Search Results (1,371)

Scorpion venom is a rich source of bioactive compounds with significant potential for anticancer drug development. Its diverse molecular composition, including neurotoxins, antimicrobial peptides, and enzymes, provides a vast library for therapeutic innovation. Proteomic analyses have characterized venom composition in several species, while further functional assays have clarified their anticancer mechanisms. This review synthesizes current knowledge on scorpion venom-derived peptides with demonstrated anticancer activity, which selectively target ion channels, induce apoptosis, or disrupt tumor microenvironments. Where available, we highlight proteomic studies that have identified these components and discuss their structural features relevant to drug design. We also examine clinical applications and the challenges in translating venom peptides into therapies. The crucial and growing role of proteomics in this field, particularly for venom fractionation, component identification, and structural characterization, is critically evaluated. Full article

This study aimed to screen and identify a novel immune-enhancing peptide and explore the molecular mechanism. Five novel peptides were identified from Agaricus blazei Murrill (ABM), and their secondary structure components consisted of random coil (50.5%), α-helix (28.9%), β-turn (15.6%), and β-sheet (5.0%). A novel peptide (LNEDELRDA) with a molecular weight of 1074.0989 Da could bind with PI3K, AKT, mTOR, IL-6, IL-1β, and TNF-α through hydrogen bonding interactions, and the binding energies were −8.1, −8.3, −7.2, −6.0, −7.4, and −5.8 kcal/mol, respectively. This peptide was synthesized and validated for immune-enhancing ability, showing the strongest immune-enhancing capacity by increasing the cell viability and phagocytic activity of RAW 264.7 macrophages, significantly promoting the production of NO, cytokines TNF-α, IL-1β, and IL-6 in cells, and up-regulating the mRNA and protein expression levels of the PI3K/AKT/mTOR signaling pathway. Our results are the first to reveal that ABM-derived peptide LNEDELRDA could be considered as a promising food-borne immunomodulator that could contribute to enhancing immune function. Full article

Leaf senescence is a developmental process that allows nutrients to be remobilized and transported to sink organs. Previously, papain-like cysteine proteases (PLCPs) have been found to be highly expressed during leaf senescence in different plant species. In this study, we analyzed active PLCPs in barley (Hordeum vulgare L.) leaves during the terminal stage of natural senescence. Anion exchange chromatography of protein extracts from barley leaves, harvested six weeks after anthesis, followed by activity assays using the substrates Z-FR-AMC and Z-RR-AMC, revealed a single prominent peak corresponding to active PLCPs. This hydrolytic activity was completely inhibited by E-64, a potent and irreversible inhibitor of cysteine proteases. Fractions enriched for PLCP activity were affinity-labeled with DCG-04 and subjected to SDS-PAGE fractionation, separating two major bands at 43 and 38 kDa. These bands were analyzed using tandem mass spectrometry, allowing the identification of eleven PLCPs. Identified enzymes belong to eight PLCP subfamilies, including CTB/cathepsin B-like (HvPap-19 and -20), RD19/cathepsin F-like (HvPap-1), ALP/cathepsin H-like (HvPap-12 or aleurain), SAG12/cathepsin L-like A (HvPap-17), CEP/cathepsin L-like B (HvPap-14), RD21/cathepsin L-like D (HvPap-6 and -7), cathepsin L-like E (HvPap-13 and -16), and XBCP3 (HvPap-8). Among the identified PLCPs, HvPap-6 was the most abundant. Peptides corresponding to HvPap-6 were identified in both the 43 kDa and 38 kDa bands in approximately the same quantity based on total spectral count. Thus, our results indicate that two active HvPap-6 isoforms can be isolated from barley leaves at late senescence. Full article

Background/Objectives: Biofilm formation by Acinetobacter baumannii contributes to its persistence in clinical settings and resistance to antibiotic treatment. This study aims to identify and characterize antimicrobials from lactic acid bacteria (LAB) using molecular and in silico approaches that can prevent and disrupt A. baumannii biofilms, assess their antimicrobial host range, and define their synergy with current antibiotics. Methods: Thirteen LAB isolates from the Human Microbiome Project were screened for anti-biofilm activity against A. baumannii. Conditioned media was further tested against six ESKAPE pathogens and three skin commensals. Lentilactobacillus hilgardii was selected for detailed study and antimicrobial peptide (AMP) prediction analysis due to limited toxicity toward commensals. In silico identified peptides were synthesized and tested individually and in combination with sub-MIC doses of an antibiotic. Results: Conditioned media from five LAB species (Lentilactobacillus hilgardii, Lentilactobacillus buchneri, Ligilactobacillus ruminis, Limosilactobacillus fermentum, and Limosilactobacillus antri) significantly inhibited A. baumannii biofilm formation and reduced biomass of mature biofilms. LAB-conditioned media also exhibited broad-spectrum activity against ESKAPE pathogens, though effects on commensals varied. Bioinformatically predicted AMPs from L. hilgardii inhibited planktonic A. baumannii growth but showed no direct biofilm activity even at high doses. However, AMPs were found to synergize with sub-MIC doses of meropenem against mature biofilms leading to decolonization. Conclusions: Our study provides a comprehensive platform for the discovery and characterization of AMPs and supports using commensal bacteria to reduce, prevent, and decolonize biofilms from pathogenic bacteria in community and nosocomial settings. Full article

Alzheimer’s disease (AD) requires early and accurate identification of affected brain regions, which can be achieved through the detection of specific biomarkers to enable timely intervention. Carbon nanomaterials (CNMs), including graphene derivatives, carbon nanotubes, graphitic carbon nitride, carbon black, fullerenes, and carbon dots, offer high conductivity, large electroactive surface area, and versatile surface chemistry that enhance biosensor performance. While such properties benefit a wide range of transduction principles (e.g., electrochemical, optical, and plasmonic), this review focuses on their role in electrochemical biosensors. This review summarizes CNM-based electrochemical platforms reported from 2020 to mid-2025, employing aptamers, antibodies, and molecularly imprinted polymers for AD biomarker detection. Covered topics include fabrication strategies, transduction formats, analytical performance in complex matrices, and validation. Reported devices achieve limits of detection from the femtomolar to picogram per milliliter range, with linear ranges typically spanning 2–3 orders of magnitude (e.g., from femtomolar to picomolar, or from picogram to nanogram per milliliter levels). They exhibit high selectivity against common interferents such as BSA, glucose, uric acid, ascorbic acid, dopamine, and non-target peptides, along with growing capabilities for multiplexing and portable operation. Remaining challenges include complex fabrication, limited long-term stability and reproducibility data, scarce clinical cohort testing, and sustainability issues. Opportunities for scalable production and integration into point-of-care workflows are outlined. Full article

Type 1 Diabetes Mellitus (T1D) is an autoimmune disease characterized by the destruction of pancreatic β-cells, predominantly manifesting in childhood or adolescence. The lack of clearly interpretable biological markers in the early stages, combined with the insidious onset of the disease, poses significant challenges to early diagnosis and the implementation of preventive strategies. The applicability of classic T1D biomarkers for understanding the mechanisms of the autoimmune process, preclinical diagnostics and treatment efficiency is limited. Despite advances in next-generation sequencing (NGS) technologies, which have enabled large-scale genome-wide association studies (GWASs) and the identification of polygenic risk scores (PRSs) associated with T1D predisposition, as well as progress in bioinformatics approaches for assessing dysregulated gene expression, no universally accepted risk assessment model or definitive predictive biomarker has been established. Until now, the use of new promising biomarkers for T1D diagnostics is limited by insufficient evidence base. However, they have great potential for the development of diagnostic methods on their basis, which has been shown in single or serial large-scale studies. This critical review covers both well-known biomarkers widely used in clinical practice, such as HLA-haplotype, non-HLA SNPs, islet antigen autoantibodies, C-peptide, and the promising ones, such as cytokines, cfDNA, microRNA, T1D-specific immune cells, islet-TCR, and T1D-specific vibrational bands. Additionally, we highlight new approaches that have been gaining popularity and have already demonstrated their potential: GWAS, single-cell transcriptomics, identification of antigen-specific T cells using scRNA-seq, and FTIR spectroscopy. Although some of the biomarkers, in our opinion, are still limited to a research context or are far from being implemented in clinical diagnostics of T1D, they have the greatest potential of being applied in clinical practice. When integrated with the monitoring of the classical autoimmune diabetes markers, they would increase the sensitivity and specificity during diagnostics of early and preclinical stages of the disease. This critical review aims to evaluate the current landscape of classical and emerging biomarkers in autoimmune diabetes, with a focus on those enabling early detection—prior to extensive destruction of pancreatic islets. Another goal of the review is to focus the attention of the scientific community on the gaps in early T1D diagnostics, and to help in the selection of markers, targets, and methods for scientific studies on creating novel diagnostic panels. Full article

Circular RNAs are a class of stable non-coding RNAs generated through a back-splicing mechanism. They are now recognized as central players in cell function and are no longer considered byproducts of transcription. CircRNAs regulate gene expression at the transcriptional, post-transcriptional, and translational levels by interacting with various molecules. They act as sponges for miRNAs and proteins, molecular scaffolds, and can also be translated into peptides. Although advances in next-generation sequencing and PCR methods have improved their identification and quantification, technical and bioinformatic challenges remain. Increasing evidence shows their involvement in cardiovascular diseases such as heart failure, hypertrophy, fibrosis, and atherosclerosis, with protective or deleterious effects depending on the context. Given their presence in biological fluids and extracellular vesicles, they can be considered promising biomarkers, but their therapeutic applications are still under investigation. Future studies including a better understanding of their mechanisms of action, the development of standardized validation methods, and potential clinical applications (prevention, early diagnosis, personalized therapies) in diseases are still needed. This review provides an updated overview of the knowledge regarding circRNAs and their translational role in health and disease with a particular focus on cardiovascular diseases. Full article

Arrhythmogenic cardiomyopathy (ACM; MIM #107970) is a primitive heart muscle disease characterized by progressive myocardial loss and fibrosis or fibrofatty replacement, predisposing patients to ventricular arrhythmias, sudden cardiac death, and heart failure. Despite advances in imaging and genetics, early diagnosis remains challenging due to incomplete penetrance, variable phenotypic expressivity, and the fact that fatal arrhythmic events may often occur in the early stages of the disease. In this context, the identification of reliable biomarkers could enhance diagnostic accuracy, support risk stratification, and guide clinical management. This narrative review examines the current landscape of potential and emerging biomarkers in ACM, including troponins, natriuretic peptides, inflammatory proteins, microRNAs, fibrosis-related markers, and other molecules. Several of these biomarkers have demonstrated associations with disease severity, arrhythmic burden, or structural progression, although their routine clinical utility remains limited. The increasing relevance of genetic testing and non-invasive tissue characterization—particularly through cardiac imaging techniques—should also be emphasized as part of a multimodal diagnostic strategy in which biomarkers may play a complementary role. Although no single biomarker currently meets the criteria for a standalone diagnostic application, ongoing research into multi-marker panels and novel molecular targets offers promising perspectives. In conclusion, the integration of circulating biomarkers with imaging findings, genetic data, and clinical parameters may open new avenues for improving early detection and supporting personalized therapeutic strategies in patients with suspected ACM. Full article

This study investigates the anti-obesity and antidiabetic potential of P. palmata extracts produced through sequential enzymatic and alkaline treatments. Among the treatment groups, the extract treated solely with Alcalase^® (Alc) demonstrated the highest protein content (10.11 ± 0.15%) and degree of hydrolysis (30.36 ± 0.77%), significantly outperforming other treatments (p < 0.05). The Alc extract also exhibited superior inhibitory activity against porcine pancreatic lipase and α-amylase, achieving the lowest IC₅₀ for lipase (2.29 ± 0.87 mg.mL⁻¹) and showing significant enzyme inhibition across all tested concentrations (p < 0.05). Ultrafiltration of the Alc extract revealed that peptide fractions < 1 kDa and 1–3 kDa were most effective in enzyme inhibition, with IC₅₀ values of 3.25–3.55 mg.mL⁻¹ for both lipase and α-amylase. Peptides were identified via LC-MS/MS analysis and database searching using SequestHT, resulting in 536 sequences, of which bioinformatic screening yielded 51 non-toxic, non-allergenic candidates (PeptideRanker score > 0.6); four of these contained known inhibitory motifs for lipase and α-amylase. Molecular docking confirmed strong binding affinities between these peptides and their respective enzymes, supporting their potential as natural enzyme inhibitors. These findings indicate the functional food potential of Alcalase^®-derived P. palmata peptides for managing obesity and type 2 diabetes. Full article

Background: Currently available immunological tests for SARS-CoV-2 assess only antibody responses. Despite the growing evidence that T cells play a crucial role in protection, especially against emerging viral variants, no routine test is available to determine T cell immunity. The prognostic value of SARS-CoV-2-specific antibodies for determining whether individuals are immune and protected against disease remains uncertain. This is in part due to the following: (a) specificity and limitations such as the sensitivity of antibody tests, and (b) the lack of correlation between antibody titers (quantity) and the antiviral function of antibodies (quality). Approximately a quarter of SARS-CoV-2-infected patients with symptoms fail to show seroconversion in serological assays. Methods: The current report describes the development and application of a whole-blood-based assay to detect previous exposure to SARS-CoV-2. Whole blood is stimulated with SARS-CoV-2-derived peptides identified during assay development and stimulation-induced cytokines quantified using a multiplex testing platform. The resulting cytokine profiles are generated using computational tools to identify previous exposure to the virus. Results: The application of the assay revealed a lack of self-awareness of individuals’ COVID-19 infection history and demonstrated the value of this new assay to assess the prevalence of SARS-CoV-2 exposure history and immunity in populations. Conclusions: Positive responses in this assay can facilitate the identification of underlying causes of unexplained symptoms and provide clinically actionable insights for healthcare applications, including in the continued conundrum of post-acute sequela of SARS-CoV-2 infection (PASC or “long COVID”), for which both diagnosis and management remain challenging. Full article

Background/Objectives: SARS-CoV-2 pandemic led to the identification of peptide-based main protease (M^pro) inhibitors. The overwhelming majority of them carry an electrophilic warhead and a γ-lactam at the P1 position. During the selectivity assessment of an in-house Michael acceptors targeting SARS-CoV-2 M^pro, we unexpectedly observed a significant inhibition of human cathepsin S (hCatS). Methods: The biological investigation of three compounds (i.e., SPR38, SPR39, and SPR41) against hCatS was performed. The binding mode of SPRs was investigated by docking and molecular dynamics simulations. Results: Biological investigation has corroborated that hCatS is sensitive to peptide-based analogues harbouring γ-lactam at the P1 position and a vinyl methyl ketone warhead. In silico studies revealed that despite being solvent exposed, the γ-lactam at P1 might be involved in water-mediated H-bonds that could be optimized to gain inhibition potency and selectivity. Conclusions: The molecules repurposing of peptide-based SARS-CoV-2 M^pro inhibitors carrying the γ-lactam at the P1 site could pave the way for the identification of novel potent and selective hCatS ligands. Full article

Spiders of the Sicarius genera (Araneae: Sicariidae) are commonly known as six-eyed sand spiders. Of the species described in Latin America, the species S. thomisoides has previously been shown to possess venom with a toxic potential comparable to that observed in the venom of the spider L. laeta. Although identifying the phospholipase D activity in the venom of S. thomisoides, it is still unknown what other components are part of the venom. In this study, we described the identification of the main protein components of S. thomisoides venom, revealing that the phospholipase D family were the majority toxins, followed by Astacin-like metalloproteinases and serine proteases. Additionally, the presence of CRISP-type allergens and peptides from the U-PHTX-Pmx family was identified for the first time in venoms from Sicarius genera. Identifying the components of the Sicarius spider venom is an essential step to understanding its toxicological potential. Full article

The tree bean (Parkia timoriana), an underutilized legume valued for its nutritional profile, represents a potential source of bioactive peptides for diabetes management. To our knowledge, this is the first study to identify and characterize DPP-IV inhibitory peptides derived from tree bean seed protein hydrolysates. The tree bean proteins were digested with trypsin, thermolysin, chymotrypsin, pepsin, and simulated gastrointestinal (SGI) enzymes, among which SGI hydrolysis yielded the highest degree of hydrolysis (14%) and strongest DPP-IV inhibitory activity (IC₅₀ = 1289 ± 58 µg/mL). Guided by DPP-IV inhibitory assays, sequential fractionation using strong cation exchange and RP-HPLC yielded the most potent fraction, H5, with an IC₅₀ of 949 ± 50 µg/mL. After peptide identification and synthesis, APLGPF (AF6) emerged as the most potent inhibitor, with an IC₅₀ of 396 ± 18 µM. Enzyme kinetics revealed a non-competitive inhibition mechanism, corroborated by molecular docking, which indicated binding at an allosteric site of DPP-IV. Furthermore, AF6 remained stable under simulated gastrointestinal digestion and enzymatic exposure, highlighting its resistance to proteolysis. Taken together, these findings highlight P. timoriana as an underexplored source of peptides with DPP-IV inhibitory activity and identify AF6 as a promising lead for developing functional foods or nutraceuticals aimed at type 2 diabetes management. Full article

Obesity is a worldwide problem, and lowering pancreatic lipase (PL) activity is an effective strategy to counteract it. In this study, pancreatic lipase-inhibitory (PL-I) peptides were isolated and purified from Chlorella pyrenoidosa protein hydrolysates (CPPHs) using ultrafiltration and Sephadex gel chromatography (Sephadex G-25). A total of 858 peptides were identified by liquid chromatography–tandem mass spectrometry (LC-MS/MS). Four novel PL-I peptides (FLSQPF, VWTPI, IVGPF, and IPYPL) were virtually screened using molecular docking and subsequently synthesized, with VWTPI exhibiting the highest PL inhibition. Moreover, the inhibition of the enzyme by VWTPI was a mixture of competitive and non-competitive inhibition, with an inhibition constant (Ki) of 7.27 mg/mL. Molecular docking showed that VWTPI interacts with the PL active center by hydrogen bonding, hydrophobic contacts, van der Waals forces, and π-π stacking. This study suggests that peptides from Chlorella pyrenoidosa could be used as lipid-lowering agents to prevent and cure obesity. Full article

Detection of cancer biomarkers at the earliest stages of disease progression is commonly assumed to extend the overall quality of life for cancer patients as the result of earlier clinical management of the disease. Therefore, there is an urgent need for the development of standardized, sensitive, robust, and commonly available screening and diagnostic tools for detecting the earliest signals of neoplastic pathology progression. Recently, a new paradigm of cancer control, known as multi-cancer detection (MCD), evolved, which measures the composition of cancer-related molecular analytes in the patient’s fluids using minimally invasive techniques. In this respect, the “Holy Grail” of cancer researchers and bioengineers for decades has been composing a repertoire or molecular sensing probes that would allow for the diagnosis, prognosis, and monitoring of cancer diseases via their interaction with cell-secreted and cell-associated cancer antigens and biomarkers. Therefore, the current trend in screening and detection of cancer-related pathologies is the development of portable biosensors for mobile laboratories and individual use. Phage display, since its conception by George Smith 40 years ago, has emerged as a premier tool for molecular evolution in molecular biology with widespread applications including identification and screening of cancer biomarkers, such as Circulating Cellular Communication Network Factor 1 (CCN1), an extracellular matrix-associated signaling protein responsible for a variety of cellular functions and has been shown to be overexpressed as part of the response to various pathologies including cancer. We hypothesize that CCN1 protein can be used as a soluble marker for the early detection of breast cancer in a multi-cancer detection (MCD) platform. However, validated probes have not been identified to date. Here, we screened the multi-billion clone landscape phage display library for phages interacting specifically with immobilized CCN1 protein. Through our study, we discovered a panel of 26 different phage-fused peptides interacting selectively with CCN1 protein that can serve for development of a novel phage-based diagnostic platform to monitor changes in CCN1 serum concentration by liquid biopsy. Full article