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1.
J Am Chem Soc ; 146(27): 18427-18439, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38946080

RESUMEN

Pseudomonas aeruginosa bacteria are becoming increasingly resistant against multiple antibiotics. Therefore, the development of vaccines to prevent infections with these bacteria is an urgent medical need. While the immunological activity of lipopolysaccharide O-antigens in P. aeruginosa is well-known, the specific protective epitopes remain unidentified. Herein, we present the first chemical synthesis of highly functionalized aminoglycoside trisaccharide 1 and its acetamido derivative 2 found in the P. aeruginosa serotype O5 O-antigen. The synthesis of the trisaccharide targets is based on balancing the reactivity of disaccharide acceptors and monosaccharide donors. Glycosylations were analyzed by quantifying the reactivity of the hydroxyl group of the disaccharide acceptor using the orbital-weighted Fukui function and dual descriptor. The stereoselective formation of 1,2-cis-α-fucosylamine linkages was achieved through a combination of remote acyl participation and reagent modulation. The simultaneous SN2 substitution of azide groups at C2' and C2″ enabled the efficient synthesis of 1,2-cis-ß-linkages for both 2,3-diamino-D-mannuronic acids. Through a strategic orthogonal modification, the five amino groups on target trisaccharide 1 were equipped with a rare acetamidino (Am) and four acetyl (Ac) groups. Glycan microarray analyses of sera from patients infected with P. aeruginosa indicated that trisaccharides 1 and 2 are key antigenic epitopes of the serotype O5 O-antigen. The acetamidino group is not an essential determinant of antibody binding. The ß-D-ManpNAc3NAcA residue is a key motif for the antigenicity of serotype O5 O-antigen. These findings serve as a foundation for the development of glycoconjugate vaccines targeting P. aeruginosa serotype O5.


Asunto(s)
Aminoglicósidos , Antígenos O , Pseudomonas aeruginosa , Trisacáridos , Pseudomonas aeruginosa/inmunología , Antígenos O/química , Antígenos O/inmunología , Trisacáridos/química , Trisacáridos/inmunología , Trisacáridos/síntesis química , Aminoglicósidos/química , Aminoglicósidos/síntesis química , Aminoglicósidos/inmunología
2.
J Agric Food Chem ; 72(25): 14191-14198, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38878091

RESUMEN

3-Fucosyllactose (3-FL), an important fucosylated human milk oligosaccharide in breast milk, offers numerous health benefits to infants. Previously, we metabolically engineered Escherichia coli BL21(DE3) for the in vivo biosynthesis of 3-FL. In this study, we initially optimized culture conditions to double 3-FL production. Competing pathway genes involved in in vivo guanosine 5'-diphosphate-fucose biosynthesis were subsequently inactivated to redirect fluxes toward 3-FL biosynthesis. Next, three promising transporters were evaluated using plasmid-based or chromosomally integrated expression to maximize extracellular 3-FL production. Additionally, through analysis of α1,3-fucosyltransferase (FutM2) structure, we identified Q126 residues as a highly mutable residue in the active site. After site-saturation mutation, the best-performing mutant, FutM2-Q126A, was obtained. Structural analysis and molecular dynamics simulations revealed that small residue replacement positively influenced helical structure generation. Finally, the best strain BD3-A produced 6.91 and 52.1 g/L of 3-FL in a shake-flask and fed-batch cultivations, respectively, highlighting its potential for large-scale industrial applications.


Asunto(s)
Escherichia coli , Fucosiltransferasas , Ingeniería Metabólica , Trisacáridos , Escherichia coli/genética , Escherichia coli/metabolismo , Trisacáridos/metabolismo , Trisacáridos/biosíntesis , Trisacáridos/química , Fucosiltransferasas/genética , Fucosiltransferasas/metabolismo , Humanos , Oligosacáridos
3.
Phys Chem Chem Phys ; 26(19): 14160-14170, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38712976

RESUMEN

Protonated ions of fucose-containing oligosaccharides are prone to undergo internal glycan rearrangement which results in chimeric fragments that obfuscate mass-spectrometric analysis. Lack of accessible tools that would facilitate systematic analysis of glycans in the gas phase limits our understanding of this phenomenon. In this work, we use density functional theory modeling to interpret cryogenic IR spectra of Lewis a and blood group type H1 trisaccharides and to establish whether these trisaccharides undergo the rearrangement during gas-phase analysis. Structurally unconstrained search reveals that none of the parent ions constitute a thermodynamic global minimum. In contrast, predicted collision cross sections and anharmonic IR spectra provide a good match to available experimental data which allowed us to conclude that fucose migration does not occur in these antigens. By comparing the predicted structures with those obtained for Lewis x and blood group type H2 epitopes, we demonstrate that the availability of the mobile proton and a large difference in the relative stability of the parent ions and rearrangement products constitute the prerequisites for the rearrangement reaction.


Asunto(s)
Antígenos del Grupo Sanguíneo de Lewis , Antígenos del Grupo Sanguíneo de Lewis/química , Epítopos/química , Termodinámica , Polisacáridos/química , Teoría Funcional de la Densidad , Antígenos de Grupos Sanguíneos/química , Espectrofotometría Infrarroja , Oligosacáridos/química , Trisacáridos/química
4.
ACS Sens ; 9(6): 2806-2814, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38810251

RESUMEN

Bacterial infections lack reliable, specific, and quick detection methods, which incur substantial costs to patients and caretakers. Our team conjugated the FDA-approved fluorescent dye indocyanine green (ICG) with a maltotriose sugar, resulting in two highly specific imaging agents (ICG-DBCO-1-Maltotriose and ICG-Amide-1-Maltotriose) for detecting bacterial infections. We then evaluated the two derivatives using fluorescence imaging (FLI), bioluminescence imaging (BLI), and photoacoustic imaging (PAI) in bacterial infection murine models. Our findings indicate that both imaging agents can correlate with and reliably detect the infection site using FLI and PAI for both Gram-negative and Gram-positive strains, with various bacterial loads. Furthermore, the differences in pharmacokinetic (PK) properties between the two agents allow for one to be used for immediate imaging (2-4 h postinjection), while the other is more effective for longitudinal studies (18-40 h postinjection).


Asunto(s)
Verde de Indocianina , Trisacáridos , Verde de Indocianina/química , Animales , Trisacáridos/química , Ratones , Colorantes Fluorescentes/química , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/diagnóstico por imagen , Imagen Óptica , Técnicas Fotoacústicas/métodos , Mediciones Luminiscentes/métodos , Femenino
5.
J Mass Spectrom ; 59(5): e5026, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38656572

RESUMEN

Identification and specific quantification of isomers in a complex biological matrix by mass spectrometry alone is not an easy task due to their identical chemical formula and therefore their same mass-to-charge ratio (m/z). Here, the potential of direct introduction combined with ion mobility-mass spectrometry (DI-IM-MS) for rapid quantification of isomers as human milk oligosaccharides (HMOs) was investigated. Differences in HMO profiles between various analyzed breast milk samples were highlighted using the single ion mobility monitoring (SIM2) acquisition for high ion mobility resolution detection. Furthermore, the Se+ (secretor) or Se- (non-secretor) phenotype could be assigned to breast milk samples studied based on their HMO contents, especially on the response of 2'-fucosyllactose (2'-FL) and lacto-N-fucopentaose I (LNFP I). The possibility of quantifying a specific isomer in breast milk by DI-IM-MS was also investigated. The standard addition method allowed the determination of the 2'-FL despite the presence of other oligosaccharides, including 3-fucosyllactose (3-FL) isomer in breast milk. This proof-of-concept study demonstrated the high potential of such an approach for the rapid and convenient quantification of isomers in complex mixtures.


Asunto(s)
Espectrometría de Movilidad Iónica , Leche Humana , Oligosacáridos , Trisacáridos , Leche Humana/química , Humanos , Trisacáridos/análisis , Trisacáridos/química , Oligosacáridos/análisis , Oligosacáridos/química , Isomerismo , Femenino , Espectrometría de Movilidad Iónica/métodos , Espectrometría de Masas/métodos
6.
Chembiochem ; 25(9): e202400026, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38506247

RESUMEN

In this work, we have discovered that the Gal-α-(1→3)-Gal-ß-(1→3)-GlcNAc trisaccharide, a fragment of the B antigen Type-1, is a new ligand of two C-type lectin receptors (CLRs) i. e. DCAR and Mincle which are key players in different types of autoimmune diseases. Accordingly, we report here on a straightforward methodology to access pure Gal-α-(1→3)-Gal-ß-(1→3)-GlcNAc trisaccharide. A spacer with a terminal primary amine group was included at the reducing end of the GlcNAc residue thus ensuring the further functionalization of the trisaccharide Gal-α-(1→3)-Gal-ß-(1→3)-GlcNAc.


Asunto(s)
Lectinas Tipo C , Receptores Inmunológicos , Trisacáridos , Lectinas Tipo C/metabolismo , Lectinas Tipo C/química , Trisacáridos/química , Trisacáridos/síntesis química , Ligandos , Estereoisomerismo , Humanos , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo
7.
J Org Chem ; 88(13): 8770-8780, 2023 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-37340701

RESUMEN

Herein, we report a concise synthetic approach for the first total synthesis of a pentasaccharide repeating unit of Acinetobacter baumannii K11 capsular polysaccharides containing a rare sugar 6-deoxy-l-talose. The pentasaccharide was synthesized in a convergent manner using a [3 + 2] block glycosylation strategy. During this synthetic strive, we used a 2,2,2-trichloroethoxycarbonyl (Troc)-protected monosaccharide unit to achieve a high yield during the glycosylation to synthesize a trisaccharide, and chemoselective deprotection of the Troc group from the trisaccharide was carried out under a mild, pH-neutral condition, keeping the O-glycosidic bond, azido, and acid/base sensitive group intact. A thiotolylglycoside disaccharide donor containing 6-deoxy-l-talose was synthesized for the first time by the armed-disarmed glycosylation method between two thiotolylglycosides.


Asunto(s)
Acinetobacter baumannii , Acinetobacter baumannii/química , Secuencia de Carbohidratos , Polisacáridos/química , Oligosacáridos/química , Trisacáridos/química , Polisacáridos Bacterianos/química
8.
Food Chem ; 420: 136144, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37060669

RESUMEN

Fucosylated oligosaccharides have promising prospects in various fields. In this study, a fucosylated trisaccharide (GFG) was separated from the acidolysis products of exopolysaccharides from Clavibacter michiganensis M1. Structural characterization demonstrated that GFG consists of glucose, galactose, and fucose, with a molecular weight of 488 Da. Nuclear magnetic resonance analysis showed that it has a different structure than that of 2'-fucosyllactose (2'-FL), even though they have the same monosaccharide composition. In vitro prebiotic experiments were conducted to evaluate the differences in the utilization of three selected carbohydrates by fourteen bacterial strains. In comparison with 2'-FL, GFG could be utilized by more beneficial bacteria, leading to generate more short-chain fatty acids. Moreover, GFG could not promote the proliferation of Escherichia coli. This work describes a novel fucosylated oligosaccharide and its preparation method, and the obtained trisaccharide may serve as a promising candidate for fucosylated human milk oligosaccharides.


Asunto(s)
Trisacáridos , Leche Humana/química , Trisacáridos/química , Escherichia coli , Fucosa , Glicosilación
9.
Angew Chem Int Ed Engl ; 62(1): e202211940, 2023 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-36350770

RESUMEN

We herein report the first total synthesis of the Streptococcus pneumoniae serotype 1 (Sp1) oligosaccharide, a unique zwitterionic capsular polysaccharide carrying labile O-acetyl esters. The target oligosaccharides, featuring rare α-2,4-diamino-2,4,6-trideoxy galactose (AAT) and α-galacturonic acids, were assembled up to the 9-mer level, in a highly stereoselective manner using trisaccharide building blocks. The lability of the O-acetyl esters imposed a careful deprotection scheme to prevent migration and hydrolysis. The migration was investigated in detail at various pD values using NMR spectroscopy, to show that migration and hydrolysis of the C-3-O-acetyl esters readily takes place under neutral conditions. Structural investigation showed the oligomers to adopt a right-handed helical structure with the acetyl esters exposed on the periphery of the helix in close proximity of the neighboring AAT residues, thereby imposing conformational restrictions on the AATα1-4GalA(3OAc) glycosidic linkages, supporting the helical shape of the polysaccharide, that has been proposed to be critical for its unique biological activity.


Asunto(s)
Polisacáridos Bacterianos , Streptococcus pneumoniae , Polisacáridos Bacterianos/química , Oligosacáridos , Trisacáridos/química , Glicósidos
10.
Int J Mol Sci ; 23(20)2022 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-36293535

RESUMEN

In this work, the trisaccharide isomelezitose was overproduced from sucrose using a biocatalyst based on immobilized Escherichia coli cells harbouring the α-glucosidase from the yeast Metschnikowia reukaufii, the best native producer of this sugar described to date. The overall process for isomelezitose production and purification was performed in three simple steps: (i) oligosaccharides synthesis by alginate-entrapped E. coli; (ii) elimination of monosaccharides (glucose and fructose) using alginate-entrapped Komagataella phaffii cells; and (iii) semi-preparative high performance liquid chromatography under isocratic conditions. As result, approximately 2.15 g of isomelezitose (purity exceeding 95%) was obtained from 15 g of sucrose. The potential prebiotic effect of this sugar on probiotic bacteria (Lactobacillus casei, Lactobacillus rhamnosus and Enterococcus faecium) was analysed using in vitro assays for the first time. The growth of all probiotic bacteria cultures supplemented with isomelezitose was significantly improved and was similar to that of cultures supplemented with a commercial mixture of fructo-oligosaccharides. In addition, when isomelezitose was added to the bacteria cultures, the production of organic acids (mainly butyrate) was significantly promoted. Therefore, these results confirm that isomelezitose is a potential novel prebiotic that could be included in healthier foodstuffs designed for human gastrointestinal balance maintenance.


Asunto(s)
Prebióticos , Probióticos , Humanos , Escherichia coli/genética , Alginatos , alfa-Glucosidasas , Oligosacáridos , Trisacáridos/química , Monosacáridos , Azúcares , Sacarosa , Glucosa , Fructosa , Butiratos
11.
J Bacteriol ; 204(9): e0025322, 2022 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-35997505

RESUMEN

Bacillus anthracis elaborates a secondary cell wall polysaccharide (SCWP) made of 6 to 12 trisaccharide units. Pyruvyl and acetyl substitutions of the distal unit are prerequisites for the noncovalent retention of 22 secreted Bacillus S-layer (Bsl)-associated proteins bearing an S-layer homology (SLH) domain. Surface display of Bsl proteins contributes to cell separation as well as virulence. Earlier work suggested that TagO initiates the synthesis of SCWP while GneY and GneZ, two UDP-GlcNAc 2-epimerases, synthesize ManNAc that is later incorporated in the repeat unit (→4)-ManNAc-(ß1→4)-GlcNAc-(ß1→6)-GlcNAc-(α1→). In organisms that synthesize wall teichoic acid, TagA catalysts have been shown to form the glycosidic bond ManNAc-(ß1→4)-GlcNAc. Here, we show that genes bas2675 and bas5272, predicted to encode glycosyltransferases of the WecB/TagA/CpsF family (PFAM03808; CAZy GT26), are required for B. anthracis SCWP synthesis and S-layer assembly. Similar to tagO or gneY gneZ mutants, B. anthracis strains depleted of tagA1 (bas5272) cannot maintain cell shape, support vegetative growth, or synthesize SCWP. Expression of tagA2 (bas2675), or Staphylococcus aureus tagA on a plasmid, rescues the nonviable tagA1 mutant. We propose that TagA1 and TagA2 fulfill overlapping and key glycosyltransferase functions for the synthesis of repeat units of the SCWP of B. anthracis. IMPORTANCE Glycosyltransferases (GTs) catalyze the transfer of sugar moieties from activated donor molecules to acceptor molecules to form glycosidic bonds using a retaining or inverting mechanism. Based on the structural relatedness of their catalytic and carbohydrate-binding modules, GTs have been grouped into 115 families in the Carbohydrate-Active EnZyme (CAZy) database. For complex products, the functional assignment of GTs remains highly challenging without the knowledge of the chemical structure of the assembled polymer. Here, we propose that two uncharacterized GTs of B. anthracis belonging to the WecB/TagA/CpsF family incorporate ManNAc in repeat units of the secondary cell wall polymer of bacilli species.


Asunto(s)
Bacillus anthracis , Bacillus anthracis/metabolismo , Proteínas Bacterianas/metabolismo , Pared Celular/metabolismo , Glicosiltransferasas/genética , Glicosiltransferasas/metabolismo , Glicoproteínas de Membrana/metabolismo , Polímeros , Polisacáridos/metabolismo , Azúcares/metabolismo , Trisacáridos/química , Uridina Difosfato/análisis , Uridina Difosfato/metabolismo
12.
Angew Chem Int Ed Engl ; 61(33): e202206128, 2022 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-35695834

RESUMEN

Anomeric stereocontrol is usually one of the major issues in the synthesis of complex carbohydrates, particularly those involving ß-configured 2,6-dideoxyglycoside and d/l-rhamnoside moieties. Herein, we report that 2-(diphenylphosphinoyl)acetyl is highly effective as a remote stereodirecting group in the direct synthesis of these challenging ß-glycosides under mild conditions. A deoxy-trisaccharide as a mimic of the sugar chain of landomycin E was prepared stereospecifically in high yield. The synthetic potential was also highlighted in the synthesis of Citrobacter freundii O-antigens composed of a [→4)-α-d-Manp-(1→3)-ß-d-Rhap(1→4)-ß-d-Rhap-(1→] repeating unit, wherein the convergent assembly up to a nonasaccharide was realized with a strongly ß-directing trisaccharide donor. Variable-temperature NMR studies indicate the presence of intermolecular H-bonding between the donor and the bulky acceptor as direct spectral evidence in support of the concept of hydrogen-bond-mediated aglycone delivery.


Asunto(s)
Glicósidos , Oligosacáridos , Secuencia de Carbohidratos , Carbohidratos , Glicósidos/química , Antígenos O/química , Oligosacáridos/química , Trisacáridos/química
13.
Talanta ; 243: 123353, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35248944

RESUMEN

Globotriose (Gal-α1, 4-Gal-ß1, 4-Glc) is involved in binding with Shiga toxins (Stxs) produced by Shigella dysenteriae and certain pathogenic Escherichia coli strains which could cause severe gastroenteritis and hemolytic uremic syndrome (HUS). Thus, this trisaccharide group and its derivatives provide potentials in the development of carbohydrate-based diagnostic and therapeutic reagents against bacterial infection. Instead of the tedious chemical synthesis of globotriose or its glycoconjugates, we reported a multi-step (step-wise) enzymatic synthesis system containing glucosyltransferase (ApNGT, E.C. 4.3.3.5), ß-1, 4-galactosyltransferase (LgtB, E.C. 2.4.1.22) and α-1, 4-galactosyltransferase (LgtC, E.C. 2.4.1.44) to produce globotriose-containing glycopeptides. In addition, based on the specific binding between Stxs and globotriose, a cost-efficient, convenient, ultra-sensitive and specific colorimetric biosensor was further constructed to detect Stxs using glycoconjugated Au@Fe-TFPA-COP (globotriose@Au@Fe-TFPA-COP) as a nanoenzyme catalyst. We estimate that this method conveniently applied in the detection of Stx-producing bacteria and associated infectious diseases.


Asunto(s)
Técnicas Biosensibles , Toxinas Shiga , Colorimetría , Péptidos , Trisacáridos/química
14.
Carbohydr Res ; 514: 108543, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35316645

RESUMEN

The trisaccharide, prop-2-ynyl 5-acetamido-3,5-dideoxy-d-glycero-α-d-galacto-2-nonulopyranosylonic acid-(2 â†’ 3)-ß-d-galactopyranosyl-(1 â†’ 4)-2-acetamido-2-deoxy-ß-d-glucopyranoside (9) has been efficiently synthesized in a few steps without the need of conformationally constrained glycosyl donors and acceptors or enzymes. First, using the known prop-2-ynyl 2-acetamido-2-deoxy-6-O-tert-butyldiphenylsilyl-ß-d-glucopyranoside as acceptor (2) and the peracetylated galactosyl trichloroacetimidate (3) as glycosyl donor, followed by protecting groups manipulation, prop-2-ynyl (6-O-tert-butyldiphenylsilyl-ß-d-galactopyranosyl)-(1 â†’ 4)-2-acetamido-2-deoxy-6-O-tert-butyldiphenylsilyl-ß-d-glucopyranoside (6) was synthesized with exclusive O-4 regioselectivity due to steric hindrance of the upper face of the acceptor at O-3. Sialylation with the thiophenyl glycosyl donor (7) afforded the desired trisaccharide with the shortest number of steps and in higher overall yield than previously reported methodologies. The direct use of minimally protected N-acetyl-lactosamine acceptor (6) was critical for the efficient synthesis of the title compound. The propargylic aglycone is suitable for chemical ligation using click chemistry as reported for its (2 â†’ 6) sialylated analog.


Asunto(s)
Trisacáridos , Amino Azúcares , Conformación de Carbohidratos , Secuencia de Carbohidratos , Trisacáridos/química
15.
Mar Drugs ; 20(3)2022 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-35323458

RESUMEN

Alginate oligosaccharides (AOS) have many biological activities and significant applications in prebiotics, nutritional supplements, and plant growth development. Alginate lyases have unique advantages in the preparation of AOS. However, only a limited number of alginate lyases have been so far reported to have potentials in the preparation of AOS with specific degrees of polymerization. Here, an alginate-degrading strain Pseudoalteromonasarctica M9 was isolated from Sargassum, and five alginate lyases were predicted in its genome. These putative alginate lyases were expressed and their degradation products towards sodium alginate were analyzed. Among them, AlyM2 mainly generated trisaccharides, which accounted for 79.9% in the products. AlyM2 is a PL6 lyase with low sequence identity (≤28.3%) to the characterized alginate lyases and may adopt a distinct catalytic mechanism from the other PL6 alginate lyases based on sequence alignment. AlyM2 is a bifunctional endotype lyase, exhibiting the highest activity at 30 °C, pH 8.0, and 0.5 M NaCl. AlyM2 predominantly produces trisaccharides from homopolymeric M block (PM), homopolymeric G block (PG), or sodium alginate, with a trisaccharide production of 588.4 mg/g from sodium alginate, indicating its promising potential in preparing trisaccharides from these polysaccharides.


Asunto(s)
Alginatos/química , Proteínas Bacterianas , Polisacárido Liasas , Pseudoalteromonas/enzimología , Sargassum/microbiología , Trisacáridos/química , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Genoma Bacteriano , Polisacárido Liasas/química , Polisacárido Liasas/genética , Polisacárido Liasas/metabolismo , Pseudoalteromonas/genética , Pseudoalteromonas/aislamiento & purificación , ARN Ribosómico 16S
16.
Carbohydr Res ; 512: 108515, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35134680

RESUMEN

A library of sixteen compounds, 1-16, comprising all (mono-, di-, and tri-) 2-fluoro-2-deoxy-derivatives of the N-glycan core trimannoside α-D-Man-(1 â†’ 3)-[α-D-Man-(1 â†’ 6)]-D-Man, including the corresponding 2-fluoro-2-deoxy disaccharide part structures and the non-fluorinated parent compounds, have been synthesized as their α-methyl glycosides for use as tools in 19F NMR-based lectin-carbohydrate interaction studies. Two methyl 2-fluoro-2-deoxy-mannoside acceptors, 21 (3-OH) and 22 (6-OH), were constructed and used in combination with the corresponding non-fluorinated mannose acceptors, 24 (6-OH) and 25 (3-OH), the 2-fluoro-2-deoxy mannosyl bromide donor 18 and the non-fluorinated bromide donor 23 to efficiently afford the target di-and trisaccharides (disaccharides, 2-3 steps, 47-66% overall yield; trisaccharides, 4 steps, 25-40% overall yield).


Asunto(s)
Glicósidos , Trisacáridos , Conformación de Carbohidratos , Disacáridos , Humanos , Espectroscopía de Resonancia Magnética , Manosa , Trisacáridos/química
17.
Mol Biotechnol ; 64(1): 75-89, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34542815

RESUMEN

Xylooligosaccharides having various degrees of polymerization such as xylobiose, xylotriose, and xylotetraose positively affect human health by interacting with gut proteins. The present study aimed to identify proteins present in gut microflora, such as xylosidase, xylulokinase, etc., with the help of retrieved whole-genome annotations and find out the mechanistic interactions of those with the above substrates. The 3D structures of proteins, namely Endo-1,4-beta-xylanase B (XynB) from Lactobacillus brevis and beta-D-xylosidase (Xyl3) from Bifidobacterium adolescentis, were computationally predicted and validated with the help of various bioinformatics tools. Molecular docking studies identified the effectual binding of these proteins to the xylooligosaccharides, and the stabilities of the best-docked complexes were analyzed by molecular dynamic simulation. The present study demonstrated that XynB and Xyl3 showed better effectual binding toward Xylobiose with the binding energies of - 5.96 kcal/mol and - 4.2 kcal/mol, respectively. The interactions were stabilized by several hydrogen bonding having desolvation energy (- 6.59 and - 7.91). The conformational stabilities of the docked complexes were observed in the four selected complexes of XynB-xylotriose, XynB-xylotetraose, Xyl3-xylobiose, and Xyn3-xylotriose by MD simulations. This study showed that the interactions of these four complexes are stable, which means they have complex metabolic activities among each other. Extending these studies of understanding, the interaction between specific probiotics enzymes and their ligands can explore the detailed design of synbiotics in the future.


Asunto(s)
Bifidobacterium adolescentis/metabolismo , Glucuronatos/metabolismo , Levilactobacillus brevis/metabolismo , Oligosacáridos/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Bifidobacterium adolescentis/genética , Biología Computacional , Disacáridos/química , Disacáridos/metabolismo , Endo-1,4-beta Xilanasas/química , Endo-1,4-beta Xilanasas/genética , Genoma Bacteriano/genética , Glucuronatos/química , Humanos , Levilactobacillus brevis/genética , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Oligosacáridos/química , Probióticos/metabolismo , Trisacáridos/química , Trisacáridos/metabolismo , Xilosidasas/química , Xilosidasas/genética
18.
Carbohydr Polym ; 275: 118684, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34742414

RESUMEN

Bioconversion of lignocellulosic biomass into value-added products relies on polysaccharides depolymerization by carbohydrate active enzymes. This work reports biochemical characterization of Paludibacter propionicigenes xylanase from GH10 (PpXyn10A) and its application for enzymatic xylooligosaccharides (XOS) production from commercial heteroxylans and liquor of hydrothermally pretreated corn cobs (PCC). PpXyn10A is tolerant to ethanol and NaCl, and releases xylobiose (X2) and xylotriose (X3) as the main hydrolytic products. The conversion rate of complex substrates into short XOS was approximately 30% for glucuronoxylan and 8.8% for rye arabinoxylan, after only 4 h; while for PCC, PpXyn10A greatly increased unbranched XOS yields. B. adolescentis fermentation with XOS from beechwood glucuronoxylan produced mainly acetic and lactic acids. Structural analysis shows that while the glycone region of PpXyn10A active site is well preserved, the aglycone region has aromatic interactions in the +2 subsite that may explain why PpXyn10A does not release xylose.


Asunto(s)
Bacteroidetes , Endo-1,4-beta Xilanasas/metabolismo , Glucuronatos/química , Oligosacáridos/química , Xilanos/química , Animales , Bifidobacterium adolescentis/efectos de los fármacos , Disacáridos/química , Fermentación , Glucuronatos/farmacología , Humanos , Hidrólisis , Oligosacáridos/farmacología , Prebióticos , Trisacáridos/química , Xilosa/química , Zea mays/química
19.
Molecules ; 26(19)2021 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-34641431

RESUMEN

Blood group antigenic A trisaccharide represents the terminal residue of all A blood group antigens and plays a key role in blood cell recognition and blood group compatibility. Herein, we describe the synthesis of the spacered A trisaccharide by means of an assembly scheme that employs in its most complex step the recently proposed glycosyl donor of the 2-azido-2-deoxy-selenogalactoside type, bearing stereocontrolling 3-O-benzoyl and 4,6-O-(di-tert-butylsilylene)-protecting groups. Its application provided efficient and stereoselective formation of the required α-glycosylation product, which was then deprotected and subjected to spacer biotinylation to give both target products, which are in demand for biochemical studies.


Asunto(s)
Antígenos de Grupos Sanguíneos/biosíntesis , Trisacáridos/química , Biotinilación , Glicosilación , Humanos
20.
Int J Mol Sci ; 22(18)2021 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-34576050

RESUMEN

Intracerebral hemorrhage (ICH) occurs when brain blood vessels rupture, causing inflammation and cell death. 2-Fucosyllactose (2FL), a human milk oligosaccharide, has potent antiapoptotic and anti-inflammatory effects. The purpose of this study was to examine the protective effect of 2FL in cellular and rodent models of ICH. Hemin was added to a primary rat cortical neuronal and BV2 microglia coculture to simulate ICH in vitro. IBA1 and MAP2 immunoreactivities were used to determine inflammation and neuronal survival. Hemin significantly increased IBA1, while it reduced MAP2 immunoreactivity. 2FL significantly antagonized both responses. The protective effect of 2FL was next examined in a rat ICH model. Intracerebral administration of type VII collagenase reduced open-field locomotor activity. Early post-treatment with 2FL significantly improved locomotor activity. Brain tissues were collected for immunohistochemistry and qRT-PCR analysis. 2FL reduced IBA1 and CD4 immunoreactivity in the lesioned striatum. 2FL downregulated the expression of ER stress markers (PERK and CHOP), while it upregulated M2 macrophage markers (CD206 and TGFß) in the lesioned brain. Taken together, our data support that 2FL has a neuroprotective effect against ICH through the inhibition of neuroinflammation and ER stress. 2FL may have clinical implications for the treatment of ICH.


Asunto(s)
Proteínas de Unión al Calcio/genética , Accidente Cerebrovascular Hemorrágico/tratamiento farmacológico , Proteínas de Microfilamentos/genética , Proteínas Asociadas a Microtúbulos/genética , Trisacáridos/farmacología , Animales , Línea Celular , Técnicas de Cocultivo , Colagenasas/toxicidad , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Hemina/toxicidad , Accidente Cerebrovascular Hemorrágico/inducido químicamente , Accidente Cerebrovascular Hemorrágico/genética , Accidente Cerebrovascular Hemorrágico/patología , Humanos , Locomoción/efectos de los fármacos , Microglía/efectos de los fármacos , Microglía/patología , Leche Humana/química , Neuronas/efectos de los fármacos , Neuronas/patología , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/farmacología , Oligosacáridos/química , Oligosacáridos/farmacología , Ratas , Trisacáridos/química
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