Search Results (107)

Orange allergy is estimated to account for up to 3–4% of food allergies. Major allergens identified in orange (Citrus sinensis) include Cit s 1 (germin-like protein) and Cit s 2 (profilin), while Cit s 3 (non-specific lipid transfer protein, nsLTP) and Cit s 7 (gibberellin-regulated protein) have also been described. The objective of this study was to investigate the presence and IgE-binding capacity of germin-like proteins in citrus fruits other than oranges. We describe five patients with immediate allergic reactions after orange ingestion. All patients underwent skin prick tests (SPT) to aeroallergens and common food allergens, prick-by-prick testing with orange, lemon, and mandarin (pulp, peel, seeds), total IgE, specific IgE (sIgE), anaphylaxis scoring (oFASS), and the Food Allergy Quality of Life Questionnaire (FAQLQ-AF). Protein extracts from peel and pulp of orange, lemon, and mandarin were analyzed by Bradford assay, SDS-PAGE, and IgE immunoblotting using patient sera. Selected bands were identified by peptide mass fingerprinting. A 23 kDa band was recognized by all five patients in orange (pulp and peel), lemon (peel), and mandarin (peel). This band was consistent with Cit s 1, a germin-like protein already annotated in the IUIS allergen database for orange but not for lemon or mandarin. Peptide fingerprinting confirmed the germin-like identity of the 23 kDa bands in all three citrus species. Germin-like proteins of approximately 23 kDa were identified as IgE-binding components in peel extracts of orange, lemon, and mandarin, and in orange pulp. These findings suggest a potential shared allergen across citrus species that may contribute to allergic reactions independent of LTP sensitization. Full article

This study investigated thermophilic bacterial communities from two Algerian hot springs: Hammam Debagh (94–98 °C), recognized as the second hottest spring in the world, and Hammam Bouhadjar (61–72 °C), one of the hottest in northwest Algeria. Thirty isolates were obtained, able to grow between 45 °C and 80 °C, tolerating pH 5.0–12.0 and NaCl concentrations up to 3%. Colonies displayed diverse morphologies, from circular and smooth to star-shaped and Saturn-like forms. All isolates were characterized as Gram-positive, catalase-positive rods or filamentous bacteria. Identification by MALDI-TOF, rep-PCR and 16S rRNA sequencing classified them mainly within Bacillus, Brevibacillus, Aneurinibacillus, Geobacillus, and Aeribacillus, with Geobacillus predominating. Rep-PCR provided higher resolution, revealing intra-species diversity overlooked by MALDI-TOF MS and 16S rRNA. A subset of six isolates, mainly Geobacillus spp., was selected based on phenotypic and genotypic diversity and tested for antimicrobial activity against thermophilic target isolates from the same hot spring environments. Strong inhibition zones (~24 mm) were observed, with Geobacillus thermoleovorans B8 displaying the highest activity. Optimization on Modified Nutrient Agar medium with Gelrite enhanced antimicrobial production and inhibition clarity. These findings highlight the ecological and biotechnological significance of thermophilic bacteria from Algerian geothermal ecosystems. While this study focused on microbial interactions within thermophilic communities, the promising inhibitory profiles reported here provide a foundation for future research targeting foodborne and antibiotic-resistant pathogens, as part of broader efforts in biopreservation and sustainable antimicrobial development. Full article

During radiotherapy, X-rays can deliver significant doses of ionising radiation to both cancerous and healthy tissue, often leading to undesirable side effects that compromise patient outcomes. While the cellular effects of such therapeutic X-ray exposures are well studied, the impact on extracellular matrix (ECM) proteins remains poorly understood. This study characterises the response of ECM proteins, including the major tissue components collagen I and fibronectin (FN), to X-ray doses similar to those used in clinical practice (50 Gy, as employed in breast radiotherapy, and 100 Gy), using a combination of gel electrophoresis, biochemical assays, and mass spectrometry-based peptide location fingerprinting (PLF) analysis. In purified protein solutions, 50 Gy X-ray exposure led to the fragmentation of constituent collagen I α chains. Irradiation of purified plasma FN (pFN) induced localised changes in peptide yields (detected by liquid chromatography and tandem mass spectrometry (LC-MS/MS) and PLF) and enhanced its binding to collagen I. In complex environments, such as newly synthesised fibroblast-derived ECM and mature ex vivo breast tissue, X-ray exposure induced peptide yield changes in not only collagen I and FN but also key basement membrane proteins, including collagen IV, laminin, and perlecan. Intracellular proteins associated with gene expression (RPS3, MeCP2), the cytoskeleton (moesin, plectin), and the endoplasmic reticulum (calnexin) were also found to be impacted. These X-ray-induced structural changes may impair the ECM integrity and alter cell–ECM interactions, with potential implications for tissue stiffening, fibrosis, and impaired wound healing in irradiated tissues. Full article

The study of bacteriocins has significantly enhanced our understanding of microbial interactions, notably within the genus Streptococcus. Among the most functionally diverse and clinically relevant bacteriocins are those belonging to the lantibiotic class, which exhibit potent antimicrobial properties and are central to the competitive dynamics of streptococcal species. This review focuses on the discovery and characterization of bacteriocins produced by Streptococcus pyogenes and Streptococcus salivarius, emphasizing their biological significance within their exclusive human host. A cornerstone of these studies has been the development and application of the pioneer agar culture-based bacteriocin detection methodology, known as streptococcal bacteriocin fingerprinting. This approach has proven invaluable for the initial detection and differentiation of a wide array of bacteriocin-like inhibitory substances (BLIS) in streptococcal populations. A central theme of this review is the diverse biological roles of lantibiotics in S. pyogenes and S. salivarius, particularly in relation to microbial competition, colonization dynamics, and host interactions. The expression of lantibiotic determinants provides distinct advantages to the producing strain, including enhanced niche establishment and the ability to suppress competing microbes. Furthermore, the presence of specific lantibiotic immunity mechanisms safeguards the producer from self-inhibition and potential antagonism from closely related competitors. In S. pyogenes, lantibiotic production has been implicated in virulence modulation, raising important questions about its role in pathogenicity and host immune evasion. Conversely, S. salivarius, a prominent commensal and probiotic candidate species, utilizes its lantibiotic arsenal to confer colonization benefits and mediate beneficial interactions, especially within the oral and upper respiratory tract microbiomes. The implications of in situ lantibiotic expression extend beyond microbial ecology, presenting opportunities for innovative probiotic and therapeutic applications. The potential for harnessing bacteriocin-producing streptococci in antimicrobial interventions, particularly in combating antibiotic-resistant pathogens, underscores the translational relevance of these findings. This review integrates historical and contemporary perspectives on streptococcal bacteriocin research, providing insights into future avenues for leveraging these bioactive peptides in clinical and biotechnological contexts. Full article

The South China Sea is rich in cone snail resources, known for producing conotoxins with diverse biological activities such as analgesic, anticancer, and insecticidal effects. In this study, five vermivorous cone snail samples were collected from the South China Sea and their crude venom was extracted to investigate the variations in venom components and activities, aiming to identify highly active samples for further research. Cluster analysis using reverse-phase high-performance liquid chromatography (RP-HPLC) fingerprints and mitochondrial cytochrome c oxidase I (COI) gene sequences revealed that the diversity of venom components across different conotoxin species is genetically correlated. Activity assays demonstrated that all five cone snail venoms exhibited lethal effects on insects and zebrafish. Notably, the crude venom of Conus quercinus showed the highest insecticidal activity with an LD₅₀ of 0.6 μg/mg, while C. tessellatus venom exhibited the most potent zebrafish lethality with an LD₅₀ of 0.2 μg/mg. Furthermore, the crude venom from four cone snail species demonstrated toxicity against ovarian cancer cells, and only C. caracteristicu venom displayed significant analgesic activity. This study systematically identifies cone snail samples with promising insecticidal, anticancer, and analgesic properties, paving the way for the development and utilization of cone snail resources from the South China Sea and offering a novel approach for advancing marine peptide drug research. Full article

Background and Objectives: As a medicinal and food homologous substance, Eupolyphaga steleophaga is renowned for its potential health benefits, including anti-tumor effects, immune system support, and anti-inflammatory properties. Eupolyphaga steleophaga polypeptides have demonstrated significant biological activity, including the regulation of coagulation and lipid metabolism. However, the peptide composition of Eupolyphaga steleophaga requires further clarification to facilitate quality control improvements and a deeper investigation into its pharmacological effects. Therefore, this study aimed to simulate the digestive absorption process of Eupolyphaga steleophaga following oral administration and identify its enzymatic components to enhance quality control. Methods: The digestive absorption process was simulated using artificial gastric fluid and pepsin. A fingerprinting method based on ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC-MS)(Acquire UPLC-Synapt G2-Si HDMS, Waters Corporation, Milford, MA, USA) was developed to identify 63 enzymatic components. The enzymolysis polypeptide fingerprint detection method was used to analyze 10 batches of Eupolyphaga steleophaga sourced from Harbin No. 4 Traditional Chinese Medicine Factory. Chromatographic collection was performed using an ACQUITY UPLC BHE C18 column. Gradient elution was carried out using a mixture of 0.1% formic acid with acetonitrile and 0.1% formic acid with water, with an average flow rate of 0.3 mL/min, a column temperature of 40 °C, and an injection volume of 2 μL. The mass spectrometry (MS) conditions were set as follows: the ion source was operated in positive electrospray ionization (ESI+) mode, with a capillary voltage of 2.8 kV and a sampling cone voltage of 40 V. The ion-source temperature was maintained at 110 °C, while the desolvation temperature was set to 400 °C. The cone gas flow rate was 50 L/h, and the desolvation gas flow rate was 800 L/h. The range for the collection of mass-to-charge ratios (m/z) was between 50 and 1200. Results: The UHPLC-MS method demonstrated high accuracy, repeatability, and stability, successfully identifying 63 enzymatic components of Eupolyphaga steleophaga. Furthermore, polypeptide markers for 63 selected components were identified in all 10 batches of Eupolyphaga steleophaga medicinal materials. This approach was validated by including numerical values such as retention times and peak areas, confirming its reliability for quality control enhancement. Conclusions: This novel UHPLC-MS approach serves as a powerful tool for advancing quality control strategies in veterinary medicine, particularly for animal-derived medicines. It lays a solid foundation for subsequent pharmacological studies of Eupolyphaga steleophaga polypeptides, offering a more reliable means to explore their biological activities and therapeutic potential. Full article

Background: The increasing prevalence of drug-resistant tuberculosis (TB) underscores the urgent need for novel antimicrobial agents. Methods: This study integrates cultivation optimization, nuclear magnetic resonance (NMR) fingerprinting, and principal component analysis (PCA) to explore microbial secondary metabolites as potential anti-TB agents. Results: Using the combined approach, 11 bioactive compounds were isolated and identified, all exhibiting anti-Mycobacterium bovis BCG activity. Notable findings include borrelidin, a potent threonyl-tRNA synthetase inhibitor with broad biological activities, and L-O-Lac-L-Val-D-O-Hiv-D-Val, a peptide isolated for the first time from a plant endophyte, demonstrating broad-spectrum antimicrobial activity. Additionally, elaiophylin and polycyclic tetramate macrolactams (PTMs) displayed significant bactericidal effects, with elaiophylin achieving complete BCG inhibition at 72 h and PTMs marking their first reported anti-TB activity. The study also identified bafilomycins as potent scaffolds for anti-TB drug development, showcasing rapid bactericidal activity at low MIC values. Conclusions: These findings emphasize the value of microbial metabolites as a reservoir of bioactive compounds and provide new avenues for developing next-generation anti-TB therapies. Full article

Hazelnuts are frequently involved in IgE-mediated reactions and are the main cause of nut allergies in Europe. Most food products are processed before human consumption. Food processing can modify the structure, properties, and function of proteins, and as a result, the IgE-binding capacity of allergens can be affected. In this study, we aimed to investigate epitope changes caused by the roasting of hazelnuts using epitope fingerprinting. Rabbit sera were raised against hazelnut proteins, and their epitopes were characterized. Immunoassays using specific polyclonal antibodies from rabbits targeting the main allergens in hazelnuts revealed marked reductions in the levels of Cor a 1 (PR-10), Cor a 11 (7S globulin), and Cor a 14 (2S albumin). However, rabbit antibodies can recognize different epitopes. Using antibodies that are different and characterized could help establish reliable methods for estimating the effects of treatments on the allergenicity of foods. In this work, we provide the first practical application that could lead to sets of peptide epitopes to compare and standardize immune diagnostics, even for complex protein preparations. Full article

Many non-natural amino acids can be incorporated by biological systems into coded functional peptides and proteins. For such incorporations to be effective, they must not only be compatible with the desired function but also evade various biochemical error-checking mechanisms. The underlying molecular mechanisms are complex, and this problem has been approached previously largely by expert perception of isomer compatibility, followed by empirical study. However, the number of amino acids that might be incorporable by the biological coding machinery may be too large to survey efficiently using such an intuitive approach. We introduce here a workflow for searching real and computed non-natural amino acid libraries for biosimilar amino acids which may be incorporable into coded proteins with minimal unintended disturbance of function. This workflow was also applied to molecules which have been previously benchmarked for their compatibility with the biological translation apparatus, as well as commercial catalogs. We report the results of scoring their contents based on fingerprint similarity via Tanimoto coefficients. These similarity scoring methods reveal candidate amino acids which could be substitutable into modern proteins. Our analysis discovers some already-implemented substitutions, but also suggests many novel ones. Full article

A comprehensive LC-MS study examined the venom components of the solitary scoliid wasp Scolia oculata. Online mass fingerprinting showed that crude venom contains 25 small molecules (amino acids, biogenic amines, and nucleosides/nucleotides) and 45 peptides with MW 400-2700. The small molecules were identified by elemental composition analysis, and peptide sequences were determined by ESI-MS/MS and MALDI-TOF/TOF MS analyses. As major peptide components, a known peptide, β-scoliidine (DYVTVKGFSPLRKA), and three new peptides, γ-scoliidine (YVTVKGFSPLR), δ-scoliidine (YVTVKGFSPLREP) and ε-scoliidine (DYVTVKGFSPLREP) were identified, all of which are closely homologous to each other. Once the neuroprotective effects of β-scoliidine have already been described, the other three new scoliidine peptides were analyzed against oxidative stress-induced toxicity in PC12 neuronal cells by mitochondrial metabolism assay, and the structure-activity relationship was evaluated. Interestingly, pre-treatment with ε-scoliidine increased the mitochondrial metabolism of PC12 cells (106 ± 3.6%; p = 0.007) exposed to H₂O₂-induced oxidative stress in contrast to γ- and δ-scoliidines (77.6 ± 4.8 and 68.5 ± 4.1%, respectively) in compared to cells treated only H₂O₂ (75.8 ± 2.4%). These new peptides were also analyzed for enzyme inhibitor/substrate assays with angiotensin-converting enzyme (ACE), neprilysin (NEP), and acetylcholinesterase (AChE). In these assays, only δ- and ε-scoliidines increased the AChE activity (128.7 ± 3.8%; p = 0.01; and 116.8 ± 3.8% p = 0.03; respectively) in relation to basal activity (100.1 ± 1.6%). In addition, the four peptides were analyzed through in silico analysis, and none of them demonstrated possible hemolytic and toxic activities. In our study, the comprehensive LC-MS and MS/MS analyses of Scolia oculate venom identified four major peptide components of the venom β-, γ-, δ- and ε-scoliidines, and small differences in their primary structures are important to their neuroprotective properties. Full article

The objective of this study was to investigate the umami characteristics of soy sauce using electronic tongue evaluation and amino acid composition and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI−TOF MS) analysis. The soy sauce peptides were isolated from soy sauce using XAD−16 macroporous resin combined with ethanol solution. The results showed that the soy sauce peptide fraction eluted by 60% ethanol (SS−60%) exhibited a prominent umami taste, and the umami scores were highly positively correlated with the amino acid nitrogen contents of soy sauces. The umami scores of SS−60% were significantly positively correlated with the contents of free amino acids. Especially, Phe showed the highest positive correlation with the umami scores. In addition, five characteristic ion peaks with m/z at 499, 561, 643, 649, and 855 were identified in the peptide mass fingerprinting. Therefore, this study provides new insights into the umami characteristics for the taste evaluation and reality identification of soy sauce. Full article

The underdevelopment of adjuvant discovery and diversity, compared to core vaccine technology, is evident. On the other hand, antibiotic resistance is on the list of the top ten threats to global health. Immunomodulatory peptides that target a pathogen and modulate the immune system simultaneously are promising for the development of preventive and therapeutic molecules. Since investigating innate immunity in insects has led to prominent achievements in human immunology, such as toll-like receptor (TLR) discovery, we used the capacity of the immunomodulatory peptides of arthropods with concomitant antimicrobial or antitumor activity. An SVM-based machine learning classifier identified short immunomodulatory sequences encrypted in 643 antimicrobial peptides from 55 foe-to-friend arthropods. The critical features involved in efficacy and safety were calculated. Finally, 76 safe immunomodulators were identified. Then, molecular docking and simulation studies defined the target of the most optimal peptide ligands among all human cell-surface TLRs. SPalf2-453 from a crab is a cell-penetrating immunoadjuvant with antiviral properties. The peptide interacts with the TLR1/2 heterodimer. SBsib-711 from a blackfly is a TLR4/MD2 ligand used as a cancer vaccine immunoadjuvant. In addition, SBsib-711 binds CD47 and PD-L1 on tumor cells, which is applicable in cancer immunotherapy as a checkpoint inhibitor. MRh4-679 from a shrimp is a broad-spectrum or universal immunoadjuvant with a putative Th1/Th2-balanced response. We also implemented a pathway enrichment analysis to define fingerprints or immunological signatures for further in vitro and in vivo immunogenicity and reactogenicity measurements. Conclusively, combinatorial machine learning, molecular docking, and simulation studies, as well as systems biology, open a new opportunity for the discovery and development of multifunctional prophylactic and therapeutic lead peptides. Full article

Human pulmonary paragonimiasis, an emerging concern in North East India, frequently masquerades as pulmonary tuberculosis due to clinical and radiological similarities, leading to diagnostic challenges. This research aimed to harness the immunoblotting technique to discern immunodiagnostic protein antigens from both adult worm and excretory–secretory (ES) extracts of the prevalent Paragonimus westermani type 1 in Arunachal Pradesh, North East India. We studied the time kinetics of immunoreactive patterns in relation to the duration of infection in rodent models. Immunoblot analyses were also conducted using sera from ELISA-positive patients confirmed with paragonimiasis, facilitating the selection of antigenic extracts with diagnostic potential. Further, ES protein antigens were subjected to 2D immunoblot analysis and immunoreactive protein spots identified using MALDI-TOF MS. The immunoreactivity patterns of ES antigens with sera of paragonimiasis-positive patients were detailed, and specific immunoreactive protein antigens were pinpointed using peptide mass fingerprinting (MALDI-TOF). This work underscores the enhanced diagnostic accuracy when combining ELISA with immunoblotting for pulmonary paragonimiasis in regions like North East India, marked by co-existing helminth infections. Full article

In recent years, there has been renewed interest in the maintenance of food quality and food safety on the basis of metabolomic fingerprinting using vibrational spectroscopy combined with multivariate chemometrics. Nontargeted spectroscopy techniques such as FTIR, NIR and Raman can provide fingerprint information for metabolomic constituents in agricultural products, natural products and foods in a high-throughput, cost-effective and rapid way. In the current review, we tried to explain the capabilities of FTIR, NIR and Raman spectroscopy techniques combined with multivariate analysis for metabolic fingerprinting and profiling. Previous contributions highlighted the considerable potential of these analytical techniques for the detection and quantification of key constituents, such as aromatic amino acids, peptides, aromatic acids, carotenoids, alcohols, terpenoids and flavonoids in the food matrices. Additionally, promising results were obtained for the identification and characterization of different microorganism species such as fungus, bacterial strains and yeasts using these techniques combined with supervised and unsupervised pattern recognition techniques. In conclusion, this review summarized the cutting-edge applications of FTIR, NIR and Raman spectroscopy techniques equipped with multivariate statistics for food analysis and foodomics in the context of metabolomic fingerprinting and profiling. Full article

Thickness of lipid bilayer membranes is a key physical parameter determining membrane permeability and stability with respect to formation of through pores. Most membrane inclusions or impurities like amphipathic peptides, transmembrane peptides, lipid inclusions of a different molecular shape, lipid domains, and protein-lipid domains, locally deform the membrane. The detailed structure of the locally deformed region of the membrane is a kind of “fingerprint” for the inclusion type. However, most experimental methods allow determining only averaged parameters of membranes with incorporated inclusions, thus preventing the direct obtaining of the characteristics of the inclusion. Here we developed a model that allows the obtaining of characteristic parameters of three types of membrane inclusions (amphipathic peptides, transmembrane peptides, monolayer lipid patches) from experimentally observable dependencies of the average thickness of lipid bilayer on the surface concentration of the inclusions. In the case of amphipathic peptides, the model provided the peptide parameters that were in qualitative agreement with the available experimental data. Full article