Search Results (54)

Prebiotics are predominantly indigestible carbohydrate-based substrates selectively-utilized by beneficial gut-microbes to support host-health. We previously developed protein-containing prebiotics that co-deliver carbohydrate and protein substrates to the colon, where gut-microbes compete for the limited nitrogen availability, thereby enhancing microbial growth, metabolic activity, and host health compared with conventional carbohydrate prebiotics. Resveratrol is a grape-derived polyphenol with antioxidant, anti-inflammatory, and emerging prebiotic activity. Here, we developed a multifunctional protein-containing prebiotic system based on Maillard conjugates of 2′-fucosyllactose–potato protein hydrolysate (2′-FL-PPH) micelles encapsulating resveratrol, followed by genipin crosslinking. This crosslinked 2′-FL-PPH-resveratrol system is designed to limit premature protein and resveratrol absorption, enhancing their colonic co-delivery. We characterized the encapsulation efficacy, physicochemical properties, digestibility and colonic delivery. The conjugates (10 mg/mL 2′-FL-PPH) effectively entrapped resveratrol (600 µM), exhibiting an average particle size of ~28 nm and an encapsulation efficiency of 79.5 ± 4.9%. Binding studies demonstrated predominantly hydrophobic interactions between resveratrol and 2′-FL-PPH. The conjugates prevented resveratrol crystallization in aqueous media, while genipin crosslinking enhanced resistance to simulated gastrointestinal digestion and inhibited premature resveratrol release, increasing the fraction expected to reach the colon. Collectively, this system enables colonic co-delivery of carbohydrate, peptides, and resveratrol, providing a novel strategy for promoting beneficial-microbiota and gut-health. Full article

Spike density is an important component of wheat spike architecture and is determined by the combined effects of spike-axis elongation and spikelet number. In this study, we characterized an ethyl methanesulfonate (EMS)-induced recessive dense-spike mutant, ds, which was obtained from EMS mutagenesis of the wheat cultivar YN21 in 2013 and displays a field-visible compact spike architecture associated with a shortened spike axis, reduced spike internode spacing, and increased spikelet number. Genetic analysis showed that all F₁ plants exhibited normal spikes and that segregation in the F₂ population fitted a 3:1 ratio, supporting control by a single recessive nuclear gene. Through genome-wide marker-based linkage screening, enlarged-population validation, and fine mapping, ds was delimited to an approximately 864.819 kb interval between ID2B2796 and ID2B7615 on chromosome 2B. This interval contains 11 high-confidence annotated genes, including F-box protein, actin, ubiquitin-conjugating enzyme, ribosomal protein L16, RecX, plant cysteine oxidase, PI4KIIγ, and two adjacent GA3OX-family-related genes. Integrated RNA-seq and RT-qPCR analyses showed that the two adjacent GA3OX-family-related genes were expressed in young spikes and exhibited reduced expression in ds-sib relative to WT-sib. These expression data support their retention as plausible, non-exclusive candidates but do not establish causality. Transcriptome analysis further revealed changes in hormone-related pathways, cell-wall organization, carbohydrate metabolism, and transcription-factor regulation. These results provide a reliable genetic basis for further molecular cloning of ds and suggest that altered hormone- and growth-related transcriptional responses may be associated with dense-spike formation in wheat. Full article

Glycoclusters are important molecular tools for studying carbohydrate–protein interactions. It is advantageous to derive glycoclusters from carbohydrate-based scaffolds. Modulating the chair conformation of the scaffolding monosaccharide between ⁴C₁ and ¹C₄ enables the variation in the spatial organisation of the resulting glycoclusters, allowing the consequences for carbohydrate recognition in biological systems to be studied. Recently, we introduced a xylose derivative capable of adopting two complementary chair conformations, which was conjugated to glycoligands via Suzuki–Miyaura cross-coupling to afford homobivalent glycoclusters. Here, we expand this approach by further exploring the potential of xylose as a conformationally ‘switchable’ carbohydrate scaffold. Two additional features were introduced, (i) alkyne groups to facilitate conjugation reactions through click chemistry, and (ii) orthogonal protection to enable the synthesis of heterobivalent glycoclusters in addition to homobivalent analogues. This strategy enabled the synthesis of a focused library of homo- and heterobilvalent glycoclusters, which were subjected to preliminary biological evaluation. Notably, inversion of the chair conformation of the xyloside scaffold exerted a significant effect on the potency of the respective compounds as inhibitors of mannose-specific bacterial adhesion. Full article

The surface of cancer cells is covered in abnormal carbohydrate antigens that facilitate tumor growth, immune evasion and metastasis. Overexpressed and often specific to cancer cells, these tumor-associated carbohydrate antigens (TACAs) offer a valuable handle for targeted immunotherapy and were soon targeted by TACA–protein conjugate vaccines. Despite good initial results, sTn-KLH conjugate Theratope^® failed in clinical trials fifteen years ago for failure to improve life expectancy. This has been attributed to poor immunogenicity, inhomogeneous expression of TACAs within tumors, and vaccine carrier interference. This review covers the two decades of subsequent effort to overcome these limitations and the now large toolbox available to vaccine researchers to improve the outcome of anticancer vaccines: analogues and conformation-locked mimics of TACAs, monomolecular multivalent vaccines, more biologically relevant presentation of TACAs through clusters and glycopeptides, and a new generation of vaccine carriers to reduce carrier interference, immune reaction, or provide simple modular vaccine delivery platforms. Full article

Background: Group A Streptococcus (GAS) induces a wide spectrum of human diseases, ranging from superficial infections to life-threatening invasive conditions and post-infectious sequelae such as rheumatic heart disease, posing a heavy global health burden. Critically, there is still no licensed commercial vaccine against GAS, making the development of novel, effective vaccines against this pathogen an urgent and crucial unmet medical need. Methods: We developed a dual-antigen nanoconjugate vaccine against GAS. The Group A Carbohydrate polyrhamnose backbone (GAC^PR) and truncated SLO were site-specifically conjugated via Protein Glycan Coupling Technology (PGCT) in engineered E. coli, and then linked to ferritin nanoparticles using the SnoopTag/SnoopCatcher system. Safety, immunogenicity, and protective efficacy were evaluated in murine models. Results: The nanovaccine was successfully synthesized with high purity. It elicited robust GAC- and SLO-specific IgG/IgG1 responses, conferred 90% survival against lethal GAS challenge (vs. 0–50% in controls), reduced bacterial loads in organs, and lowered inflammatory cytokines. Passive immunization with vaccine-induced serum also achieved 90% survival. No abnormal biochemical indicators, inflammatory responses, or organ pathology were observed. Conclusions: This study successfully developed a bivalent nanoparticle vaccine against GAS. This novel nanovaccine exhibits excellent safety, strong immunogenicity, and effective protection against GAS, providing a promising vaccine candidate. Full article

Different groups of microorganisms—namely lactic acid bacteria (LAB), coagulase-negative staphylococci (CNS), dairy propionibacteria, yeasts, and molds—play essential roles in producing safe fermented foods of animal and plant origin with high nutritional value and sensory quality. The acquisition of genetic traits with technological relevance by natural horizontal gene transfer (HGT) via transformation, conjugation, phage transduction, and other routes would broaden the spectrum of beneficial activities exerted by individual microbial strains with no limitations for their use in food. Therefore, this critical review aimed to identify the potential for natural genetic improvement of microbial species relevant to food technology, based on reports of natural genetic exchanges occurring in environmental niches and laboratory conditions. Results showed that the species most frequently involved in natural HGT is Lactiplantibacillus plantarum, followed by Streptococcus thermophilus and Lactococcus lactis. Extensive HGT events enabling adaptation to food have been observed in domesticated filamentous fungi. The transferred traits of technological relevance include resistance to various stress factors, exopolysaccharide (EPS) and bacteriocin production, protein and amino acid utilization, phage immunity, lactose and citrate metabolism in dairy species, and use of plant carbohydrates in vegetable adapted species. Methods suitable for detecting HGT events in microbial communities have been developed and can aid in isolating improved strains for use in fermented foods. Full article

Background: As essential biomolecules composed of proteins and carbohydrate moieties, glycoproteins play pivotal roles in numerous biological processes. The glycosylation level plays a crucial role in determining the functionality of glycoproteins. Therefore, the precise quantification of glycan components in proteins holds significant importance for research on and development of polysaccharide–protein-conjugated vaccines. Methods: In this study, a novel glycan quantification approach was developed, leveraging analytical ultracentrifugation (AUC) technology that synergistically utilizes ultraviolet wavelength absorption and interference data to directly determine glycan mass fractions in glycoproteins. Results: This methodology expands the analytical framework for glycoproteins while retaining the intrinsic advantages of AUC, enabling analysis in native states with high reproducibility as indicated by low standard deviation across replicates. Conclusions: The approach was implemented in our proprietary AUC data analysis software called AUCAgent (v1.8.8), providing a new method for glycoprotein quantification and polysaccharide ratio determination in polysaccharide-protein-conjugate vaccines. Full article

Biomolecule–photosensitizer conjugates have rapidly evolved into one of the most powerful strategies for improving the selectivity, efficacy, and translational potential of photodynamic therapy (PDT). By integrating photosensitizers (PSs) with carbohydrates, amino acids, peptides, aptamers, proteins, cofactors, vitamins or antibodies, these constructs overcome long-standing limitations of classical PDT, including poor solubility, insufficient tumour accumulation, and strong dependence on oxygen availability. Beyond enhancing receptor-mediated uptake and enabling precise interactions with the tumour microenvironment (TME), bioconjugation also modulates aggregation, photochemical properties, intracellular accumulation, and immune system activation. A particularly transformative trend is the emergence of supramolecular architectures in which photosensitizers form defined nanostructured aggregates with peptides or proteins. Once considered an undesirable phenomenon, aggregation is now recognized as a tenable feature that governs photochemical behaviour. Engineered aggregates can undergo environment-triggered disassembly to monomeric, photoactive states, or operate as semiconductor-like nanodomains capable of Type I reaction through symmetry-breaking charge separation. This shift toward oxygen-independent radical pathways offers a promising solution to the challenge of hypoxia, a hallmark of the TME that severely compromises conventional Type II PDT. Parallel advances in 3D experimental platforms such as tumour organoids and organ-on-chip systems provide physiologically relevant validation of these conjugates, enabling the assessment of penetration, subcellular localization, immunogenic cell death, and therapeutic synergy within realistic TME conditions. Collectively, the integration of biomolecular targeting with controlled supramolecular design is redefining the landscape of PDT. Future progress will depend on designing conjugates that retain high activity under hypoxia, engineering dynamic aggregate states, and systematically validating these systems in advanced TME-mimetic models. Together, these developments position biomolecule–photosensitizer conjugates as a versatile and increasingly less oxygen-dependent class of next-generation phototherapeutic agents. Full article

Mesothelioma is characterized by the inactivation of tumor suppressor genes, with frequent mutations in neurofibromin 2 (NF2), BRCA1-associated protein 1 (BAP1), and cyclin-dependent kinase inhibitor 2A (CDKN2A). These mutations lead to disruptions in the Hippo signaling pathway and histone methylation, thereby promoting tumor growth. NF2 mutations result in Merlin deficiency, leading to uncontrolled cell proliferation, whereas BAP1 mutations impair chromatin remodeling and hinder DNA damage repair. Emerging molecular targets in mesothelioma include mesothelin (MSLN), oxytocin receptor (OXTR), protein arginine methyltransferase (PRMT5), and carbohydrate sulfotransferase 4 (CHST4). MSLN-based therapies, such as antibody–drug conjugates and immunotoxins, have shown efficacy in clinical trials. OXTR, upregulated in mesothelioma, is correlated with poor prognosis and represents a novel therapeutic target. PRMT5 inhibition is being explored in tumors with MTAP deletions, commonly co-occurring with CDKN2A loss. CHST4 expression is associated with improved prognosis, potentially influencing tumor immunity. Immune checkpoint inhibitors targeting PD-1/PD-L1 have shown promise in some cases; however, resistance mechanisms remain a challenge. Advances in multi-omics approaches have improved our understanding of mesothelioma pathogenesis. Future research will aim to identify novel therapeutic targets and personalized treatment strategies, particularly in the context of epigenetic therapy and combination immunotherapy. Full article

Fluorination of carbohydrates is a promising strategy to produce glycomimetics with improved pharmacological properties, such as increased metabolic stability, bioavailability and protein-binding affinity. Fluoroglycans are not only of interest as inhibitors and chemical probes but are increasingly being used to develop potential synthetic vaccine candidates for cancer, HIV and bacterial infections. Despite their attractiveness, the synthesis of fluorinated oligosaccharides is still challenging, emphasizing the need for efficient protocols that allow for the site-specific incorporation of fluorine atoms (especially at late stages of the synthesis). This is particularly true for the development of fully synthetic vaccine candidates, whose (modified) carbohydrate antigen structures (glycotopes) per se comprise multistep synthesis routes. Based on a known minimal protective epitope from the capsular polysaccharide of S. pneumoniae serotype 8, a panel of six novel F-glycotope mimetics was synthesized, equipped with amine linkers for subsequent conjugation to immunogens. Next to the stepwise assembly via fluorinated building blocks, the corresponding 6F-substituted derivatives could be obtained by microwave-assisted, nucleophilic late-stage fluorination of tri- and tetrasaccharidic precursors in high yields. The described synthetic strategy allowed for preparation of the targeted fluorinated oligosaccharides in sufficient quantities for future immunological studies. Full article

The aim of this study was to compare the concentration of phenolic compounds, glucosinolates, proteins, sugars and vitamin C between kohlrabi (Brassica oleracea var. acephala gongylodes), Savoy cabbage (B. oleracea sabauda), Brussels sprouts (B. oleracea gemmifera), cauliflower (B. oleracea botrytis), radish (Raphanus sativus) and garden cress (Lepidium sativum) microgreens for their antioxidant and hypoglycemic potential. In addition, we applied an in vitro-simulated system of human digestion in order to track the bioaccessibility of the selected phenolic representatives, and the stability of the microgreens’ antioxidant and hypoglycemic potential in terms of α-amylase and α-glucosidase inhibition after each digestion phase. Using spectrophotometric and RP-HPLC methods with statistical analyses, we found that garden cress had the lowest soluble sugar content, while Savoy cabbage and Brussels sprouts had the highest glucosinolate levels (76.21 ± 4.17 mg SinE/g dm and 77.73 ± 3.33 mg SinE/g dm, respectively). Brussels sprouts were the most effective at inhibiting protein glycation (37.98 ± 2.30% inhibition). A very high positive correlation (r = 0.830) between antiglycation potential and conjugated sinapic acid was recorded. For the first time, the antidiabetic potential of microgreens after in vitro digestion was studied. Kohlrabi microgreens best inhibited α-amylase in both initial and intestinal digestion (60.51 ± 3.65% inhibition and 62.96 ± 3.39% inhibition, respectively), and also showed the strongest inhibition of α-glucosidase post-digestion (19.22 ± 0.08% inhibition). Brussels sprouts, cauliflower, and radish had less stable α-glucosidase than α-amylase inhibitors during digestion. Kohlrabi, Savoy cabbage, and garden cress retained inhibition of both enzymes after digestion. Kohlrabi antioxidant capacity remained unchanged after digestion. The greatest variability was seen in the original samples, while the intestinal phase resulted in the most convergence, indicating that digestion reduced differences between the samples. In conclusion, this study highlights the potential of various microgreens as sources of bioactive compounds with antidiabetic and antiglycation properties. Notably, kohlrabi microgreens demonstrated significant enzyme inhibition after digestion, suggesting their promise in managing carbohydrate metabolism and supporting metabolic health. Full article

Bile acids (BAs) are the main endogenous modulators of the composition and metabolic activity of the intestinal microbiota. In the present work, the effect of conjugated (glycodeoxycholic, glycocholic, taurodeoxycholic, taurocholic acids) and free BAs [cholic acid (CA) and deoxycholic acid (DCA)] on the survival, biological molecules, and structural and surface properties of two potential probiotic lactic acid bacteria (LAB) was evaluated. For this, viability assays, Raman spectroscopy, scanning electron microscopy (SEM), and zeta potential (ZP) measurements were employed. Our results evidenced that free BAs were more toxic than conjugates, with CA being significantly more harmful than deoxycholic acid (DCA). RAMAN studies show that BAs modify the bands corresponding to proteins, lipids, carbohydrates, and DNA. SEM showed that BAs cause surface distortions with depressions and fold formation, as well as incomplete cell division. DCA was the one that least altered the ZP of bacteria when compared to CA and taurodeoxycholic acid, with gradual changes towards more positive values. In general, the magnitude of these effects was different according to the BA and its concentration, being more evident in the presence of CA, even at low concentrations, which would explain its greater inhibitory effect. This work provides solid evidence on the effects of BAs on LAB that will allow for the development of strategies by which to modulate the composition of the microbiota positively. Full article

The sensitivity of immunoassays is generally limited by the low signal reporter/recognition element ratio. Nanomaterials serving as the carriers can enhance the loading number of signal reporters, thus improving the detection sensitivity. However, the general immobilization strategies, including direct physical adsorption and covalent coupling, may cause the random orientation and conformational change in proteins, partially or completely suppressing the enzymatic activity and the molecular recognition ability. In this work, we proposed a strategy to load recognition elements of antibodies and enzyme labels using boronic acid-modified metal-organic frameworks (MOFs) as the nanocarriers for signal amplification. The conjugation strategy was proposed based on the boronate ester interactions between the carbohydrate moieties in antibodies and enzymes and the boronic acid moieties on MOFs. Both enzymes and MOFs could catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H₂O₂, therefore achieving dual signal amplification. To indicate the feasibility and sensitivity of the strategy, colorimetric immunoassays of prostate specific antigen (PSA) were performed with boronic acid-modified Cu-MOFs as peroxidase mimics to catalyze TMB oxidation and nanocarriers to load antibody and enzyme (horseradish peroxidase, HRP). According to the change in the absorbance intensity of the oxidized TMB (_oxTMB), PSA at the concentration range of 1~250 pg/mL could be readily determined. In addition, this work presented a site-specific and oriented conjugation strategy for the modification of nanolabels with recognition elements and signal reporters, which should be valuable for the design of novel biosensors with high sensitivity and selectivity. Full article

Vaccine development against group A Streptococcus (GAS) has gained traction in the last decade, fuelled by recognition of the significant worldwide burden of the disease. Several vaccine candidates are currently being evaluated in preclinical and early clinical studies. Here, we investigate two conjugate vaccine candidates that have shown promise in mouse models of infection. Two antigens, the J8 peptide from the conserved C-terminal end of the M protein, and the group A carbohydrate lacking N-acetylglucosamine side chain (ΔGAC) were each conjugated to arginine deiminase (ADI), an anchorless surface protein from GAS. Both conjugate vaccine candidates combined with alum adjuvant were tested in a non-human primate (NHP) model of pharyngeal infection. High antibody titres were detected against J8 and ADI antigens, while high background antibody titres in NHP sera hindered accurate quantification of ΔGAC-specific antibodies. The severity of pharyngitis and tonsillitis signs, as well as the level of GAS colonisation, showed no significant differences in NHPs immunised with either conjugate vaccine candidate compared to NHPs in the negative control group. Full article

Conjugation with glucose (G) and fructose (F) via the Maillard reaction under the wet-heating condition is a natural and non-toxic method of improving the technological functions of 7S/11S proteins in different kinds of gels. It may be used as an affordable supply of emulsifiers and an excellent encapsulating matrix for gels. This study aimed to create a glucose/fructose-conjugated 7S/11S soy protein via the Maillard reaction. The conjugation was confirmed by determining the SDS-PAGE profile and circular dichroism spectra. In addition, these conjugates were comprehensively characterized in terms of grafting degree, browning degree, sulfhydryl content, surface hydrophobicity (H₀), and differential scanning calorimetry (DSC) through various reaction times (0, 24, 48, and 72 h) to evaluate their ability to be used in food gels. The functional characteristics of the 7S/11S isolate–G/F conjugate formed at 70 °C, with a high degree of glycosylation and browning, were superior to those obtained at other reaction times. The SDS-PAGE profile indicated that the conjugation between the 7S and 11S proteins and carbohydrate sources of G and F through the Maillard reaction occurred. Secondary structural results revealed that covalent interactions with G and F affected the secondary structural components of 7S/11S proteins, leading to increased random coils. When exposed to moist heating conditions, G and F have significant potential for protein alteration through the Maillard reaction. The results of this study may provide new insights into protein modification and establish the theoretical basis for the therapeutic application of both G and F conjugation with soy proteins in different food matrixes and gels. Full article