 251–56. http://dx.doi.org/10.1042/bj3380251.

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α-Glucan phosphorylases degrade linear or branched oligosaccharides via a glycosyl transfer reaction, occurring with retention of configuration, to generate α-glucose-1-phosphate (G1P). We report here the chemoenzymic synthesis of two incompetent oligosaccharide substrate analogues, 4-deoxymaltohexaose (4DG6) and 4-deoxymaltopentaose (4DG5), for use in probing this mechanism. A kinetic analysis of the interactions of 4DG5 and 4DG6 with both muscle and potato phosphorylases was completed to provide insight into the nature of the binding mode of oligosaccharide to phosphorylase. The 4-deoxy-oligosaccharides bind competitively with maltopentaose and non-competitively with respect to orthophosphate or G1P in each case, indicating binding in the oligosaccharide binding site. Further, 4DG5 and 4DG6 were found to bind to potato and muscle phosphorylases some 10–40-fold tighter than does maltopentaose. Similar increases in affinity as a consequence of 4-deoxygenation were observed previously for the binding of polymeric glycogen analogues to rabbit muscle phosphorylase [Withers (1990) Carbohydr. Res. 196, 61–73].

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Kim, Minhui, Jae-Kweon Jang, and Young-Seo Park. "Production Optimization, Structural Analysis, and Prebiotic- and Anti-Inflammatory Effects of Gluco-Oligosaccharides Produced by Leuconostoc lactis SBC001." Microorganisms 9, no. 1 (January 19, 2021): 200. http://dx.doi.org/10.3390/microorganisms9010200.

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Leuconostoc lactis SBC001, isolated from chive, produces glucansucrase and synthesizes oligosaccharides through its enzymatic activity. This study was conducted to optimize oligosaccharide production using response surface methodology, analyze the structure of purified oligosaccharides, and investigate the prebiotic effect on 24 bacterial and yeast strains and the anti-inflammatory activity using RAW 264.7 macrophage cells. The optimal conditions for oligosaccharide production were a culture temperature of 30 °C and sucrose and maltose concentrations of 9.6% and 7.4%, respectively. Based on 1H-NMR spectroscopic study, the oligosaccharides were identified as gluco-oligosaccharides that consisted of 23.63% α-1,4 glycosidic linkages and 76.37% α-1,6 glycosidic linkages with an average molecular weight of 1137 Da. The oligosaccharides promoted the growth of bacterial and yeast strains, including Lactobacillus plantarum, L. paracasei, L. johnsonii, Leuconostoc mesenteroides, L. rhamnosus, and Saccharomyces cerevisiae. When lipopolysaccharide-stimulated RAW 264.7 cells were treated with the oligosaccharides, the production of nitric oxide was decreased; the expression of inducible nitric oxide synthase, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-10 was suppressed; and the nuclear factor-kappa B signaling pathway was inhibited. In conclusion, the gluco-oligosaccharides obtained from Leu. lactis SBC001 exhibited a prebiotic effect on six bacterial and yeast strains and anti-inflammatory activity in RAW 264.7 macrophage cells.

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Li, Feng Hong, Yong Sun, San Xi Li, and Shao Jun Ma. "Synthesis and Characterization of Thermoplastic Biomaterial Based on Acylated Chitosan Oligosaccharide." Applied Mechanics and Materials 117-119 (October 2011): 1433–36. http://dx.doi.org/10.4028/www.scientific.net/amm.117-119.1433.

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A series of acylated chitosan oligosaccharides (LCSOs) were synthesized by reacting chitosan oligosaccharide (CSO) with lauroyl chloride in methane sulfonic acid. The chemical structures of LCSOs were characterized by Fourier transform infrared. Differential scanning calorimetry (DSC) showed that LCSOs had two phase transitions during heating. Thermoplastic chitosan oligosaccharide (LCSO-4) has distinct melting temperature (Tm) at 64 °C and 110°C. X-ray diffraction (XRD) analyses indicated that the crystal structure of CSO was changed through acylation and had created new crystal domains of lauroyl side chains. New strong diffraction peaks were observed around 2θ values of 20.0°, 21.5° and 26.3° for thermoplastic acylated chitosan oligosaccharide (LCSO-4). The melting and crystallization properties of thermoplastic acylated chitosan oligosaccharide were observed by polarized optical microscope (POM).

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Jakeman, David L., and Stephen G. Withers. "On expanding the repertoire of glycosynthases: Mutant β-galactosidases forming β-(1,6)-linkages." Canadian Journal of Chemistry 80, no. 8 (August 1, 2002): 866–70. http://dx.doi.org/10.1139/v02-077.

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Oligosaccharide synthesis by enzymatic processes offers the potential for thrusting oligosaccharides to the forefront of pharmaceutical research, in part, due to expedient and scalable reaction protocols. Glycosynthases are an emerging class of mutant enzymes capable of synthesizing glycosidic linkages in high yield. We report a new glycosynthase enzyme generated by a point mutation of E. coli β-galactosidase that condenses α-galactosyl fluoride with aryl glucosides forming a β-(1,6) glycosidic linkage. A further point mutation within the enzyme, proximal to the active site, increases the yields significantly.Key words: glycosyl transfer, glycosynthase, enzymatic oligosaccharide synthesis. tétrahydrooxazine, isofagomine, iminosucres, inhibiteurs de glycosidases.[Traduit par la Rédaction]

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Cai, Zhi Peng, Wen Li Wang, Louis Conway, Kun Huang, Faisal Nureldin Awad, Li Liu, and Josef Voglmeir. "1,3-Di(2-dipyridyl)propan-1,3-dione – a new fluorogenic labeling reagent for milk oligosaccharides." Pure and Applied Chemistry 89, no. 7 (July 26, 2017): 921–29. http://dx.doi.org/10.1515/pac-2016-0914.

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Abstract:We herein demonstrate the use of 1,3-di(2-dipyridyl)propan-1,3-dione (DPPD) as a fluorogenic label for oligosaccharides. A number of milk-derived oligosaccharide standards were successfully labeled with this reagent, with the advantage of greatly simplified sample preparation compared to other commonly used fluorescent tags. DPPD shows a selectivity for oligosaccharides which do not possess a 2-acetamido-2-deoxy-hexose moiety at the reducing terminus, potentially aiding in the identification of complex mixtures of carbohydrates. The use of DPPD for the structural determination of oligosaccharides through exoglycosidase treatment, quantitative analysis of reactions, and in the synthesis of labeled oligosaccharides was also explored. This reagent has, in addition to the analysis of individual and mixed oligosaccharides, potential applications in the study of glycosidases and glycosyltransferases and as such represents a valuable addition to the tools available to the glycoscientist.

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WATTS, Andrew G., and Stephen G. WITHERS. "Glycosynthase-catalysed formation of modified polysaccharide microstructures." Biochemical Journal 380, no. 1 (May 15, 2004): e9-e10. http://dx.doi.org/10.1042/bj20040633.

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Glycosynthases are mutant glycosidases, genetically engineered to catalyse the synthesis of oligosaccharides. A study by Faijes et al. in this issue of the Biochemical Journal has expanded the ability of glycosynthases to catalyse the polymerization of carbohydrates to form unnatural oligosaccharide products that can attain unique crystalline forms. These findings reinforce the potential of glycosynthases as interesting and important tools for the enzymic synthesis of novel carbohydrates with specific and controlled structures.

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Malá, Š., P. Karasová, M. Marková, and B. Králová. "Oligosaccharide synthesis using a-glucosidases of different origin." Czech Journal of Food Sciences 19, No. 2 (February 7, 2013): 57–61. http://dx.doi.org/10.17221/6576-cjfs.

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a-Glucosidase from Aspergillus awamori and intestinal a-glucosidase (saccharase-isomaltase complex) exhibited high transglycosylation activity and were able to synthesize tri- and tetrasaccharides during maltose hydrolysis. Both tested enzymes were also able to transfer the glucose residue to all tested monosaccharide acceptors (D-mannose, D-xylose, L-sorbose and D-galactose). Their transfer activity towards respective acceptors varied and their acceptor preference also depended on the origin of the enzyme. Out of the acceptors tested, both enzymes exhibited high transfer activity in xylose.

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Beck, P. J., P. Orlean, C. Albright, P. W. Robbins, M. J. Gething, and J. F. Sambrook. "The Saccharomyces cerevisiae DPM1 gene encoding dolichol-phosphate-mannose synthase is able to complement a glycosylation-defective mammalian cell line." Molecular and Cellular Biology 10, no. 9 (September 1990): 4612–22. http://dx.doi.org/10.1128/mcb.10.9.4612-4622.1990.

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The Saccharomyces cerevisiae DPM1 gene product, dolichol-phosphate-mannose (Dol-P-Man) synthase, is involved in the coupled processes of synthesis and membrane translocation of Dol-P-Man. Dol-P-Man is the lipid-linked sugar donor of the last four mannose residues that are added to the core oligosaccharide transferred to protein during N-linked glycosylation in the endoplasmic reticulum. We present evidence that the S. cerevisiae gene DPM1, when stably transfected into a mutant Chinese hamster ovary cell line, B4-2-1, is able to correct the glycosylation defect of the cells. Evidence for complementation includes (i) fluorescence-activated cell sorter analysis of differential lectin binding to cell surface glycoproteins, (ii) restoration of Dol-P-Man synthase enzymatic activity in crude cell lysates, (iii) isolation and high-performance liquid chromatography fractionation of the lipid-linked oligosaccharides synthesized in the transfected and control cell lines, and (iv) the restoration of endoglycosidase H sensitivity to the oligosaccharides transferred to a specific glycoprotein synthesized in the DPM1 CHO transfectants. Indirect immunofluorescence with a primary antibody directed against the DPM1 protein shows a reticular staining pattern of protein localization in transfected hamster and monkey cell lines.

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Beck, P. J., P. Orlean, C. Albright, P. W. Robbins, M. J. Gething, and J. F. Sambrook. "The Saccharomyces cerevisiae DPM1 gene encoding dolichol-phosphate-mannose synthase is able to complement a glycosylation-defective mammalian cell line." Molecular and Cellular Biology 10, no. 9 (September 1990): 4612–22. http://dx.doi.org/10.1128/mcb.10.9.4612.

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The Saccharomyces cerevisiae DPM1 gene product, dolichol-phosphate-mannose (Dol-P-Man) synthase, is involved in the coupled processes of synthesis and membrane translocation of Dol-P-Man. Dol-P-Man is the lipid-linked sugar donor of the last four mannose residues that are added to the core oligosaccharide transferred to protein during N-linked glycosylation in the endoplasmic reticulum. We present evidence that the S. cerevisiae gene DPM1, when stably transfected into a mutant Chinese hamster ovary cell line, B4-2-1, is able to correct the glycosylation defect of the cells. Evidence for complementation includes (i) fluorescence-activated cell sorter analysis of differential lectin binding to cell surface glycoproteins, (ii) restoration of Dol-P-Man synthase enzymatic activity in crude cell lysates, (iii) isolation and high-performance liquid chromatography fractionation of the lipid-linked oligosaccharides synthesized in the transfected and control cell lines, and (iv) the restoration of endoglycosidase H sensitivity to the oligosaccharides transferred to a specific glycoprotein synthesized in the DPM1 CHO transfectants. Indirect immunofluorescence with a primary antibody directed against the DPM1 protein shows a reticular staining pattern of protein localization in transfected hamster and monkey cell lines.

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Lee, Ho Huat, Jose A. B. Baptista, and Jiri J. Krepinsky. "Syntheses of model oligosaccharides of biological significance. XI. A short synthesis of fucosylated chitobiosides, also bound to asparagine in a synthon (as in N-linked glycoproteins)." Canadian Journal of Chemistry 68, no. 6 (June 1, 1990): 953–57. http://dx.doi.org/10.1139/v90-148.

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We describe a simple and efficient method for the preparation of the trisaccharide GlcNAc(β1-4)-[Fuc(α 1-6)-]GlcNAc(β 1-) (1) and of the protected form of GlcNAc(β 1-4)-[Fuc(α 1-6)-]GlcNAc(β1-Asn) (2). The key intermediate is benzyl 4,6-benzylidene chitobioside 5 giving the desired trisaccharide by insitu anomerization–glycosylation reaction with 2,3,4-tribenzylfucosyl bromide. The benzyl glycoside in the trisaccharide 6 has been replaced by acetate and then bromine; this glycosylating agent was used to prepare methyl and 8-methoxycarbonyloctyl glycosides as well as isothiocyanate 12, in a series of reactions. The latter compound gave, on reaction with 1-benzyl N-benzyloxycarbonyl-L-asparate, compound 13 (a protected derivative of 2), which should serve as a synthon for syntheses of glycopeptides. Keywords: glycopeptide, synthesis; oligosaccharide, synthesis; chitobiosides; fucosylated chitobiosides; N-linked oligosaccharides.

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Monchois, Vincent, Augustin Reverte, Magali Remaud-Simeon, Pierre Monsan, and RenÃ¯Â¿Â½-Marc Willemot. "Effect of Leuconostoc mesenteroides NRRL B-512F Dextransucrase Carboxy-Terminal Deletions on Dextran and Oligosaccharide Synthesis." Applied and Environmental Microbiology 64, no. 5 (May 1, 1998): 1644–49. http://dx.doi.org/10.1128/aem.64.5.1644-1649.1998.

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ABSTRACT Dextransucrase (DSR-S) from Leuconostoc mesenteroidesNRRL B-512F is a glucosyltransferase that catalyzes synthesis of soluble dextran from sucrose. In the presence of efficient acceptor molecules, such as maltose, the reaction pathway is shifted toward glucooligosaccharide synthesis. Like glucosyltransferases from oral streptococci, DSR-S possesses a C-terminal glucan-binding domain composed of a series of tandem repeats. In order to determine the role of the C-terminal region of DSR-S in dextran or oligosaccharide synthesis, four DSR-S genes with deletions at the 3′ end were constructed. The results showed that the C-terminal region modulated the initial velocity of dextran synthesis but that theKm for sucrose, the optimum pH, and the activation energy were all unaffected by the deletions. The C-terminal domain modulated the rate of oligosaccharide synthesis whatever acceptor molecule was used (a good acceptor molecule such as maltose or a poor acceptor molecule such as fructose). The C-terminal domain seemed to play no role in the catalytic process in dextran and oligosaccharide synthesis. In fact, it seems that the role of the C-terminal domain of DSR-S may be to facilitate the translation of dextran and oligosaccharides from the catalytic site.

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Escamilla-Lozano, Yolanda, Francisco Guzmán-Rodríguez, Sergio Alatorre-Santamaría, Mariano García-Garibay, Lorena Gómez-Ruiz, Gabriela Rodríguez-Serrano, and Alma Cruz-Guerrero. "Synthesis of Fucosyl-Oligosaccharides Using α-l-Fucosidase from Lactobacillus rhamnosus GG." Molecules 24, no. 13 (June 29, 2019): 2402. http://dx.doi.org/10.3390/molecules24132402.

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Fucosyl-oligosaccharides are natural prebiotics that promote the growth of probiotics in human gut and stimulate the innate immune system. In this work, the release of α-lfucosidase by Lactobacillus rhamnosus GG, and the use of this enzyme for the synthesis of fucosyl-oligosaccharides were investigated. Since α-lfucosidase is a membrane-bound enzyme, its release from the cells was induced by addition of 4-nitrophenyl-α-l-fucopyranoside (pNP-Fuc). Enzyme activity associated with the cell was recovered at 78% of its total activity. Fucosyl-oligosaccharides where synthesized using α-l-fucosidase extract and pNP-Fuc as donor substrate, and D-lactose or D-lactulose as acceptor substrates, reaching a yield up to 25%. Fucosyllactose was obtained as a reaction product with D-lactose, and its composition was confirmed by mass spectrometry (MALDI-TOF MS). It is possible that the fucosyl-oligosaccharide synthesized in this study has biological functions similar to human milk oligosaccharides.

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Krylov, Vadim B., Lucia Paulovičová, Ema Paulovičová, Yury E. Tsvetkov, and Nikolay E. Nifantiev. "Recent advances in the synthesis of fungal antigenic oligosaccharides." Pure and Applied Chemistry 89, no. 7 (July 26, 2017): 885–98. http://dx.doi.org/10.1515/pac-2016-1011.

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AbstractThe driving force for the constant improvement and development of new synthetic methodologies in carbohydrate chemistry is a growing demand for biologically important oligosaccharide ligands and neoglycoconjugates thereof for numerous biochemical investigations such as cell-to-pathogen interactions, immune response, cell adhesion, etc. Here we report our syntheses of the spacer-armed antigenic oligosaccharides related to three groups of the polysaccharides of the fungal cell-wall including α- and β-mannan, α- and β-glucan and galactomannan chains, which include new rationally designed synthetic blocks, efficient solutions for the stereoselective construction of glycoside bonds, and novel strategy for preparation of furanoside-containing oligosaccharides based on recently discovered pyranoside-into-furanoside (PIF) rearrangement.

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24

Page, Kathleen Creed, Paul B. Mason, Lynn Lindstrom, James S. Swan, and Sally E. Nyquist. "Dolichol and N-linked oligosaccharide synthesis in the rat testis: interaction between Sertoli and spermatogenic cells, evidence for paracrine effects." Biochemistry and Cell Biology 70, no. 6 (June 1, 1992): 496–503. http://dx.doi.org/10.1139/o92-077.

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The relative contribution of the Sertoli cell and the pachytene spermatocyte to dolichol and N-linked oligosaccharide biosynthesis within the seminiferous tubule was investigated. Evidence is presented to show that the interaction between these two cell types affects dolichol and N-linked oligosaccharide biosynthesis. Analysis of the dolichol content of Sertoli cultures confirms earlier data suggesting that the Sertoli cell constitutes the major pool of dolichols within the seminiferous tubule. [14C]Acetate incorporation studies suggest that the Sertoli cell in culture synthesizes dolichol much more rapidly than does the isolated pachytene spermatocyte. This information, in addition to previous data in the literature, infers an interactive effect whereby the presence of the spermatogenic cell in the tubule stimulates dolichol synthesis in the Sertoli cell. The absence of normal Sertoli-spermatocyte interactions in in vitro incubations may also limit dolichol synthesis in the pachytene spermatocyte. The distribution of dolichol kinase between the Sertoli and the pachytene spermatocyte was also examined. The concentration of this enzyme in the Sertoli cell suggests the presence of an active salvage pathway within that cell. The correlation between the appearance of the pachytene spermatocyte and the previously described peak of dolichol kinase activity in the seminiferous tubules of the prepubertal animal implies cell–cell interactions. Radiolabelling studies of N-linked oligosaccharides were conducted using [3H]mannose and concanavalin A affinity chromatography to identify multiantennary, biantennary, and high-mannose oligosaccharide pools. An in vitro bicameral coculture system was used to demonstrate that pachytene spermatocytes stimulate incorporation of [3H]mannose into Sertoli cell oligosaccharides. The presence of spermatocytes also induced a shift of label from the multiantennary oligosaccharide pool to the high-mannose pool in the Sertoli cell. Reciprocal experiments, in which the pachytene spermatocyte oligosaccharide pools were observed, showed no significant changes. These studies show a clear pachytene spermatocyte derived paracrine effect on Sertoli cell glycosylation.Key words: glycoprotein, dolichol, Sertoli, spermatocyte.

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Nifantiev, N. E., A. A. Sherman, O. N. Yudina, P. E. Cheshev, Y. E. Tsvetkov, E. A. Khatuntseva, A. V. Kornilov, and A. S. Shashkov. "New schemes for the synthesis of glycolipid oligosaccharide chains." Pure and Applied Chemistry 76, no. 9 (September 30, 2004): 1705–14. http://dx.doi.org/10.1351/pac200476091705.

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The driving force for the constant improvement and development of synthetic methodologies in carbohydrate chemistry is the importance of natural oligosaccharide chains in numerous biological phenomena such as cell growth, differentiation, adhesion, etc. Here, we report our syntheses of the spacer-armed oligosaccharides of sialylated lacto- and neo- lacto-, globo-, ganglio-, and sulfoglucuronylparagloboside-series, which include new rationally designed synthetic blocks, efficient solutions for the stereoselective construction of glycosidic bonds, and novel protection group strategies.

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26

Osthoff, Gernot, Irenie Wiese, and Francois Deacon. "African Elephant Milk Short Saccharide and Metabolite Composition and Their Changes over Lactation." Animals 13, no. 3 (February 3, 2023): 544. http://dx.doi.org/10.3390/ani13030544.

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Elephant milk composition is unique, as are its changes over lactation. Presented here is the milk non-dedicated metabolite composition of three African elephants. Their lactation times are overlapping and span day one to thirty months. Metabolites were identified and quantified by 1H nuclear magnetic resonance spectroscopy. Lactose and short oligosaccharides are a large component of the metabolites, with lacto-N-difucohexaose I as the major oligosaccharide. These were followed by metabolites of lipids, amino acids, and the citric acid cycle. The content of lactose, lacto-N-difucohexaose I, 2′-fucosyllactose, and some unidentified oligosaccharides decrease over lactation, while that of difucosyllactose and other unidentified ones increase. The high content of glutamate, as a glucogenic amino acid, supported the uprated synthesis of saccharides by the milk gland cells. The content of succinate and choline increase over lactation, indicating higher energy expenditure and phospholipid synthesis during later lactation.

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27

María Espinosa, Rosa, Martha Taméz, and Pedro Prieto. "Efforts to emulate human milk oligosaccharides." British Journal of Nutrition 98, S1 (October 2007): S74—S79. http://dx.doi.org/10.1017/s0007114507838062.

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Research on human milk oligosaccharides (HMO) began with the characterisation of their chemical structures and is now focused on the elucidation of their biological roles. Previously, biological effects could only be investigated with fractions or structures isolated from breast milk; consequently, clinical observations were limited to comparisons between outcomes from breast-fed infants and their formula-fed counterparts. In some cases, it was inferred that the observed differences were caused by the presence of HMO in breast milk. Presently, analytical techniques allow for the fast analysis of milk samples, thus providing insights on the inherent variability of specimens. In addition, methods for the synthesis of HMO have provided single structures in sufficient quantities to perform clinical studies with oligosaccharide-supplemented formulae. Furthermore, studies have been conducted with non-mammalian oligosaccharides with the purpose of assessing the suitability of these structures to functionally emulate HMO. Taken together, these developments justify summarising current knowledge on HMO to further discussions on efforts to emulate human milk in regard to its oligosaccharide content. The present account summarises published data and intends to provide an historical context and to illustrate the state of the field.

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Fairweather, Jon K., Robert V. Stick, and Stephen G. Withers. "A 'Glycosynthase'-assisted Synthesis of Some Epoxyalkyl β-C-Oligosaccharides." Australian Journal of Chemistry 53, no. 12 (2000): 913. http://dx.doi.org/10.1071/ch00125.

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A series of alkenyl β-D-C-glucopyranosides has been glycosylated with α-D-glucopyranosyl fluoride in a ‘Glycosynthase’ reaction to yield a range of alkenyl β-C-cellobiosides and -triosides and in one case a -C-cellotetraoside. Conversion of some of the alkenyl β -D-C-oligosaccharide products into their corresponding epoxides and subsequent deprotection under standard conditions have afforded a panel of epoxyalkyl β -C-oligosaccharides for evaluation as inhibitors of retaining β-glycan hydrolases.

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Biswas, Ansuman, and Mukund Thattai. "Promiscuity and specificity of eukaryotic glycosyltransferases." Biochemical Society Transactions 48, no. 3 (June 15, 2020): 891–900. http://dx.doi.org/10.1042/bst20190651.

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Glycosyltransferases are a large family of enzymes responsible for covalently linking sugar monosaccharides to a variety of organic substrates. These enzymes drive the synthesis of complex oligosaccharides known as glycans, which play key roles in inter-cellular interactions across all the kingdoms of life; they also catalyze sugar attachment during the synthesis of small-molecule metabolites such as plant flavonoids. A given glycosyltransferase enzyme is typically responsible for attaching a specific donor monosaccharide, via a specific glycosidic linkage, to a specific moiety on the acceptor substrate. However these enzymes are often promiscuous, able catalyze linkages between a variety of donors and acceptors. In this review we discuss distinct classes of glycosyltransferase promiscuity, each illustrated by enzymatic examples from small-molecule or glycan synthesis. We highlight the physical causes of promiscuity, and its biochemical consequences. Structural studies of glycosyltransferases involved in glycan synthesis show that they make specific contacts with ‘recognition motifs’ that are much smaller than the full oligosaccharide substrate. There is a wide range in the sizes of glycosyltransferase recognition motifs: highly promiscuous enzymes recognize monosaccharide or disaccharide motifs across multiple oligosaccharides, while highly specific enzymes recognize large, complex motifs found on few oligosaccharides. In eukaryotes, the localization of glycosyltransferases within compartments of the Golgi apparatus may play a role in mitigating the glycan variability caused by enzyme promiscuity.

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Wong, Dominic W. S. "The Use of Plant Fibers for Oligosaccharide Production with Libraries Constructed by Combinatorial Enzyme Technology." Current Biotechnology 10, no. 3 (September 2021): 168–77. http://dx.doi.org/10.2174/2211550111666211216110556.

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: Combinatorial chemistry involves the chemical or biological synthesis of libraries of the diverse structural population of a template molecule and the screening for the variants expressing desirable target properties. The approach has been a focus of research activity in modern drug discovery and biotechnology for accelerating the discovery and development of novel therapeutic and bioactive compounds. This review describes the application of combinatorial chemistry in enzyme technology as a novel technique and invention developed in our laboratory to construct oligosaccharide libraries in the conversion of plant fibers. The theory, mechanism, development, and application of this combinatorial enzyme approach are presented for the first time. The potential food and non-food uses of oligosaccharides are described. Citrus pectin and wheat insoluble fiber have been used as substrates for combinatorial enzyme reactions. Generation of libraries of structural variants of pectic oligosaccharides (oligoGalA) and feruloyl oligosaccharides (FOS) demonstrates the feasibility and usefulness of the technique in the transformation of plant biomass to value- added products.

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Ogata, Makoto. "Chemoenzymatic Synthesis and Function of Chitin Derivatives." Current Pharmaceutical Design 26, no. 29 (September 4, 2020): 3522–29. http://dx.doi.org/10.2174/1381612826666200515132623.

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Chitin, abundant biomass found in crab shells and other marine life, has wide applications in the production of food, pharmaceuticals, and cosmetics. Our recent studies have focused on the development of new functional materials by derivatizing chitin oligosaccharides and monosaccharides. For example, we have prepared various derivatives by chemoenzymatic synthesis using N-acetylglucosamine (GlcNAc) or chitin oligosaccharide prepared from chitin as starting materials. First, we have achieved the total synthesis of two secondary metabolites (furanodictine A and B) with neuronal differentiation-inducing activity on PC12 cells by using a simple heatinduced structural transformation of GlcNAc and esterification reaction. Second, we synthesized both a novel inhibitor that has facilitated a re-examination of the reaction mechanism of hen egg-white lysozyme, and a new substrate for assaying lysozyme activity by using chitin oligosaccharides as raw materials. Thus, the development of new materials by simple derivatization of chitin mono- or oligo-saccharides is paving the way for effective use of chitin.

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32

Adegbite, Ayobami, and Pumtiwitt C. McCarthy. "Recent and Future Advances in the Chemoenzymatic Synthesis of Homogeneous Glycans for Bacterial Glycoconjugate Vaccine Development." Vaccines 9, no. 9 (September 14, 2021): 1021. http://dx.doi.org/10.3390/vaccines9091021.

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Vaccines are important in preventing disease outbreaks and controlling the spread of disease in a population. A variety of vaccines exist, including subunit, recombinant, and conjugate vaccines. Glycoconjugate vaccines have been an important tool to fight against diseases caused by a number of bacteria. Glycoconjugate vaccines are often heterogeneous. Vaccines of the future are becoming more rationally designed to have a defined oligosaccharide chain length and position of conjugation. Homogenous vaccines could play an important role in assessing the relationship between vaccine structure and immune response. This review focuses on recent advances in the chemoenzymatic production of defined bacterial oligosaccharides for vaccine development with a focus on Neisseria meningitidis and selected WHO-prioritized antibacterial resistant-pathogens. We also provide some perspective on future advances in the chemoenzymatic synthesis of well-defined oligosaccharides.

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33

Coppa, Giovanni V., Orazio Gabrielli, Paolo Pierani, Carlo Catassi, Antonio Carlucci, and Pier L. Giorgi. "Changes in Carbohydrate Composition in Human Milk Over 4 Months of Lactation." Pediatrics 91, no. 3 (March 1, 1993): 637–41. http://dx.doi.org/10.1542/peds.91.3.637.

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This study aimed to examine the carbohydrate content (monosaccharides, lactose, and oligosaccharides) of human milk over 4 months of lactation to determine whether any changes occurred over time. Milk samples from 46 mothers, who delivered at term, were collected at 4th, 10th, 30th, 60th, 90th, and 120th days after delivery. Carbohydrates were measured by high-pressure liquid chromatography. Mean lactose concentration (±SD) increased from 56 ± 6.06 g/L on day 4 to 68.9 ± 8.16 g/L on day 120. Oligosaccharide level decreased from 20.9 ± 4.81 g/L to 12.9 ± 3.30 g/L, respectively. Monosaccharides represented only 1.2% of total carbohydrates. The changes in carbohydrate composition found indicate that carbohydrate synthesis by the mammary gland is a dynamic process. The physiological and biological relevance of human milk oligosaccharides is also discussed.

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Kabakoff, B., and W. J. Lennarz. "Inhibition of glycoprotein processing blocks assembly of spicules during development of the sea urchin embryo." Journal of Cell Biology 111, no. 2 (August 1, 1990): 391–400. http://dx.doi.org/10.1083/jcb.111.2.391.

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Previous studies have implicated an 130-kD glycoprotein containing complex, N-linked oligosaccharide chain(s) in the process of spicule formation in sea urchin embryos. To ascertain whether the processing of high mannose oligosaccharides to complex oligosaccharides is necessary for spiculogenesis, intact embryos and cultures of spicule-forming primary mesenchyme cells were treated with glycoprotein processing inhibitors. In both the embryonic and cell culture systems 1-deoxymannojirimycin (1-MMN) and, to a lesser extent, 1-deoxynojirimycin (1-DNJ) inhibited spicule formation. These inhibitors did not affect gastrulation in whole embryos or filopodial network formation in cell cultures. Swainsonine (SWSN) and castanospermine (CSTP) had no effect in either system. Further analysis revealed the following: (a) 1-MMN entered the embryos and blocked glycoprotein processing in the 24-h period before spicule formation as assessed by a twofold increase in endoglycosidase H sensitivity among newly synthesized glycoproteins upon addition of 1-MMN; (b) 1-MMN did not affect general protein synthesis until after its effects on spicule formation were observed; (c) Immunoblot analysis with an antibody directed towards the polypeptide chain of the 130-kD protein (mAb A3) demonstrated that 1-MMN did not affect the level of the polypeptide that is known to be synthesized just before spicule formation; (d) 1-MMN and 1-DNJ almost completely abolished (greater than 95%) the appearance of mAb 1223 reactive complex oligosaccharide moiety associated with the 130-kD glycoprotein; CSTP and SWSN had much less of an effect on expression of this epitope. These results indicate that the conversion of high mannose oligosaccharides to complex oligosaccharides is required for spiculogenesis in sea urchin embryos and they suggest that the 130-kD protein is one of these essential complex glycoproteins.

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Monchois, Vincent, Michel Vignon, and Roy R. B. Russell. "Mutagenesis of Asp-569 of Glucosyltransferase I Glucansucrase Modulates Glucan and Oligosaccharide Synthesis." Applied and Environmental Microbiology 66, no. 5 (May 1, 2000): 1923–27. http://dx.doi.org/10.1128/aem.66.5.1923-1927.2000.

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ABSTRACT Glucansucrases of oral streptococci and Leuconostoc mesenteroides are enzymes of medical and biotechnological interest that synthesize α-glucans. They can also synthesize oligosaccharides in the presence of a sugar acceptor. Previous reports have identified an amino acid residue that may affect the structure of the glucan product; therefore, random mutagenesis of the corresponding Asp-569 of Streptococcus downei glucosyltransferase I (GTF-I) was used to further understanding of its involvement in the catalytic mechanism and to evaluate how different amino acids can modulate glucan and oligosaccharide synthesis. GTF-I variants were obtained where Asp-569 was replaced by each of the different possible classes of amino acids. These were expressed in Escherichia coli and purified by means of a His6 tag. The results showed that the amino acid in position 569 influences the structure of the glucan and the size of the oligosaccharides produced by GTF-I. The results suggest that the amino acid occupying this position is more likely to interact with the acceptor molecules (oligosaccharides or elongating glucan chain) than to be directly involved in glucosyl transfer from sucrose. Engineering of the equivalent position in glucansucrases thus appears to be a good target to expand the range of oligosaccharides synthesized.

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Ying, Li, Han Shuqin, Toshiyuki Uryu, and Takashi Yoshida. "Synthesis of New Spherical Polylysine Oligosaccharide Dendrimers with C6 Methylene Spacer." Sen'i Gakkaishi 71, no. 1 (2015): 10–17. http://dx.doi.org/10.2115/fiber.71.10.

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37

Chan, V. T., and G. Wolf. "The role of vitamin A in the glycosylation reactions of glycoprotein synthesis in an ‘in vitro’ system." Biochemical Journal 247, no. 1 (October 1, 1987): 53–62. http://dx.doi.org/10.1042/bj2470053.

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Microsomal membrane preparations from rat livers, when incubated with labelled sugar-nucleotides, were shown to synthesize labelled oligosaccharide-lipids in the presence of excess exogenous dolichyl phosphate. Under the incubation conditions defined in the present study, dolichyl pyrophosphoryl(DolPP)GlcNAc2-Man5, DolPPGlcNAc2Man9 and DolPPGlcNAc2Man9Glc3 were the principal oligosaccharide-lipids formed by both control and vitamin A-deficient membranes. However, deficient membranes synthesized 3.2 +/- 0.8 times as much oligosaccharide-lipids and 2.6 +/- 0.7 times as much dolichyl phosphate mannose (DolPMan) and dolichyl phosphate glucose (DolPGlc) as the controls. The transfer of the oligosaccharide chain from the dolichol carrier to the endogenous protein acceptors in vitamin A-deficient microsomes (microsomal fractions) was only 57.5 +/- 9.5% of that of controls. After endo-beta-N-acetylglucosaminidase treatment, only one oligosaccharide species was isolated from both control and vitamin A-deficient microsomal glycoproteins, and was characterized as GlcNAcMan9Glc3. We conclude that the decreased incorporation of labelled mannose and glucose from sugar-nucleotides into the glycoproteins must be due to decreased transfer of GlcNAc2Man9Glc3 from the dolichol carrier to the protein acceptors. This conclusion was further substantiated by the finding that control membranes transferred 4-6 times as much labelled oligosaccharides from exogenously added dolichol-linked substrate (DolPPGlcNAc2Man9Glc3) to endogenous microsomal protein acceptors as compared with the vitamin A-deficient membranes. Attempts to reverse this defect by addition of retinol or retinyl phosphate (a source of retinyl phosphate mannose) to the incubations were unsuccessful.

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Li, Feng Hong, Wen Jing Zhang, San Xi Li, Yan Ming Chen, and Xin Rui Zhang. "Synthesis and Characterization of an Amphiphilic Nanoparticles Based on Chitosan Oligosaccharide-Grafted-Polycaprolactone." Applied Mechanics and Materials 513-517 (February 2014): 86–90. http://dx.doi.org/10.4028/www.scientific.net/amm.513-517.86.

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The amphiphilic chitosan oligosaccharides graft copolymer (PHCSO-g-PCL) was synthesized via ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) through an amino group protection route using phthaloyl chitosan oligosaccharide (PHCSO) as intermediate. The graft reaction was carried out in Pyridine at 120 °C with a chitosan oligosaccharide (CSO) initiator and a tin 2-ethylhexanoate (Sn (Oct)2) catalyst. The amphiphilic PHCSO-g-PCL nanoparticles were prepared through the self-assembled in DMF organic solvents. PHCSO-PCL copolymer was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The physicochemical properties of the hydrophobized PHCSO-g-PCL nanoparticles were investigated by using dynamic light scattering (DLS). The results of DLS showed that the hydrodynamic diameters and particle size distribution with various concentrations of PHCSO-g-PCL nanoparticles were from 69.82 nm to 195.9 nm with a narrow polydispersity factor of 0.212 to 0.172.

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39

Fabre, Emeline, Sophie Bozonnet, Audrey Arcache, René-Marc Willemot, Michel Vignon, Pierre Monsan, and Magali Remaud-Simeon. "Role of the Two Catalytic Domains of DSR-E Dextransucrase and Their Involvement in the Formation of Highly α-1,2 Branched Dextran." Journal of Bacteriology 187, no. 1 (January 1, 2005): 296–303. http://dx.doi.org/10.1128/jb.187.1.296-303.2005.

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ABSTRACT The dsrE gene from Leuconostoc mesenteroides NRRL B-1299 was shown to encode a very large protein with two potentially active catalytic domains (CD1 and CD2) separated by a glucan binding domain (GBD). From sequence analysis, DSR-E was classified in glucoside hydrolase family 70, where it is the only enzyme to have two catalytic domains. The recombinant protein DSR-E synthesizes both α-1,6 and α-1,2 glucosidic linkages in transglucosylation reactions using sucrose as the donor and maltose as the acceptor. To investigate the specific roles of CD1 and CD2 in the catalytic mechanism, truncated forms of dsrE were cloned and expressed in Escherichia coli. Gene products were then small-scale purified to isolate the various corresponding enzymes. Dextran and oligosaccharide syntheses were performed. Structural characterization by 13C nuclear magnetic resonance and/or high-performance liquid chromatography showed that enzymes devoid of CD2 synthesized products containing only α-1,6 linkages. On the other hand, enzymes devoid of CD1 modified α-1,6 linear oligosaccharides and dextran acceptors through the formation of α-1,2 linkages. Therefore, each domain is highly regiospecific, CD1 being specific for the synthesis of α-1,6 glucosidic bonds and CD2 only catalyzing the formation of α-1,2 linkages. This finding permitted us to elucidate the mechanism of α-1,2 branching formation and to engineer a novel transglucosidase specific for the formation of α-1,2 linkages. This enzyme will be very useful to control the rate of α-1,2 linkage synthesis in dextran or oligosaccharide production.

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Hahm, Heung Sik, Mark K. Schlegel, Mattan Hurevich, Steffen Eller, Frank Schuhmacher, Johanna Hofmann, Kevin Pagel, and Peter H. Seeberger. "Automated glycan assembly using the Glyconeer 2.1 synthesizer." Proceedings of the National Academy of Sciences 114, no. 17 (April 10, 2017): E3385—E3389. http://dx.doi.org/10.1073/pnas.1700141114.

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Reliable and rapid access to defined biopolymers by automated DNA and peptide synthesis has fundamentally altered biological research and medical practice. Similarly, the procurement of defined glycans is key to establishing structure–activity relationships and thereby progress in the glycosciences. Here, we describe the rapid assembly of oligosaccharides using the commercially available Glyconeer 2.1 automated glycan synthesizer, monosaccharide building blocks, and a linker-functionalized polystyrene solid support. Purification and quality-control protocols for the oligosaccharide products have been standardized. Synthetic glycans prepared in this way are useful reagents as the basis for glycan arrays, diagnostics, and carbohydrate-based vaccines.

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Vervecken, Wouter, Vladimir Kaigorodov, Nico Callewaert, Steven Geysens, Kristof De Vusser, and Roland Contreras. "In Vivo Synthesis of Mammalian-Like, Hybrid-Type N-Glycans in Pichia pastoris." Applied and Environmental Microbiology 70, no. 5 (May 2004): 2639–46. http://dx.doi.org/10.1128/aem.70.5.2639-2646.2004.

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ABSTRACT The Pichia pastoris N-glycosylation pathway is only partially homologous to the pathway in human cells. In the Golgi apparatus, human cells synthesize complex oligosaccharides, whereas Pichia cells form mannose structures that can contain up to 40 mannose residues. This hypermannosylation of secreted glycoproteins hampers the downstream processing of heterologously expressed glycoproteins and leads to the production of protein-based therapeutic agents that are rapidly cleared from the blood because of the presence of terminal mannose residues. Here, we describe engineering of the P. pastoris N-glycosylation pathway to produce nonhyperglycosylated hybrid glycans. This was accomplished by inactivation of OCH1 and overexpression of an α-1,2-mannosidase retained in the endoplasmic reticulum and N-acetylglucosaminyltransferase I and β-1,4-galactosyltransferase retained in the Golgi apparatus. The engineered strain synthesized a nonsialylated hybrid-type N-linked oligosaccharide structure on its glycoproteins. The procedures which we developed allow glycan engineering of any P. pastoris expression strain and can yield up to 90% homogeneous protein-linked oligosaccharides.

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Weishaupt, Markus W., Stefan Matthies, Mattan Hurevich, Claney L. Pereira, Heung Sik Hahm, and Peter H. Seeberger. "Automated glycan assembly of aS. pneumoniaeserotype 3 CPS antigen." Beilstein Journal of Organic Chemistry 12 (July 12, 2016): 1440–46. http://dx.doi.org/10.3762/bjoc.12.139.

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Vaccines againstS. pneumoniae, one of the most prevalent bacterial infections causing severe disease, rely on isolated capsular polysaccharide (CPS) that are conjugated to proteins. Such isolates contain a heterogeneous oligosaccharide mixture of different chain lengths and frame shifts. Access to defined syntheticS. pneumoniaeCPS structures is desirable. Known syntheses ofS. pneumoniaeserotype 3 CPS rely on a time-consuming and low-yielding late-stage oxidation step, or use disaccharide building blocks which limits variability. Herein, we report the first iterative automated glycan assembly (AGA) of a conjugation-readyS. pneumoniaeserotype 3 CPS trisaccharide. This oligosaccharide was assembled using a novel glucuronic acid building block to circumvent the need for a late-stage oxidation. The introduction of a washing step with the activator prior to each glycosylation cycle greatly increased the yields by neutralizing any residual base from deprotection steps in the synthetic cycle. This process improvement is applicable to AGA of many other oligosaccharides.

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Skelton, Timothy P., Chunxun Zeng, Aaron Nocks, and Ivan Stamenkovic. "Glycosylation Provides Both Stimulatory and Inhibitory Effects on Cell Surface and Soluble CD44 Binding to Hyaluronan." Journal of Cell Biology 140, no. 2 (January 26, 1998): 431–46. http://dx.doi.org/10.1083/jcb.140.2.431.

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Glycosylation has been implicated in the regulation of CD44-mediated cell binding of hyaluronan (HA). However, neither the relative contribution of N- and O-linked glycans nor the oligosaccharide structures that alter CD44 affinity for HA have been elucidated. To determine the effect of selective alteration of CD44 oligosaccharide composition on the affinity of CD44 for HA, we developed a novel strategy based on the use of affinity capillary electrophoresis (ACE). Soluble recombinant CD44–immunoglobulin fusion proteins were overproduced in the mutant CHO cell line ldl-D, which has reversible defects in both N- and O-linked oligosaccharide synthesis. Using this cell line, a panel of recombinant glycosidases, and metabolic glycosidase inhibitors, CD44 glycoforms with defined oligosaccharide structures were generated and tested for HA affinity by ACE. Because ldl-D cells express endogenous cell surface CD44, the effect of any given glycosylation change on the ability of cell surface and soluble CD44 to bind HA could be compared. Four distinct oligosaccharide structures were found to effect CD44-mediated HA binding: (a) the terminal α2,3-linked sialic acid on N-linked oligosaccharides inhibited binding; (b) the first N-linked N-acetylglucosamine residue enhanced binding; (c) O-linked glycans on N-deglycosylated CD44 enhanced binding; and (d) N-acetylgalactosamine incorporation into non–N-linked glycans augmented HA binding by cell surface CD44. The first three structures induced up to a 30-fold alteration in the intrinsic CD44 affinity for HA (Kd = 5 to >150 μM). The fourth augmented CD44-mediated cellular HA avidity without changing the intrinsic HA affinity of soluble CD44.

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Léonard, Estelle, and Antoine Fayeulle. "Azo-Dyes-Grafted Oligosaccharides—From Synthesis to Applications." Molecules 26, no. 11 (May 21, 2021): 3063. http://dx.doi.org/10.3390/molecules26113063.

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Azobenzenes are photochromic molecules that possess a large range of applications. Their syntheses are usually simple and fast, and their purifications can be easy to perform. Oligosaccharide is also a wide family of biopolymer constituted of linear chain of saccharides. It can be extracted from biomass, as for cellulose, being the principal constituent of plant cell wall, or it can be enzymatically produced as for cyclodextrins, having properties not far from cellulose. Combining these two materials families can afford interesting applications such as controlled drug-release systems, photochromic liquid crystals, photoresponsive films or even fluorescent indicators. This review will compile the different syntheses of azo-dyes-grafted oligosaccharides, and will show their various applications.

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Gundlach, M. W., and H. E. Conrad. "Glycosyl transferases in chondroitin sulphate biosynthesis. Effect of acceptor structure on activity." Biochemical Journal 226, no. 3 (March 15, 1985): 705–14. http://dx.doi.org/10.1042/bj2260705.

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The D-glucuronosyl (GlcA)- and N-acetyl-D-galactosaminyl (GalNAc)-transferases involved in chondroitin sulphate biosynthesis were studied in a microsomal preparation from chick-embryo chondrocytes. Transfer of GlcA and GalNAc from their UDP derivatives to 3H-labelled oligosaccharides prepared from chondroitin sulphate and hyaluronic acid was assayed by h.p.l.c. of the reaction mixture. Conditions required for maximal activities of the two enzymes were remarkably similar. Activities were stimulated 3.5-6-fold by neutral detergents. Both enzymes were completely inhibited by EDTA and maximally stimulated by MnCl2 or CoCl2. MgCl2 neither stimulated nor inhibited. The GlcA transferase showed a sharp pH optimum between pH5 and 6, whereas the GalNAc transferase gave a broad optimum from pH 5 to 8. At pH 7 under optimal conditions, the GalNAc transferase gave a velocity that was twice that of the GlcA transferase. Oligosaccharides prepared from chondroitin 4-sulphate and hyaluronic acid were almost inactive as acceptors for both enzymes, whereas oligosaccharides from chondroitin 6-sulphate and chondroitin gave similar rates that were 70-80-fold higher than those observed with the endogenous acceptors. Oligosaccharide acceptors with degrees of polymerization of 6 or higher gave similar Km and Vmax. values, but the smaller oligosaccharides were less effective acceptors. These results are discussed in terms of the implications for regulation of the overall rates of the chain-elongation fractions in chondroitin sulphate synthesis in vivo.

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Fairbanks, Antony J. "Endohexosaminidase-catalyzed synthesis of glycopeptides and proteins." Pure and Applied Chemistry 85, no. 9 (September 1, 2013): 1847–63. http://dx.doi.org/10.1351/pac-con-12-09-10.

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The synthetic application of endohexosaminidase enzymes (e.g., Endo A, Endo M, Endo D) promises to allow ready access to a wide variety of defined homogeneous glycoproteins and glycopeptides. The use ofN-glycan oligosaccharides that are activated at the reducing terminus as oxazolines allows their high-yielding attachment to almost any amino acid, peptide, or protein that contains a GlcNAc residue as an acceptor. A wide variety of oxazoline donors are readily available, either by total synthesis or by isolation of the corresponding oligosaccharide from natural sources and then conversion to the oxazoline in water. The synthetic potential of the enzymes is particularly augmented by the production of mutant glycosynthases, the use of which allows the synthesis of a wide variety of glycopeptides and glycoproteins bearing defined homogeneousN-glycan structures.

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Tsvetkov, Yury E., Marina L. Gening, Ekaterina A. Kurbatova, Nelly K. Akhmatova, and Nikolay E. Nifantiev. "Oligosaccharide ligand tuning in design of third generation carbohydrate pneumococcal vaccines." Pure and Applied Chemistry 89, no. 10 (September 26, 2017): 1403–11. http://dx.doi.org/10.1515/pac-2016-1123.

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AbstractStreptococcus pneumoniae can cause many types of dangerous infectious diseases such as otitis media, pneumonia, meningitis and others that are more common in the very young and very old age. Available to date commercial vaccines based on capsular polysaccharides of S. pneumoniae of clinically important strains (first generation carbohydrate vaccines) and conjugated vaccines based on these polysaccharides (second generation carbohydrate vaccines) have certain limitations in protective efficiency. However, the efficiency of vaccines can be increased by the use of third generation vaccines based on synthetic oligosaccharide ligands representing in their structures the protective epitopes of capsular polysaccharides. The proper choice of an optimal oligosaccharide ligand is the most important step in the design of third generation carbohydrate vaccines. Herein we overview our works on the synthesis of three oligosaccharides corresponding to one, “one and a half” and two repeating units of S. pneumoniae type 14 capsular polysaccharide, immunogenic conjugates thereof and comparative immunological study of their conjugates with bovine serum albumin, which was used as a model protein carrier. The ability of obtained products to raise antibodies specific to capsular polysaccharide and homologous oligosaccharides, the induction of phagocytosis by immune antisera and active protection of immunized animals from S. pneumoniae type 14 infection were evaluated. On the basis of the results obtained tetrasaccharide comprising the repeating unit of S. pneumoniae type 14 capsular polysaccharide is an optimal carbohydrate ligand to be used as a part of the third generation carbohydrate pneumococcal vaccine.

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Chen, Xiaodi, Li Xu, Lan Jin, Bin Sun, Guofeng Gu, Lili Lu, and Min Xiao. "Efficient and Regioselective Synthesis of β-GalNAc/GlcNAc-Lactose by a Bifunctional Transglycosylating β-N-Acetylhexosaminidase from Bifidobacterium bifidum." Applied and Environmental Microbiology 82, no. 18 (July 15, 2016): 5642–52. http://dx.doi.org/10.1128/aem.01325-16.

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ABSTRACTβ-N-Acetylhexosaminidases have attracted interest particularly for oligosaccharide synthesis, but their use remains limited by the rarity of enzyme sources , low efficiency, and relaxed regioselectivity of transglycosylation. In this work, genes of 13 β-N-acetylhexosaminidases, including 5 fromBacteroides fragilisATCC 25285, 5 fromClostridium perfringensATCC 13124, and 3 fromBifidobacterium bifidumJCM 1254, were cloned and heterogeneously expressed inEscherichia coli. The resulting recombinant enzymes were purified and screened for transglycosylation activity. A β-N-acetylhexosaminidase named BbhI, which belongs to glycoside hydrolase family 20 and was obtained fromB. bifidumJCM 1254, possesses the bifunctional property of efficiently transferring both GalNAc and GlcNAc residues through β1-3 linkage to the Gal residue of lactose. The effects of initial substrate concentration, pH, temperature, and reaction time on transglycosylation activities of BbhI were studied in detail. With the use of 10 mMpNP-β-GalNAc or 20 mMpNP-β-GlcNAc as the donor and 400 mM lactose as the acceptor in phosphate buffer (pH 5.8), BbhI synthesized GalNAcβ1-3Galβ1-4Glc and GlcNAcβ1-3Galβ1-4Glc at maximal yields of 55.4% at 45°C and 4 h and 44.9% at 55°C and 1.5 h, respectively. The model docking of BbhI with lactose showed the possible molecular basis of strict regioselectivity of β1-3 linkage in β-N-acetylhexosaminyl lactose synthesis.IMPORTANCEOligosaccharides play a crucial role in many biological events and therefore are promising potential therapeutic agents. However, their use is limited because large-scale production of oligosaccharides is difficult. The chemical synthesis requires multiple protecting group manipulations to control the regio- and stereoselectivity of glycosidic bonds. In comparison, enzymatic synthesis can produce oligosaccharides in one step by using glycosyltransferases and glycosidases. Given the lower price of their glycosyl donor and their broader acceptor specificity, glycosidases are more advantageous than glycosyltransferases for large-scale synthesis. β-N-Acetylhexosaminidases have attracted interest particularly for β-N-acetylhexosaminyl oligosaccharide synthesis, but their application is affected by having few enzyme sources, low efficiency, and relaxed regioselectivity of transglycosylation. In this work, we describe a microbial β-N-acetylhexosaminidase that exhibited strong transglycosylation activity and strict regioselectivity for β-N-acetylhexosaminyl lactose synthesis and thus provides a powerful synthetic tool to obtain biologically important GalNAcβ1-3Lac and GlcNAcβ1-3Lac.

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Grinevich, A. S., I. V. Chinareva, O. S. Burova, and P. K. Ivanov. "FLUORESCENT MODIFICATION OF THE MONOCLONAL ANTIBODIES OLIGOSACCHARIDES BY FLUORESCEIN-5-THIOSEMICARBAZIDE." Russian Journal of Biotherapy 19, no. 2 (June 18, 2020): 39–46. http://dx.doi.org/10.17650/1726-9784-2019-19-2-39-46.

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Introduction Monoclonal antibodies (Mabs) are a good tool for diagnosing human pathologies. They are used as conjugates with fluorescent and other dyes. The classical approach of creating such conjugates is reduced to chemical reactions using the protein base of the Mab. At the same time, for a number of Mabs, conjugate production is accompanied by embedding the label into the antigen binding site, which leads to a decrease or complete loss of the specific activity of the conjugate. To get out of this situation, the synthesis of fluorescent conjugates by methods of carbohydrate chemistry through spatially distant from the active center oligosaccharides of antibodies is proposed. Objective To obtain high activity ICO series Mab conjugates based on the reaction of covalent inclusion of the fluorescent label in the oligosaccharide sequence of the Mab. Materials and methods We used Mab series ICO of high purity. Oligosaccharides Mabs oxidized to aldehyde groups, were subjected to interaction with fluoriscine-5-thiosemicarboside, followed by the reduction of hydrazone derivative borgidrides. The resulting covalent conjugate was investigated in a flow cytometry. Results The synthesis of a fluorescent conjugate using monoclonal antibodies oligosaccharides was worked out. Modified monoclonal antibodies retain specific binding to target cells inherent in the native antibody. The resulting conjugates remained active for a long time during storage. Conclusion An alternative method for conjugation of immunofluorescent, allowing to obtain conjugates of high activity, has been developed.

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Di Fabio, Giovanni, Antonio Randazzo, Jennifer D'Onofrio, Cristina Ausín, Enrique Pedroso, Anna Grandas, Lorenzo De Napoli, and Daniela Montesarchio. "Cyclic Phosphate-Linked Oligosaccharides: Synthesis and Conformational Behavior of Novel Cyclic Oligosaccharide Analogues." Journal of Organic Chemistry 71, no. 9 (April 2006): 3395–408. http://dx.doi.org/10.1021/jo0600757.

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Journal articles on the topic 'Oligosaccharide Synthesi'

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