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1.
Phytochemistry ; 175: 112313, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32353551

RESUMO

The structures and cytotoxic activities of water-soluble polysaccharides were investigated to search for biologically active polysaccharides from the fruit bodies of quinine conks (Fomitopsis officinalis). The decoctions of this medical fungus are actively used in folk medicine in many countries and traditional Chinese medicine. From the fungal extract we prepared, only branched ß-glucan had cytotoxic activity among all the water-soluble polysaccharides. This glucan is characterized by a regular structure. Its backbone is formed by 1,3-linked ß-D-Glcp residues, of which every third residue is substituted at O-6 by a single ß-D-Glcp residue. It has a triple helix conformation according to the data obtained from a colorimetric assay with Congo red dye and is characterized by a high-weight average molar mass (Mw > 800 kDa). ß-Glucan possessed cytotoxic activity against HeLa cells (IC50 = 318 ±â€¯47 µg/mL) and induced the formation of apoptotic bodies around most cancer cells at a concentration of 200 µg/mL. It should be noted that extraction with boiling water, which is usually used to obtain extracts and decoctions, is unable to isolate active ß-glucan. Active ß-glucan can be obtained in an individual state by cold alkali extraction after dehydration of the fruit bodies and removal of the components extractable by boiling water.


Assuntos
Quinina , Água , Sequência de Carboidratos , Frutas , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Polissacarídeos
2.
PLoS One ; 15(2): e0228507, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32045434

RESUMO

Human chorionic gonadotropin (hCG) is a glycoprotein hormone that is essential for the maintenance of pregnancy. Glycosylation of hCG is known to be essential for its biological activity. "Hyperglycosylated" variants secreted during early pregnancy have been proposed to be involved in initial implantation of the embryo and as a potential diagnostic marker for gestational diseases. However, what constitutes "hyperglycosylation" is not yet fully understood. In this study, we perform comparative N-glycomic analysis of hCG expressed in the same individuals during early and late pregnancy to help provide new insights into hCG function, reveal new targets for diagnostics and clarify the identity of hyperglycosylated hCG. hCG was isolated in urine collected from women at 7 weeks and 20 weeks' gestation. hCG was also isolated in urine from women diagnosed with gestational trophoblastic disease (GTD). We used glycomics methodologies including matrix assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass spectrometry (MS) and MS/MS methods to characterise the N-glycans associated with hCG purified from the individual samples. The structures identified on the early pregnancy (EP-hCG) and late pregnancy (LP-hCG) samples corresponded to mono-, bi-, tri-, and tetra-antennary N-glycans. A novel finding was the presence of substantial amounts of bisected type N-glycans in pregnancy hCG samples, which were present at much lower levels in GTD samples. A second novel observation was the presence of abundant LewisX antigens on the bisected N-glycans. GTD-hCG had fewer glycoforms which constituted a subset of those found in normal pregnancy. When compared to EP-hCG, GTD-hCG samples had decreased signals for tri- and tetra-antennary N-glycans. In terms of terminal epitopes, GTD-hCG had increased signals for sialylated structures, while LewisX antigens were of very minor abundance. hCG carries the same N-glycans throughout pregnancy but in different proportions. The N-glycan repertoire is more diverse than previously reported. Bisected and LewisX structures are potential targets for diagnostics. hCG isolated from pregnancy urine inhibits NK cell cytotoxicity in vitro at nanomolar levels and bisected type glycans have previously been implicated in the suppression of NK cell cytotoxicity, suggesting that hCG-related bisected type N-glycans may directly suppress NK cell cytotoxicity.


Assuntos
Gonadotropina Coriônica Humana Subunidade beta/metabolismo , Polissacarídeos/metabolismo , Processamento de Proteína Pós-Traducional , Sequência de Carboidratos , Gonadotropina Coriônica Humana Subunidade beta/sangue , Gonadotropina Coriônica Humana Subunidade beta/urina , Feminino , Idade Gestacional , Doença Trofoblástica Gestacional/sangue , Doença Trofoblástica Gestacional/metabolismo , Doença Trofoblástica Gestacional/urina , Glicômica/métodos , Glicosilação , Humanos , Gravidez , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem
3.
Nat Commun ; 11(1): 973, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-32080177

RESUMO

Core-fucosylation is an essential biological modification by which a fucose is transferred from GDP-ß-L-fucose to the innermost N-acetylglucosamine residue of N-linked glycans. A single human enzyme α1,6-fucosyltransferase (FUT8) is the only enzyme responsible for this modification via the addition of an α-1,6-linked fucose to N-glycans. To date, the details of substrate recognition and catalysis by FUT8 remain unknown. Here, we report the crystal structure of FUT8 complexed with GDP and a biantennary complex N-glycan (G0), which provides insight into both substrate recognition and catalysis. FUT8 follows an SN2 mechanism and deploys a series of loops and an α-helix which all contribute in forming the binding site. An exosite, formed by one of these loops and an SH3 domain, is responsible for the recognition of branched sugars, making contacts specifically to the α1,3 arm GlcNAc, a feature required for catalysis. This information serves as a framework for inhibitor design, and helps to assess its potential as a therapeutic target.


Assuntos
Fucosiltransferases/química , Fucosiltransferases/metabolismo , Biocatálise , Sequência de Carboidratos , Domínio Catalítico , Cristalografia por Raios X , Glicosilação , Guanosina Difosfato/metabolismo , Humanos , Análise em Microsséries , Modelos Moleculares , Polissacarídeos/química , Polissacarídeos/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Domínios de Homologia de src
4.
Mol Immunol ; 120: 74-82, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32087569

RESUMO

To understand the role of human natural IgM known as antibodies against the carbohydrate epitope Tn, the antibodies were isolated using GalNAcα-Sepharose affinity chromatography, and their specificity was profiled using microarrays (a glycan array printed with oligosaccharides and bacterial polysaccharides, as well as a glycopeptide array), flow cytometry, and inhibition ELISA. The antibodies bound a restricted number of GalNAcα-terminated oligosaccharides better than the parent monosaccharide, e.g., 6-O-Su-GalNAcα and GalNAcα1-3Galß1-3(4)GlcNAcß. The binding with several bacterial polysaccharides that have no structural resemblance to the affinity ligand GalNAcα was quite unexpected. Given that GalNAcα is considered the key fragment of the Tn antigen, it is surprising that these antibodies bind weakly GalNAcα-OSer and do not bind a wide variety of GalNAcα-OSer/Thr-containing mucin glycopeptides. At the same time, we have observed specific binding to cells having Tn-positive glycoproteins containing similar glycopeptide motifs in a conformationally rigid macromolecule. Thus, specific recognition of the Tn antigen apparently requires that the naturally occurring "anti-Tn" IgM recognize a complex epitope comprising the GalNAcα as an essential component and a fairly long amino acid sequence where the amino acids adjacent to GalNAcα do not contact the antibody paratope; i.e., the antibodies recognize a spatial epitope or a molecular pattern rather than a classical continuous sequence. In addition, we have not found any increase in the binding of natural antibodies when GalNAcα residues were clustered. These results may help in further development of anticancer vaccines based on synthetic Tn constructs.


Assuntos
Antígenos Glicosídicos Associados a Tumores/imunologia , Sequência de Aminoácidos , Afinidade de Anticorpos , Especificidade de Anticorpos , Reações Antígeno-Anticorpo/imunologia , Antígenos Glicosídicos Associados a Tumores/química , Sequência de Carboidratos , Epitopos/química , Epitopos/imunologia , Epitopos/isolamento & purificação , Humanos , Imunidade Inata , Imunoglobulina M/imunologia , Imunoglobulina M/isolamento & purificação , Células Jurkat , Neoplasias/imunologia
5.
World J Microbiol Biotechnol ; 36(1): 14, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31897771

RESUMO

Glycogen is conventionally considered as a transient energy reserve that can be rapidly synthesized for glucose accumulation and mobilized for ATP production. However, this conception is not completely applicable to prokaryotes due to glycogen structural heterogeneity. A number of studies noticed that glycogen with small average chain length gc in bacteria has the potential to degrade slowly, which might prolong bacterial environment survival. This phenomenon was previously examined and later formulated as the durable energy storage mechanism hypothesis. Although recent research has been warming to the hypothesis, experimental validation is still missing at current stage. In this review, we summarized recent progress of the hypothesis, provided a supporting mathematical model, and explored the technical pitfalls that shall be avoided in glycogen study.


Assuntos
Bactérias/crescimento & desenvolvimento , Glucose/metabolismo , Glicogênio/química , Trifosfato de Adenosina/metabolismo , Bactérias/química , Bactérias/metabolismo , Sequência de Carboidratos , Metabolismo Energético , Viabilidade Microbiana , Modelos Teóricos
6.
Carbohydr Polym ; 231: 115695, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31888803

RESUMO

Building blocks characterization is a significant approach for understanding the molecular structure of heparin and its derivatives. Nitrous acid (HONO) depolymerization of heparin generates oligosaccharides that maintain the epimerization conformation on C5 of the uronic acids, reflecting the authentic structure of the parental chain. HONO treatment at pH 1.5 selectively cleaves the bond between N-sulfated glucosamine and hexuronic acid, resulting mainly disaccharides, as well as tetra-, tri-, and mono-saccharides. The tetrasaccharides are derived from the structure of N-acetylated domains while tri-, and mono-saccharides are derived from the reducing or the non-reducing end of the heparin chain. The resulted oligosaccharides were separated and analyzed using a UHPLC-HILIC/WAX-MS method. We succeeded in the identification of 19 tetrasaccharides, 19 trisaccharides and 4 monosaccharides species, majority of which is structurally characterized. By comparing the theoretical possibilities and actual occurrence of the well-characterized tetrasaccharides, we demonstrated that the biosynthesis of heparin is a systematic process.


Assuntos
Heparina/química , Estrutura Molecular , Ácido Nitroso/química , Oligossacarídeos/química , Sequência de Carboidratos/genética , Cromatografia Líquida de Alta Pressão , Dissacarídeos/química , Glucosamina/química , Heparina Liase/química , Espectroscopia de Ressonância Magnética , Oligossacarídeos/genética , Polissacarídeo-Liase/química , Trissacarídeos/química
7.
Carbohydr Polym ; 229: 115473, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826443

RESUMO

The development of solubilizers with high efficiency, high safety and simple technology is one of the important fields in modern pharmaceutical industry. Our previous study found that vinegar baked Radix Bupleurum polysaccharides (VBCP) was a potential candidate. This study aimed to clarify which polysaccharide in VBCP had solubility enhancement effect and its solubilizing mechanism. Here, we reported that a novel acidic branched polysaccharide from VBCP, VBCP-3-A, which was non-toxic and had high solubility to baicalin and rhein. It was much better than that of Tween 80. The solubilization mechanism might be that VBCP-3-A self-assembled to form micelle-like aggregates in water, which can encapsulate water-insoluble constituents through the interaction of both hydrogen bonding and hydrophobic forces. in vivo pharmacokinetic study showed that VBCP-3-A increased Cmax and AUC (0-t) of baicalin and rhein. Those results suggested that VBCP-3-A was a potential solubilizer with high efficiency and high safety.


Assuntos
Bupleurum/química , Portadores de Fármacos/química , Polissacarídeos/química , Animais , Antraquinonas/química , Antraquinonas/farmacocinética , Sequência de Carboidratos , Linhagem Celular , Portadores de Fármacos/toxicidade , Flavonoides/química , Flavonoides/farmacocinética , Humanos , Masculino , Micelas , Raízes de Plantas/química , Polissacarídeos/toxicidade , Ratos Sprague-Dawley , Solubilidade
8.
Carbohydr Polym ; 229: 115462, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826478

RESUMO

This study aimed to investigate the physicochemical properties, health-promoting benefits and rheological properties of an EPS produced by a novel probiotic Pediococcus pentosaceus M41 isolated from a marine source. P. pentosaceus M41 was able to produce an EPS with average molecular weight of 682.07 kDa. EPS-M41 consisted of arabinose, mannose, glucose and galactose with a molar ratio of 1.2:1.8:15.1:1.0. EPS-M41 structure could be proposed as →3)α-D-Glc(1→2)ß-D-Man(1→2)α-D-Glc(1→6)α-D-Glc(1→4)α-D-Glc(1→4)α-D-Gal(1→ with arabinose linked at the terminals. At concentration of 10 mg.ml-1, the antioxidant capacity was 76.5% and 48.9% for DPPH and ABTS, respectively. EPS-M41 inhibited 86.8% and 90.8% of the α-amylase and α-glucosidase activities, respectively, at 100 µg.ml-1. A 77.5% and 46.4% of antitumor inhibition occurred by EPS-M41 against Caco-2 and MCF-7 cells, respectively. The apparent viscosity (ƞ) of all EPS-M41 solutions decreased with shear rate increases. Salt type and pH value had an impact on the rheological properties of EPS-M41.


Assuntos
Pediococcus pentosaceus/química , Polissacarídeos Bacterianos/farmacologia , Probióticos/química , Sequência de Carboidratos , Linhagem Celular Tumoral , Humanos , Peso Molecular , Polissacarídeos Bacterianos/química , Reologia , Substâncias Viscoelásticas/química , Substâncias Viscoelásticas/farmacologia , Viscosidade
9.
Nat Commun ; 10(1): 5567, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31804467

RESUMO

SPOR domains are widely present in bacterial proteins that recognize cell-wall peptidoglycan strands stripped of the peptide stems. This type of peptidoglycan is enriched in the septal ring as a product of catalysis by cell-wall amidases that participate in the separation of daughter cells during cell division. Here, we document binding of synthetic denuded glycan ligands to the SPOR domain of the lytic transglycosylase RlpA from Pseudomonas aeruginosa (SPOR-RlpA) by mass spectrometry and structural analyses, and demonstrate that indeed the presence of peptide stems in the peptidoglycan abrogates binding. The crystal structures of the SPOR domain, in the apo state and in complex with different synthetic glycan ligands, provide insights into the molecular basis for recognition and delineate a conserved pattern in other SPOR domains. The biological and structural observations presented here are followed up by molecular-dynamics simulations and by exploration of the effect on binding of distinct peptidoglycan modifications.


Assuntos
Parede Celular/química , Proteínas de Escherichia coli/química , Escherichia coli/química , Peptidoglicano/química , Domínios Proteicos , Bacillus subtilis/química , Bacillus subtilis/metabolismo , Sequência de Carboidratos , Parede Celular/metabolismo , Cristalografia por Raios X , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Lipoproteínas/química , Lipoproteínas/metabolismo , Simulação de Dinâmica Molecular , Peptidoglicano/metabolismo , Ligação Proteica , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/metabolismo
10.
Int J Mol Sci ; 21(1)2019 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-31877897

RESUMO

Gangliosides are sialic acid-containing glycosphingolipids, which are the most abundant family of glycolipids in eukaryotes. Gangliosides have been suggested to be important lipid molecules required for the control of cellular procedures, such as cell differentiation, proliferation, and signaling. GD1a is expressed in interstitial cells during ovarian maturation in mice and exogenous GD1a is important to oocyte maturation, monospermic fertilization, and embryonic development. In this context, GM1 is known to influence signaling pathways in cells and is important in sperm-oocyte interactions and sperm maturation processes, such as capacitation. GM3 is expressed in the vertebrate oocyte cytoplasm, and exogenously added GM3 induces apoptosis and DNA injury during in vitro oocyte maturation and embryogenesis. As a consequence of this, ganglioside GT1b and GM1 decrease DNA fragmentation and act as H2O2 inhibitors on germ cells and preimplantation embryos. This review describes the functional roles of gangliosides in spermatozoa, oocytes, and early embryonic development.


Assuntos
Blastocisto/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Gangliosídeo G(M3)/farmacologia , Oócitos/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Blastocisto/metabolismo , Sequência de Carboidratos , Feminino , Gangliosídeo G(M3)/química , Gangliosídeo G(M3)/metabolismo , Masculino
11.
Glycoconj J ; 36(6): 495-507, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31773366

RESUMO

Human ovarian cyst glycoproteins (HOC, cyst gps) isolated from pseudomucinous type of human ovarian cyst fluids is one of the richest and pioneer sources for studying biosynthesis, structures and functional roles of blood group ABH, Lea,b,x,y, sLea and sLex active glycoproteins. After 70+ years of exploration, four top highlights are shared. (i) an updated concept of glycotopes and their internal structures in cyst gps was composited; (ii) the unknown codes of new genes in secreted cyst gps were unlocked as Lex and Ley; (iii) recognition profiles of cyst glycans and a sialic acid-rich (18%) glycan with lectins and antibodies were shown. (iv) Co-expression of Blood Group A/ A-Leb/y and B/B-Leb/y active Glycotopes in the same glycan chains were isolated and illustrated. These are the most advanced achievements since 1980.


Assuntos
Sistema ABO de Grupos Sanguíneos/química , Gangliosídeos/química , Antígenos do Grupo Sanguíneo de Lewis/química , Polissacarídeos/química , Antígeno Sialil Lewis X/química , Sistema ABO de Grupos Sanguíneos/genética , Sequência de Carboidratos/genética , Gangliosídeos/genética , Glicoproteínas/química , Glicoproteínas/genética , Humanos , Antígenos do Grupo Sanguíneo de Lewis/genética , Polissacarídeos/genética , Ligação Proteica , Antígeno Sialil Lewis X/genética
12.
Anal Chim Acta ; 1091: 1-22, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31679562

RESUMO

N-glycosylation is one of the most frequently occurring protein post-translational modifications (PTMs) with broad cellular, physiological and pathological relevance. Mass spectrometry-based N-glycomics has become the state-of-the-art instrumental analytical pipeline for sensitive, high-throughput and comprehensive characterization of N-glycans and N-glycomes. Improvement and new development of methods in N-glycan release, enrichment, derivatization, isotopic labeling, separation, ionization, MS, tandem MS and informatics accompany side-by-side wider and deeper application. This review provides a comprehensive update of mass spectrometry-based qualitative and quantitative N-glycomics in the years of 2017-2018.


Assuntos
Glicômica/métodos , Polissacarídeos/análise , Espectrometria de Massas em Tandem/métodos , Animais , Sequência de Carboidratos , Linhagem Celular , Humanos , Vírus da Influenza A Subtipo H9N2/química
13.
Biomater Sci ; 7(12): 4848-4872, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31650998

RESUMO

Glycopolymers are an important class of biomaterials which include carbohydrate moieties in their polymer structure. In addition to biological research on the interactions of glycopolymers with lectin-carbonate, glycopolymers have recently been used as a new synthetic biomaterial for direct therapeutic methods, medical adhesives, and biosensors. Thus, a comprehensive understanding of new advances in glycopolymer research is essential for the next level of biomaterial studies. This review article highlights commonly used glycopolymer synthesis methods and biomedical applications thereof. Glycopolymers can be synthesized by modern polymerization methods that can control the molecular weight, molecular weight distribution, chemical functionality, and polymer architecture. The polymerizations include free radical polymerization, atom transfer radical polymerization, reversible addition-fragmentation chain-transfer polymerization, and nitroxide-mediated polymerization. Because the carbohydrate-lectin interactions with glycopolymers are involved in many biological processes, carbohydrates containing glycopolymers are used in (1) fundamental studies to understand the specificity and strength of biological binding, (2) controllable interactions to prevent microorganism adhesion to human cells, (3) large scale bulk adhesives for medical applications, (4) biocompatible therapeutic nanoparticles, (5) direct drug delivery vehicles, and (6) precise quantitative measurement of biosensor materials that can detect physiological signals.


Assuntos
Biopolímeros/química , Carboidratos/síntese química , Aderência Bacteriana/efeitos dos fármacos , Biopolímeros/farmacologia , Sequência de Carboidratos , Carboidratos/química , Carboidratos/farmacologia , Humanos , Peso Molecular
14.
Carbohydr Res ; 486: 107831, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31627049

RESUMO

P. mirabilis strains Kro 45 and Kwy 46 were isolated from the pus and the muscular fluid, respectively, of a hospitalized 61-year-old female in Lódz, Poland. Both strains demonstrated a good swarming ability on a solid medium, and the Dienes test for differentiation of swarming strains indicated their identity. The strains were serologically identical and did not belong to any of the known Proteus O1-O81 serogroups. In this work, we studied the O-specific polysaccharide (O antigen) of P. mirabilis Kwy46, which defines the immunospecificity of the strain. The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide, and the following structure of its oligosaccharide repeat (O-unit) was established by sugar analysis along with 1D and 2D 1H and 13C NMR spectroscopy: where (S)-lac indicates an (S)-1-carboxyethyl group [an (S)-lactic acid residue], which forms an ether with a GlcNAc residue (so called glycolactilic acid). This structure is unique among Proteus O-polysaccharides but shares a trisaccharide fragment with that of P. mirabilis O5. Studies of the cross-reactivity between P. mirabilis Kwy 46 O antiserum/lipopolysaccharide and Proteus O1-O81 lipopolysaccharides/O antisera allowed identification of a putative Kwy 46 O-antigen epitope. Based on the data obtained, it is proposed to create a new O82 serogroup within the genus Proteus represented by the studied P. mirabilis isolates.


Assuntos
Antígenos O/química , Proteus mirabilis/química , Proteus mirabilis/isolamento & purificação , Sequência de Carboidratos , Feminino , Humanos , Pessoa de Meia-Idade , Antígenos O/imunologia , Polônia , Proteus mirabilis/imunologia , Sorogrupo
15.
Carbohydr Res ; 486: 107824, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31585319

RESUMO

The total chemical synthesis of lacto-N-tetraose (LNT) has been completed using both convergent and linear strategies. Similarly to that of our previous HMO syntheses, the donor-acceptor protecting-leaving group combinations were found to be of paramount significance to achieving successful glycosylations and minimizing side reactions.


Assuntos
Leite Humano/química , Oligossacarídeos/química , Oligossacarídeos/síntese química , Sequência de Carboidratos , Técnicas de Química Sintética , Humanos
16.
Food Chem Toxicol ; 133: 110778, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31472224

RESUMO

This study was to investigate the structure of a polysaccharide fraction from the Fortunella margarita and the relationship between its digestibility and structure. A novel polysaccharide fraction extracted by graded precipitation at ethanol concentrations of 20% from F. margarita (named FP20) comprised mainly glucose, galactose, and mannose. The unit composition was →4)-ß-Glcp-(1 → 2)-α-Glcp-(1 → 2)-α-Galp-(1 → 4)-α-Galp-(1→ bone, and in →2)-α-Galp-(1→) with a branching point at C6 of ß-Manp. FP20 was identified as a mannogalactoglucan with a different monosaccharide composition ratio and side-chain sugar residues compared with other plant polysaccharides. Moreover, FP20 had a spherical aggregations by atomic force microscope test. FP20 had an island-shaped structures with a smooth surface revealed by field emission scanning electron microscopy. Furthermore, in vitro digestive test, FP20 was resistance to a digestion system of saliva-gastric-small intestinal. The digestibility of FP20 was related to its backbone unit, structure and tight, uniform, and spherical chain conformation in aqueous.


Assuntos
Digestão , Galactanos/química , Glucanos/química , Rutaceae/química , Sequência de Carboidratos , Suco Gástrico/química , Hidrólise , Secreções Intestinais/química , Manose/química , Peso Molecular , Saliva/química
17.
Carbohydr Polym ; 224: 115146, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472868

RESUMO

Fucosylated glycosaminoglycan (FG), a glycosaminoglycan derivative containing distinct sulfated fucose (FucS) branches, displays potent anticoagulant activity by inhibiting the intrinsic tenase complex (iXase). Herein, AmFG, SvFG and HaFG from three species of sea cucumbers were isolated and depolymerized by ß-eliminative cleavage. Three series of fragments, A1-A4, S1-S4 and H1-H4, were purified from the depolymerized FGs. Based on structural analysis of these fragments, three FGs were deduced as -{→4)-[L-FucS-α(1→3)]-D-GlcA-ß(1→3)-D-GalNAc4S6S-ß(1}n-. The structures differed in sulfation types of FucS, namely, most of FucS in AmFG was Fuc3S4S, but the FucS in SvFG was Fuc2S4S, while the FucS in HaFG was Fuc3S4S, Fuc2S4S and Fuc4S. However, all FucS branches attached to C-3 of GlcA as monosaccharides. Anticoagulant and anti-iXase assays showed the octasaccharide is the minimum fragment for potent anticoagulant activity via anti-iXase irrespective of FucS types. Among FG fragments with same degree of polymerization, oligosaccharides containing Fuc2S4S had more potent anti-iXase activity.


Assuntos
Inibidores de Cisteína Proteinase/química , Inibidores de Cisteína Proteinase/farmacologia , Fucose/química , Glicosaminoglicanos/química , Glicosaminoglicanos/farmacologia , Proteínas de Neoplasias/antagonistas & inibidores , Anticoagulantes/química , Anticoagulantes/farmacologia , Sequência de Carboidratos , Cisteína Endopeptidases
18.
Carbohydr Res ; 484: 107781, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31476560

RESUMO

A novel strain of Lactobacillus mucosae was isolated from a faecal sample of an individual who had adhered to a strict vegetarian diet for nine years. The strain displayed a ropy character when grown on plates and generated a relatively small amount (62 mg/L) of an exopolysaccharide (EPS) when grown in broth culture. The EPS eluted from a size exclusion chromatography column as a single band with a weight average molecular mass of 1.51 × 104 g/mol. Monomer analysis and sugar absolute configuration analysis confirmed that the EPS was a D-galactan. Using linkage analysis in combination with 1D and 2D-NMR spectroscopy, with spectra being recorded for both the native EPS and for the products generated by Smith degradation of the EPS, the following structure was determined for the repeat unit of the polysaccharide: This is a novel D-galactan and represents the first structure for an EPS produced by a strain of Lactobacillus mucosae to be reported.


Assuntos
Fezes/microbiologia , Galactanos/química , Lactobacillus/isolamento & purificação , Sequência de Carboidratos , Galactanos/isolamento & purificação , Humanos , Lactobacillus/genética , Lactobacillus/metabolismo , Espectroscopia de Ressonância Magnética , Peso Molecular , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/isolamento & purificação
19.
Int J Biol Macromol ; 141: 756-764, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31479666

RESUMO

For a more insightful investigation into the specificity of bacterial heparinase I, a series of structurally well-defined heparin oligosaccharides was synthesized using a highly efficient chemoenzymatic strategy. Apart from the primary cleavage site, five glycosidic linkages of oligosaccharides with varying modifications to obtain secondary cleavage sites were degraded by a high concentration of heparinase I. The reactivity of linkages toward heparinase I was not entirely dependent on the 2-O-sulfated iduronic acid being cleaved or the neighboring 6-O-sulfated glucosamine residues, but it was dependent on higher degrees of sulfation of oligosaccharides and indispensable N-substituted glucosamine adjacent to the cleavable linkage. Moreover, the enzyme demonstrated less preferential cleavage toward glycosidic linkages containing glucuronic acid than those containing iduronic acid of the counterpart oligosaccharides. Biolayer interferometry revealed differences in reactivity that are not completely consistent with different affinities of substrates to enzyme. Our study presented accurate information on the cleavage promiscuity of heparinase I that is crucial for heparin depolymerization.


Assuntos
Heparina Liase/metabolismo , Heparina/química , Heparina/metabolismo , Oligossacarídeos/química , Sítios de Ligação , Sequência de Carboidratos , Glicosilação , Cinética , Peso Molecular , Especificidade por Substrato
20.
Carbohydr Res ; 484: 107780, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31479870

RESUMO

This work combined three classes of compounds in the same molecule "amino triazole-glycoside" and developed a convenient method for the synthesis of this type of compound via a one-pot two step reaction. Alkylation of amine derivatives with propargyl bromide to give propargylamine was performed in the first step subsequently followed by a 'click' reaction with various ß-azido-glycosides in the presence of CuI in aqueous solution to provide ß-amino triazole-glycosides. Thirty-two examples of glycosides were obtained in moderate to good yield using this one-pot procedure.


Assuntos
Química Click/métodos , Glicosídeos/síntese química , Alquilação , Aminas/química , Sequência de Carboidratos , Glicosídeos/química , Pargilina/análogos & derivados , Pargilina/química , Propilaminas/química , Triazóis/química
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