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1.
Nat Commun ; 12(1): 44, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33398001

RESUMO

In Bacteroidetes, one of the dominant phyla of the mammalian gut, active uptake of large nutrients across the outer membrane is mediated by SusCD protein complexes via a "pedal bin" transport mechanism. However, many features of SusCD function in glycan uptake remain unclear, including ligand binding, the role of the SusD lid and the size limit for substrate transport. Here we characterise the ß2,6 fructo-oligosaccharide (FOS) importing SusCD from Bacteroides thetaiotaomicron (Bt1762-Bt1763) to shed light on SusCD function. Co-crystal structures reveal residues involved in glycan recognition and suggest that the large binding cavity can accommodate several substrate molecules, each up to ~2.5 kDa in size, a finding supported by native mass spectrometry and isothermal titration calorimetry. Mutational studies in vivo provide functional insights into the key structural features of the SusCD apparatus and cryo-EM of the intact dimeric SusCD complex reveals several distinct states of the transporter, directly visualising the dynamics of the pedal bin transport mechanism.


Assuntos
Proteínas de Bactérias/metabolismo , Microbioma Gastrointestinal , Polissacarídeos/metabolismo , Simbiose , Proteínas de Bactérias/química , Microscopia Crioeletrônica , Ligantes , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Oligossacarídeos/química , Polissacarídeos/química , Conformação Proteica , Relação Estrutura-Atividade
2.
Food Chem ; 340: 128208, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33022558

RESUMO

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


Assuntos
Cerveja/análise , Análise de Alimentos/métodos , Oligossacarídeos/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Limite de Detecção , Oligossacarídeos/química , Reprodutibilidade dos Testes , Fatores de Tempo
3.
Food Chem ; 339: 128027, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32949915

RESUMO

κ-Carrageenase cleaves the ß-(1-4) linkages of κ-carrageenan into κ-carrageenan oligosaccharides (κ-COS), which exhibit various biological activities. In this study, a glycoside hydrolase (GH) family 16 κ-carrageenase gene, cgkA, was cloned from the marine bacterium Vibrio sp. SY01 and secretory expressed in a food-grade host, Yarrowia lipolytica. The specific activity of the purified CgkA was 12.5 U/mg. Determination of biochemical properties showed that CgkA was a thermo-tolerant enzyme, and 59.9% of the initial enzyme activity was recovered by immediately placing the sample at 20 °C for 30 min after enzymatic inactivation by boiling for 5 min. The recombinant CgkA was an endo-type enzyme, the main enzymatic product was κ-carradiaose (accounting for 87.6% of total products), and κ-carratetraose was the minimum substrate. Additionally, in vitro and in vivo analyses indicated that enzymatic κ-carradiaose possesses anti-oxidant activity. These features make CgkA as a promising candidate for biotechnological applications in the production of anti-oxidant κ-COS.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Proteínas de Bactérias/metabolismo , Glicosídeo Hidrolases/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Células CACO-2 , Carragenina/química , Carragenina/metabolismo , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Humanos , Hidrólise , Simulação de Acoplamento Molecular , Oligossacarídeos/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Vibrio/genética , Yarrowia/genética
4.
Food Chem ; 334: 127428, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32688173

RESUMO

Aspergillus quadrilineatus endo-ß-mannanase effectively degraded konjac glucomannan (66.09% w/v), copra meal (38.99% w/v) and locust bean galactomannan (20.94% w/v). High performance liquid chromatography (HPLC) analysis of KG hydrolysate indicated its mannooligosaccharides (MOS) content (656.38 mg/g) with high amounts of DP 5 oligosaccharide. Multi-scale characterization of mannan hydrolysate was done using FTIR and 13C NMR which revealed α and ß form of galactose or glucose in MOS, respectively. CM and LBG hydrolysates (1 mg/mL) have shown cytotoxic effect and reduced cell viability of Caco-2 cells by 45% and 62%, respectively. MOS DP (1-4) derived from LBG supported better Lactobacilli biofilm formation as compared to KG hydrolysate containing high DP MOS (5-7). Lactobacilli effectively fermented MOS to generate acetate and propionate as main short chain fatty acids. Lactobacilli produced leucine, isoleucine and valine as branched chain amino acids when grown on LBG hydrolysate.


Assuntos
Mananas/química , Oligossacarídeos/farmacologia , Prebióticos , beta-Manosidase/metabolismo , Aspergillus/enzimologia , Biofilmes , Células CACO-2 , Fermentação , Humanos , Hidrólise , Lactobacillus/crescimento & desenvolvimento , Espectroscopia de Ressonância Magnética , Mananas/metabolismo , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , beta-Manosidase/química
5.
Food Chem ; 337: 127992, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920270

RESUMO

Mechanical wounding causes significant economic losses of fresh produce due to accelerated senescence and spoilage as well as loss of nutritional value. Here, pre-application of oligogalacturonides (OGs) enzymatically hydrolyzed from apple pectin effectively reduced the healing times of mechanical wounds from>24 h in mock groups to 12 h, and the Botrytis cinerea infection rate was reduced from 37.5% to 12.5%. OGs accordingly increased callose deposition; SlPR1, SlPAL and SlHCT gene expression; and phenylalanine ammonia-lyase (PAL) activity around the wounds. Inhibition of Ca2+ signaling using the inhibitor Ruthenium Red markedly inhibited OG accelerated healing of mechanical wounding on fruit. SlPG2, SlEXP1, and SlCEL2 mRNAs accumulation was reduced in OG-elicited tomato fruit compared to water-treated fruit with subsequent retardation of the fruit softening during ripening. These results indicated that apple pectin OGs accelerate wound healing and inhibit fruit softening by activating calcium signaling in tomato fruits during postharvest storage.


Assuntos
Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/fisiologia , Oligossacarídeos/farmacologia , Botrytis/patogenicidade , Cálcio/metabolismo , Frutas/efeitos dos fármacos , Frutas/metabolismo , Frutas/microbiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glucanos/metabolismo , Hidrólise , Lycopersicon esculentum/microbiologia , Malus/química , Oligossacarídeos/química , Pectinas/química , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Food Chem ; 341(Pt 1): 128178, 2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33022576

RESUMO

Lack of proper postharvest management of fruits causes huge economic loss, increase poverty, hunger and malnutrition. To reduce postharvest losses, globally different postharvest technologies and synthetic chemical treatments were widely used, but some of them are reported to enhance the risk for human health and environment. Recently, oligosaccharides have attractedmuch attention because of their numerous health benefits, and potential applications in agriculture. Many previous reports demonstrated that oligosaccharides treatment improves the postharvest preservation of fruits and extend the shelf life. Oligosaccharides postharvest treatments maintained higher non enzymatic antioxidant activity, increased antioxidant activity, regulate hormone biosynthesis and delayed cell wall degradation. In this review, we systematically summarize and discuss the recent research findings concerning the preservation effects of different oligosaccharides, and their mechanism underlying delaying ripening and senescence of fruits during postharvest storage. Moreover, we provide future research direction for the utilization of oligosaccharides to improve postharvest preservation of fruits.


Assuntos
Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Frutas , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Enzimas/metabolismo , Conservantes de Alimentos/química , Qualidade dos Alimentos , Armazenamento de Alimentos , Frutas/química , Frutas/fisiologia
7.
Biochim Biophys Acta Gen Subj ; 1865(1): 129765, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33069832

RESUMO

BACKGROUND: Heparin, a lifesaving blood thinner used in over 100 million surgical procedures worldwide annually, is currently isolated from over 700 million pigs and ~200 million cattle in slaughterhouses worldwide. Though animal-derived heparin has been in use over eight decades, it is a complex mixture that poses a risk for chemical adulteration, and its availability is highly vulnerable. Therefore, there is an urgent need in devising bioengineering approaches for the production of heparin polymers, especially low molecular weight heparin (LMWH), and thus, relying less on animal sources. One of the main challenges, however, is the rapid, cost-effective production of low molecular weight heparosan, a precursor of LMWH and size-defined heparosan oligosaccharides. Another challenge is N-sulfation of N-acetyl heparosan oligosaccharides efficiently, an essential modification required for subsequent enzymatic modifications, though chemical and enzymatic N-sulfation is effectively performed at the polymer level. METHODS: To devise a strategy to produce low molecular weight heparosan and heparosan oligosaccharides, several non-pathogenic E. coli strains are engineered by transforming the essential heparosan biosynthetic genes with or without the eliminase gene (elmA) from pathogenic E. coli K5. RESULTS: The metabolically engineered non-pathogenic strains are shown to produce ~5 kDa heparosan, a precursor for low molecular weight heparin, for the first time. Additionally, heparosan oligosaccharides of specific sizes ranging from tetrasaccharide to dodecasaccharide are directly generated, in a single step, from the recombinant bacterial strains that carry both heparosan biosynthetic genes and the eliminase gene. Various modifications, such as chemical N-sulfation of N-acetyl heparosan hexasaccharide following the selective protection of reducing end GlcNAc residue, enzymatic C5-epimerization of N-sulfo heparosan tetrasaccharide and complete 6-O sulfation of N-sulfo heparosan hexasaccharide, are shown to be feasible. CONCLUSIONS: We engineered non-pathogenic E. coli strains to produce low molecular weight heparosan and a range of size-specific heparosan oligosaccharides in a controlled manner through modulating culture conditions. We have also shown various chemical and enzymatic modifications of heparosan oligosaccharides. GENERAL SIGNIFICANCE: Heparosan is a precursor of heparin and the methods to produce low molecular weight heparosan is widely awaited. The methods described herein are promising and will pave the way for potential large scale production of low molecular weight heparin anticoagulants and bioactive heparin oligosaccharides in the coming decade.


Assuntos
Dissacarídeos/metabolismo , Escherichia coli/metabolismo , Engenharia Metabólica , Oligossacarídeos/metabolismo , Dissacarídeos/química , Dissacarídeos/genética , Escherichia coli/química , Escherichia coli/genética , Microbiologia Industrial , Oligossacarídeos/química , Oligossacarídeos/genética
8.
Int J Nanomedicine ; 15: 9373-9387, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33262593

RESUMO

Purpose: The trans-ocular barrier is a key factor limiting the therapeutic efficacy of triamcinolone acetonide. We developed a poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) surface modified respectively with 2-hydroxypropyl-ß-cyclodextrin (2-HP-ß-CD), chitosan oligosaccharide and trehalose. Determination of the drug/nanoparticles interactions, characterization of the nanoparticles, in vivo ocular compatibility tests, comparisons of their corneal permeability and their pharmacokinetics in aqueous humor were carried out. Methods: All PLGA NPs were prepared by the single emulsion and evaporation method and the drug-nanoparticle interaction was studied. The physiochemical features and in vitro corneal permeability of NPs were characterized while the aqueous humor pharmacokinetics was performed to evaluate in vivo corneal permeability of NPs. Ocular compatibility of NPs was investigated through Draize and histopathological test. Results: The PLGA NPs with lactide/glycolide ratio of 50:50 and small particle size (molecular weight 10 kDa) achieved optimal drug release and corneal permeability. Surface modification with different oligosaccharides resulted in uniform particle sizes and similar drug-nanoparticle interactions, although 2-HP-ß-CD/PLGA NPs showed the highest entrapment efficiency. In vitro evaluation and aqueous humor pharmacokinetics further revealed that 2-HP-ß-CD/PLGA NPs had greater trans-ocular permeation and retention compared to chitosan oligosaccharide/PLGA and trehalose/PLGA NPs. No ocular irritation in vivo was detected after applying modified/unmodified PLGA NPs to rabbit's eyes. Conclusion: 2-HP-ß-CD/PLGA NPs are a promising nanoplatform for localized ocular drug delivery through topical administration.


Assuntos
2-Hidroxipropil-beta-Ciclodextrina/química , Córnea/metabolismo , Portadores de Fármacos/química , Membranas Artificiais , Nanopartículas/química , Oligossacarídeos/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Animais , Liberação Controlada de Fármacos , Tamanho da Partícula , Permeabilidade , Coelhos
9.
PLoS One ; 15(11): e0240264, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33170861

RESUMO

This study investigated whether the inclusion of a stimbiotic (STB) can improve performance, influence intestinal microbiota and fermentation activity, and reduce pro-inflammatory cytokines in piglets fed a low zinc oxide diet without antimicrobial growth promotors compared to fructo-oligosaccharide (FOS) and mannan-oligosaccharide (MOS) when housed either in good sanitary (GS) or poor sanitary (PS) environments. One hundred forty-four male pigs (28-day-old) were sorted by initial body weight (BW) and allocated to one of six experimental treatments: 1) GS environment without any additive (GS-CTR); 2) GS environment with 0.01% stimbiotic (GS-STB); 3) PS environment (without cleaning and disinfection of a previously populated room) without any additive (PS-CTR); 4) PS environment with 0.01% STB (PS-STB); 5) PS environment with 0.1% MOS (PS-MOS); and 6) PS environment with 0.2% FOS (PS-FOS). Each treatment had six replicates, with four animals each. Three feeding phases, based on corn, wheat, and soybean meal were available ad libitum for the 42-days of the study. Housing piglets under PS conditions negatively influenced performance, increased plasma tumor necrosis factor alpha (TNF-α), affected the fecal microbial populations and increased concentrations of branched-chain fatty acids (BCFA) compared to GS. Stimbiotic improved 42-d-BW under PS conditions (P < 0.05) whereas MOS or FOS had no effect. On d35, plasma TNF-α was reduced with STB in PS (P < 0.05). The ratio between VFA:BCFA increased (P < 0.05) with STB, MOS or FOS in PS, and under GS condition, STB also increased the ratio. Stimbiotic increased the proportion of Clostridiales Family XIII Incertae Sedis and Clostridiaceae, while MOS and FOS increased Selenomonadaceae, Catabacteriaceae and Fibrobacteraceae. These results indicate that STB shifted the intestinal microbiome to favor fiber fermentation which likely contributed to reduced inflammatory response and improved performance, particularly in piglets reared in PS conditions.


Assuntos
Bactérias/classificação , Citocinas/metabolismo , Inflamação/dietoterapia , Oligossacarídeos/administração & dosagem , Óxido de Zinco/administração & dosagem , Animais , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Peso Corporal/efeitos dos fármacos , Fibras na Dieta , Suplementos Nutricionais , Endotoxinas/metabolismo , Fermentação , Regulação da Expressão Gênica/efeitos dos fármacos , Sequenciamento de Nucleotídeos em Larga Escala , Abrigo para Animais , Inflamação/metabolismo , Masculino , Mananas/química , Oligossacarídeos/química , Oligossacarídeos/farmacologia , RNA Ribossômico 16S/genética , Suínos , Desmame , Óxido de Zinco/farmacologia
10.
Nat Commun ; 11(1): 4874, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978395

RESUMO

Organic synthesis methodology enables the synthesis of complex molecules and materials used in all fields of science and technology and represents a vast body of accumulated knowledge optimally suited for deep learning. While most organic reactions involve distinct functional groups and can readily be learned by deep learning models and chemists alike, regio- and stereoselective transformations are more challenging because their outcome also depends on functional group surroundings. Here, we challenge the Molecular Transformer model to predict reactions on carbohydrates where regio- and stereoselectivity are notoriously difficult to predict. We show that transfer learning of the general patent reaction model with a small set of carbohydrate reactions produces a specialized model returning predictions for carbohydrate reactions with remarkable accuracy. We validate these predictions experimentally with the synthesis of a lipid-linked oligosaccharide involving regioselective protections and stereoselective glycosylations. The transfer learning approach should be applicable to any reaction class of interest.


Assuntos
Carboidratos/química , Aprendizado de Máquina , Oligossacarídeos/química , Metabolismo dos Carboidratos , Técnicas de Química Sintética , Glicosilação , Estrutura Molecular , Oligossacarídeos/metabolismo
11.
Int J Biol Macromol ; 163: 1649-1658, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32979436

RESUMO

The SARS-CoV-2 spike glycoproteins (SGPs) and human angiotensin converting enzyme 2 (ACE2) are the two key targets for the prevention and treatment of COVID-19. Host cell surface heparan sulfate (HS) is believed to interact with SARS-CoV-2 SGPs to facilitate host cell entry. In the current study, a series of polysaccharides from Saccharina japonica were prepared to investigate the structure-activity relationship on the binding abilities of polysaccharides (oligosaccharides) to pseudotype particles, including SARS-CoV-2 SGPs, and ACE2 using surface plasmon resonance. Sulfated galactofucan (SJ-D-S-H) and glucuronomannan (Gn) displayed strongly inhibited interaction between SARS-CoV-2 SGPs and heparin while showing negligible inhibition of the interaction between SARS-CoV-2 SGPs and ACE2. The IC50 values of SJ-D-S-H and Gn in blocking heparin SGP binding were 27 and 231 nM, respectively. NMR analysis showed that the structure of SJ-D-S-H featured with a backbone of 1, 3-linked α-L-Fucp residues sulfated at C4 and C2/C4 and 1, 3-linked α-L-Fucp residues sulfated at C4 and branched with 1, 6-linked ß-D-galacto-biose; Gn had a backbone of alternating 1, 4-linked ß-D-GlcAp residues and 1, 2-linked α-D-Manp residues. The sulfated galactofucan and glucuronomannan showed strong binding ability to SARS-CoV-2 SGPs, suggesting that these polysaccharides might be good candidates for preventing and/or treating SARS-CoV-2.


Assuntos
Infecções por Coronavirus/virologia , Glucuronatos/metabolismo , Manose/análogos & derivados , Pneumonia Viral/virologia , Polissacarídeos/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Betacoronavirus/química , Betacoronavirus/metabolismo , Sítios de Ligação , Glucuronatos/química , Heparina/química , Heparina/metabolismo , Humanos , Manose/química , Manose/metabolismo , Oligossacarídeos/química , Pandemias , Peptidil Dipeptidase A/metabolismo , Feófitas/química , Polissacarídeos/química , Ligação Proteica , Glicoproteína da Espícula de Coronavírus/química , Relação Estrutura-Atividade
12.
Nat Commun ; 11(1): 3963, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32770134

RESUMO

Polysaccharides are the most abundant biomolecules in nature, but are the least understood in terms of their chemical structures and biological functions. Polysaccharides cannot be simply sequenced because they are often highly branched and lack a uniform structure. Furthermore, large polymeric structures cannot be directly analyzed by mass spectrometry techniques, a problem that has been solved for polynucleotides and proteins. While restriction enzymes have advanced genomic analysis, and trypsin has advanced proteomic analysis, there has been no equivalent enzyme for universal polysaccharide digestion. We describe the development and application of a chemical method for producing oligosaccharides from polysaccharides. The released oligosaccharides are characterized by advanced liquid chromatography-mass spectrometry (LC-MS) methods with high sensitivity, accuracy and throughput. The technique is first used to identify polysaccharides by oligosaccharide fingerprinting. Next, the polysaccharide compositions of food and feces are determined, further illustrating the utility of technique in food and clinical studies.


Assuntos
Oligossacarídeos/química , Polissacarídeos/metabolismo , Bactérias/metabolismo , Glucanos/química , Glucanos/metabolismo , Humanos , Lactente , Mananas/química , Mananas/metabolismo , Oxirredução , Polimerização , Fatores de Tempo , Xilanos/química , Xilanos/metabolismo
13.
J Chromatogr A ; 1625: 461331, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709357

RESUMO

In this work, a novel imidazolium bonding method was proposed for the synthesis of hydrophilic interaction liquid chromatography (HILIC) stationary phases. One obtained stationary phase (SilprAprImCl) was derived from direct reaction between N-(3-aminopropyl)-imidazole and 3-chloropropylated silica gel. Other two materials (SilprAprImBF4 and SilprAprImTf2N) were obtained from SilprAprImCl by ion exchange reaction, respectively. Fourier-transform infrared spectroscopy and elemental analysis afforded the proofs of successful imidazolium immobilization and satisfied bonding efficiency. Various polar compounds such as saccharides, nucleosides, and nucleobases were utilized to evaluate the retention behaviours of these materials in HILIC mode. Different effects from mobile composition, column temperature, imidazolium unite and paired anions (Cl-, BF4-, and Tf2N-) in imidazolium were proved and discussed. Separation mechanism and the role of the imidazolium ions were also investigated in mobile phases with different pH. Moreover, chromatographic stability was evaluated by consecutive injections. Finally, the reliability of these stationary phases was demonstrated by the separation of oligosaccharides in real fructooligosaccharides samples.


Assuntos
Cromatografia Líquida/métodos , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/química , Propanóis/química , Ânions , Concentração de Íons de Hidrogênio , Imidazóis/síntese química , Líquidos Iônicos/química , Nucleosídeos/química , Nucleosídeos/isolamento & purificação , Oligossacarídeos/química , Propanóis/síntese química , Reprodutibilidade dos Testes , Temperatura
14.
J Biosci Bioeng ; 130(5): 443-449, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32727668

RESUMO

Mannooligosaccharides (MOSs) are one of the most commonly used biomass-derived feed additives. The effectiveness of MOS varies with the length of oligosaccharides, medium length MOSs such as mannotetraose and mannopentaose being the most efficient. This study aims at improving specificity of ß-mannanase from Aspergillus niger toward the desirable product size through rational-based enzyme engineering. Tyr 42 and Tyr 132 were mutated to Gly to extend the substrate binding site, allowing higher molecular weight MOS to non-catalytically bind to the enzyme. Hydrolysis product content was analyzed by high-performance anion-exchange chromatography with pulsed amperometric detection. Instead of mannobiose, the enzyme variants yielded mannotriose and mannotetraose as the major products, followed by mannobiose and mannopentaose. Overall, 42% improvement in production yield of highly active mannotetraose and mannopentaose was achieved. This validates the use of engineered ß-mannanase to selectively produce larger MOS, making them promising candidates for large-scale MOS enzymatic production process.


Assuntos
Aspergillus niger/enzimologia , Manose/química , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Engenharia de Proteínas , beta-Manosidase/genética , beta-Manosidase/metabolismo , Aspergillus niger/genética , Hidrólise , Especificidade por Substrato
15.
Int J Nanomedicine ; 15: 4021-4047, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606662

RESUMO

Purpose: Periodontitis is a chronic inflammatory disease associated with microbial accumulation. The purpose of this study was to reuse the agricultural waste to produce cellulose nanofibers (CNF) and further modification of the CNF with κ-carrageenan oligosaccharides (CO) for drug delivery. In addition, this study is focused on the antimicrobial activity of surfactin-loaded CO-CNF towards periodontal pathogens. Materials and Methods: A chemo-mechanical method was used to extract the CNF and the modification was done by using CO. The studies were further proceeded by adding different quantities of surfactin [50 mg (50 SNPs), 100 mg (100 SNPs), 200 mg (200 SNPs)] into the carrier (CO-CNF). The obtained materials were characterized, and the antimicrobial activity of surfactin-loaded CO-CNF was evaluated. Results: The obtained average size of CNF and CO-CNF after ultrasonication was 263 nm and 330 nm, respectively. Microscopic studies suggested that the CNF has a short diameter with long length and CO became cross-linked to form as beads within the CNF network. The addition of CO improved the degradation temperature, crystallinity, and swelling property of CNF. The material has a controlled drug release, and the entrapment efficiency and loading capacity of the drug were 53.15 ± 2.36% and 36.72 ± 1.24%, respectively. It has antioxidant activity and inhibited the growth of periodontal pathogens such as Streptococcus mutans and Porphyromonas gingivalis by preventing the biofilm formation, reducing the metabolic activity, and promoting the oxidative stress. Conclusion: The study showed the successful extraction of CNF and modification with CO improved the physical parameters of the CNF. In addition, surfactin-loaded CO-CNF has potential antimicrobial activity against periodontal pathogens. The obtained biomaterial is economically valuable and has great potential for biomedical applications.


Assuntos
Carragenina/química , Celulose/química , Lipopeptídeos/química , Nanofibras/química , Peptídeos Cíclicos/química , Periodonto/microbiologia , Animais , Bactérias/metabolismo , Compostos de Bifenilo/química , Sobrevivência Celular , Difusão Dinâmica da Luz , Depuradores de Radicais Livres/química , Malondialdeído/metabolismo , Camundongos , Testes de Sensibilidade Microbiana , Nanofibras/ultraestrutura , Oligossacarídeos/química , Picratos/química , Células RAW 264.7 , Soja/química , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Nat Metab ; 2(8): 678-687, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32694823

RESUMO

Poor maternal environments, such as under- or overnutrition, can increase the risk for the development of obesity, type 2 diabetes and cardiovascular disease in offspring1-9. Recent studies in animal models have shown that maternal exercise before and during pregnancy abolishes the age-related development of impaired glucose metabolism10-15, decreased cardiovascular function16 and increased adiposity11,15; however, the underlying mechanisms for maternal exercise to improve offspring's health have not been identified. In the present study, we identify an exercise-induced increase in the oligosaccharide 3'-sialyllactose (3'-SL) in milk in humans and mice, and show that the beneficial effects of maternal exercise on mouse offspring's metabolic health and cardiac function are mediated by 3'-SL. In global 3'-SL knockout mice (3'-SL-/-), maternal exercise training failed to improve offspring metabolic health or cardiac function in mice. There was no beneficial effect of maternal exercise on wild-type offspring who consumed milk from exercise-trained 3'-SL-/- dams, whereas supplementing 3'-SL during lactation to wild-type mice improved metabolic health and cardiac function in offspring during adulthood. Importantly, supplementation of 3'-SL negated the detrimental effects of a high-fat diet on body composition and metabolism. The present study reveals a critical role for the oligosaccharide 3'-SL in milk to mediate the effects of maternal exercise on offspring's health. 3'-SL supplementation is a potential therapeutic approach to combat the development of obesity, type 2 diabetes and cardiovascular disease.


Assuntos
Nível de Saúde , Coração/fisiologia , Leite/química , Oligossacarídeos/metabolismo , Condicionamento Físico Animal/fisiologia , Adulto , Animais , Composição Corporal , Dieta Hiperlipídica/efeitos adversos , Exercício Físico/fisiologia , Feminino , Regulação da Expressão Gênica/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Leite Humano/química , Miocárdio/metabolismo , Oligossacarídeos/análise , Oligossacarídeos/química , Oligossacarídeos/genética
17.
Sci Rep ; 10(1): 10011, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32561796

RESUMO

Chitosan oligosaccharide functionalized silver nanoparticles with synergistic bacterial activity were constructed as a multivalent inhibitor of bacteria. Placing the chitosan oligosaccharide on silver nanoparticles can dramatically enhance the adsorption to the bacterial membrane via multivalent binding. The multicomponent nanostructures can cooperate synergistically against gram-positive and gram-negative bacteria. The antibacterial activity was increased via orthogonal array design to optimize the synthesis condition. The synergistic bacterial activity was confirmed by fractional inhibitory concentration and zone of inhibition test. Through studies of antimicrobial action mechanism, it was found that the nanocomposites interacted with the bacteria by binding to Mg2+ ions of the bacterial surface. Then, the nanocomposites disrupted bacterial membrane by increasing the permeability of the outer membrane, resulting in leakage of cytoplasm. This strategy of chitosan oligosaccharide modification can increase the antibacterial activity of silver nanoparticles and accelerate wound healing at the same time. The nanomaterial without cytotoxicity has promising applications in bacteria-infected wound healing therapy.


Assuntos
Antibacterianos/farmacologia , Infecções Bacterianas/tratamento farmacológico , Quitosana/farmacologia , Escherichia coli/efeitos dos fármacos , Nanocompostos/uso terapêutico , Oligossacarídeos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/uso terapêutico , Quitosana/química , Quitosana/uso terapêutico , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Nanocompostos/química , Oligossacarídeos/química , Oligossacarídeos/uso terapêutico , Prata/química
18.
Phys Chem Chem Phys ; 22(26): 14454-14457, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32597425

RESUMO

MA'AT conformational models of the phi torsion angles of O-glycosidic linkages differ from those obtained from MD simulation. To determine the source of the discrepancy, MA'AT analyses were performed using DFT-derived equations obtained with and without psi constraints. The resulting phi models were essentially the same, indicating a force-field problem. Circular standard deviations (CSDs) were found to provide reliable estimates of torsional averaging.


Assuntos
Oligossacarídeos/química , Configuração de Carboidratos , Simulação de Dinâmica Molecular
19.
Food Chem ; 329: 127179, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32505987

RESUMO

The prebiotic activities of hydrolyzed guar gum (GMOS, <1 kDa; GMPS, 1-10 kDa), manno-oligosaccharide (MOS, <1 kDa), and galacto-oligosaccharide (GOS, <1 kDa) were evaluated by in vitro fermentation. The tested carbohydrates showed selective prebiotic effects on bacterial growth, short-chain fatty acid (SCFA)-production, and substrate consumption. GOS and GMOS markedly promoted the growth of bifidobacteria and Clostridium butyricum, respectively, whereas MOS showed the strongest butyrogenic effect. Moreover, SCFA production in the hydrolyzed guar gum groups was closely related to the varied molecular weight (Mw) of the hydrolysate. During in vitro fermentation with human fecal inocula, GMOS gave the highest yields of lactate, propionate, and butyrate after 48 h fermentation. Combined application of MOS and C. butyricum increased the abundance of Clostridiaceae_1. Overall, our results indicate that galactosyl and mannosyl carbohydrates have individualized prebiotic effects which are associated with their chemical structures including their glycoside composition and Mw.


Assuntos
Oligossacarídeos/análise , Prebióticos/análise , Técnicas de Cultura Celular por Lotes , Bifidobacterium/efeitos dos fármacos , Bifidobacterium/genética , Bifidobacterium/crescimento & desenvolvimento , Cromatografia Líquida de Alta Pressão , Clostridium butyricum/efeitos dos fármacos , Clostridium butyricum/genética , Clostridium butyricum/crescimento & desenvolvimento , Ácidos Graxos Voláteis/química , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Galactanos/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Mananas/metabolismo , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Gomas Vegetais/metabolismo , RNA Ribossômico 16S/química , RNA Ribossômico 16S/metabolismo
20.
Chemistry ; 26(51): 11814-11818, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32515841

RESUMO

Heparin binds to and activates antithrombin (AT) through a specific pentasaccharide sequence, in which a trisaccharide subsite, containing glucuronic acid (GlcA), has been considered as the initiator in the recognition of the polysaccharide by the protein. Recently it was suggested that sulfated iduronic acid (IdoA2S) could replace this "canonical" GlcA. Indeed, a heparin octasaccharidic sequence obtained by chemoenzymatic synthesis, in which GlcA is replaced with IdoA2S, has been found to similarly bind to and activate antithrombin. By using saturation-transfer-difference (STD) NMR, NOEs, transferred NOEs (tr-NOEs) NMR and molecular dynamics, we show that, upon binding to AT, this IdoA2S unit develops comparable interactions with AT as GlcA. Interestingly, two IdoA2S units, both present in a 1 C4 -2 S0 equilibrium in the unbound saccharide, shift to full 2 S0 and full 1 C4 upon binding to antithrombin, providing the best illustration of the critical role of iduronic acid conformational flexibility in biological systems.


Assuntos
Anticoagulantes/química , Antitrombinas/química , Ácido Glucurônico/química , Heparina/química , Ácido Idurônico/química , Oligossacarídeos/química , Polissacarídeos/química , Anticoagulantes/farmacologia , Antitrombinas/metabolismo , Espectroscopia de Ressonância Magnética , Conformação Molecular , Sulfatos/química
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