Molecular determinants of Neu5Ac binding to a tripartite ATP independent periplasmic (TRAP) transporter

eLife, Journal Year: 2025, Volume and Issue: 13

Published: Feb. 6, 2025

N -Acetylneuraminic acid (Neu5Ac) is a negatively charged nine-carbon amino sugar that often the peripheral in human cell-surface glycoconjugates. Some bacteria scavenge, import, and metabolize Neu5Ac or redeploy it on their cell surfaces for immune evasion. The import of by many mediated tripartite ATP-independent periplasmic (TRAP) transporters. We have previously reported structures SiaQM, membrane-embedded component Haemophilus influenzae TRAP transport system, (Currie et al., 2024). However, none published contain bound to SiaQM. This information critical defining mechanism further structure-activity relationship studies. Here, we report Fusobacterium nucleatum SiaQM with without Neu5Ac. Both are an inward (cytoplasmic side) facing conformation. Neu5Ac-bound structure reveals interactions transporter its Na + binding sites. Two -binding sites similar those described previously. identify third metal-binding site away buried elevator domain. Ser300 Ser345 interact C1-carboxylate group Proteoliposome-based assays showed Ser300-Neu5Ac interaction transport, whereas dispensable. primarily interacts residues domain protein, thereby supporting operator mechanism. interacting conserved, providing fundamental required design inhibitors against this class proteins.

Language: Английский

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CRISPR-Cas-based identification of a sialylated human milk oligosaccharides utilization cluster in the infant gut commensal Bacteroides dorei

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Jan. 2, 2024

Abstract The infant gut microbiome is impacted by early-life feeding, as human milk oligosaccharides (HMOs) found in breastmilk cannot be digested infants and serve nutrients for their bacteria. While the vast majority of HMO-utilization research has focused on Bifidobacterium species, recent studies have suggested additional HMO-utilizers, mostly Bacteroides , yet utilization mechanism poorly characterized. Here, we investigate dorei isolates from breastfed-infants identify that polysaccharide locus (PUL) 33 enables B. to utilize sialylated HMOs. We perform transcriptional profiling identity upregulated genes when growing Using CRISPR-Cas12 knock-out four PUL33 genes, combined with complementation assays, GH33 critical gene HMO-utilization. This demonstration an system species isolated opens way further characterization such systems, better understand gut.

Language: Английский

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Ovomucin Hydrolysates Reduce Bacterial Adhesion and Inflammation in Enterotoxigenic Escherichia coli (ETEC) K88-Challenged Intestinal Epithelial Cells

Journal of Agricultural and Food Chemistry, Journal Year: 2024, Volume and Issue: 72(13), P. 7219 - 7229

Published: March 20, 2024

Enterotoxigenic Escherichia coli (ETEC) K88 is the most common cause of diarrhea in neonatal and postweaning pigs. After adhering to small intestinal epithelial cells via glycoprotein receptor recognition, pathogen can produce enterotoxins, impair integrity, trigger watery diarrhea, induce inflammation nuclear factor κB (NF-κB) mitogen-activated protein kinase phosphatase (MAPK) pathways. Inhibiting ETEC adhesion cell surfaces by interfering with receptor-fimbriae recognition provides a promising strategy prevent initiation progression infection. Ovomucin highly glycosylated chicken egg white diverse bioactivities. hydrolysates prepared enzymes Protex 26L (OP) pepsin/pancreatin (OPP) were previously revealed IPEC-J2 cells. Herein, we investigated protective effects ovomucin on K88-induced barrier integrity damage Caco-2 Both inhibited protected restoring transepithelial electronic resistance (TEER) values. Removing sialic acids reduced their antiadhesive capacities. suppressed ETEC-induced activation NF-κB MAPK signaling pathways both lines. The ability activating calcium/calmodulin-dependent 2 (CaMK II), elevating intracellular Ca2+ concentration, inducing oxidative stress was attenuated hydrolysates. In conclusion, this study demonstrated potential alleviate

Language: Английский

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Molecular determinants of Neu5Ac binding to a tripartite ATP independent periplasmic (TRAP) transporter

Published: Jan. 23, 2025

N -Acetylneuraminic acid (Neu5Ac) is a negatively charged nine-carbon amino-sugar that often the peripheral sugar in human cell-surface glycoconjugates. Some bacteria scavenge, import, and metabolize Neu5Ac or redeploy it on their cell surfaces for immune evasion. The import of by many mediated tripartite ATP-independent periplasmic (TRAP) transporters. We have previously reported structures SiaQM, membrane-embedded component Haemophilus influenzae TRAP transport system, (Currie et al., 2024). However, none published contain bound to SiaQM. This information critical defining mechanism further structure-activity relationship studies. Here, we report Fusobacterium nucleatum SiaQM with without Neu5Ac. Both are an inward (cytoplasmic side) facing conformation. Neu5Ac-bound structure reveals interactions transporter its Na + binding sites. Two -binding sites similar those described previously. identify third metal-binding site away buried elevator domain. Ser300 Ser345 interact C1-carboxylate group Proteoliposome-based assays showed Ser300-Neu5Ac interaction transport, whereas dispensable. primarily interacts residues domain protein, thereby supporting operator mechanism. interacting conserved, providing fundamental required design inhibitors against this class proteins.

Language: Английский

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Sialic Acids in Health and Disease

Biologics, Journal Year: 2025, Volume and Issue: 5(2), P. 10 - 10

Published: March 26, 2025

Vertebrate cell surfaces exhibit intricate arrangements of glycosaminoglycan polymers, which are primarily linked to lipids and proteins. Numerous soluble secreted proteins also decorated with either individual sugar molecules or their polymers. The carbohydrate polymers commonly possess terminal nine-carbon sugars, known as sialic acids. Due widespread distribution strategic positioning, acids play a crucial role in mediating regulating wide range physiologic processes pathologic conditions. Human- animal-based investigations predominantly concentrate on the effects during infections, inflammations, vascular disorders, cancers. Further encompass variety applications, including cell–cell interactions, signaling, host–pathogen other biological functions associated nutrition, metabolism, genetic disorders. Nevertheless, future mechanistic needed clarify specific roles these varied contexts, so that more effective interventions may be developed.

Language: Английский

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The role of glycosylated mucins in maintaining intestinal homeostasis and gut health

Animal nutrition, Journal Year: 2025, Volume and Issue: unknown

Published: April 1, 2025

Language: Английский

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Enhancing the persistence of engineered biotherapeutics in the gut: Adhesion, glycan metabolism, and environmental resistance

Advanced Drug Delivery Reviews, Journal Year: 2025, Volume and Issue: unknown, P. 115591 - 115591

Published: April 1, 2025

Language: Английский

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Gellan gum-sialoglycan conjugates: a mucin mimic for alleviating inflammation in Caco-2 cells and modulating gut microbiota in the elderly

International Journal of Biological Macromolecules, Journal Year: 2025, Volume and Issue: 310, P. 143478 - 143478

Published: April 24, 2025

Language: Английский

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Cross-feeding between beneficial and pathogenic bacteria to utilize eukaryotic host cell-derived sialic acids and bacteriophages shape the pathogen-host interface milieu

Experimental and Molecular Pathology, Journal Year: 2025, Volume and Issue: 142, P. 104967 - 104967

Published: April 25, 2025

Under an inflamed-intestinal milieu, increased free sialic acids are associated with the overgrowth of some pathogenic bacterial strains. Recently, protective immunomodulatory activity gut bacteriophages (phages) has also been highlighted. However, role phages in triple reciprocal interactions between bacteria, beneficial and their host cell not studied so far. We established a sialidase-explicit model which bacteria interact through cross-feeding competition for acid using human co-culture incorporating colonocytes (T84 cells), monocytes (THP-1 hepatocytes (Huh7 cells). Triple co-cultured cells were challenged Gram-positive Bifidobacterium bifidum (B. bifidum) Gram-negative Pseudomonas aeruginosa PAO1 (P. PAO1) absence or presence its KPP22 phage two different culture mediums: 1) standard Dulbecco's Modified Eagle Medium (DMEM) 2) DMEM 2,3-dehydro-2-deoxy-N-acetylneuraminic (DANA). Changes physiological, functional, structural health markers stimulated cocultured evaluated. The concentrations pro-inflammatory cytokines supernatants quantified. P. triggered release interleukin 6 8 (IL-6 IL-8), accompanied by levels acid, reduced viability cells, disrupted integrity cellular monolayer. These disruptive effects markedly attenuated B. bifidum. In addition to well-documented differences structure composition walls bifidobacteria, distinct factors seem be pivotal modulating pathogen-host interface milieu: (i) (ii) utilization secreted from bifidobacteria.

Language: Английский

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Insights into the Structure, Metabolism, Biological Functions and Molecular Mechanisms of Sialic Acid: A Review

Foods, Journal Year: 2023, Volume and Issue: 13(1), P. 145 - 145

Published: Dec. 31, 2023

Sialic acid (SA) is a kind of functional monosaccharide which exists widely in edible bird’s nest (EBN), milk, meat, mucous membrane surface, etc. SA an important component promoting brain development, anti-oxidation, anti-inflammation, anti-virus, anti-tumor and immune regulation. The intestinal mucosa covers the microbial community that has significant impact on health. In gut, can also regulate gut microbiota metabolites, participating different biological functions. structure, source physiological functions were reviewed this paper. through regulating key signaling pathways target genes discussed. summary, modulate affect gene expressions exert its activities. It helpful to provide scientific reference for further investigation foods.

Language: Английский

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