Search Results (213)

Diacylglycerol-O-acyltransferase 1 (DGAT1, EC 2.3.1.20) is a pivotal enzyme in plant triacylglycerol (TAG) biosynthesis. Previous work identified conserved di-arginine (R) motifs (R-R, R-X-R, and R-X-X-R) in its N-terminal cytoplasmic acyl-CoA binding domain. To elucidate their functional significance, we engineered R-rich sequences in the N-termini of Tropaeolum majus and Zea mays DGAT1s. Comparative analysis with their respective non-mutant constructs showed that deleting or substituting R with glycine in the N-terminal region of DGAT1 markedly reduced lipid accumulation in both Camelina sativa seeds and Saccharomyces cerevisiae cells. Immunofluorescence imaging revealed co-localization of non-mutant and R-substituted DGAT1 with lipid droplets (LDs). However, disruption of an N-terminal di-R motif destabilizes DGAT1, alters LD organization, and impairs recombinant oleosin retention on LDs. Further evidence suggests that the di-R motif mediates DGAT1 retrieval from LDs to the endoplasmic reticulum (ER), implicating its role in dynamic LD–ER protein trafficking. These findings establish the conserved di-R motifs as important regulators of DGAT1 function and LD dynamics, offering insights for the engineering of oil content in diverse biological systems. Full article

In response to the growing demand for sustainable protein sources, this study explores the valorization of sunflower meal—a by-product of oil extraction—as a protein-rich ingredient suitable for human nutrition. The aim was to optimize the extraction process and assess the nutritional and safety profile of the resulting protein flour. Mechanical stirring, ultrasound-assisted, and CO₂-assisted extraction methods were evaluated, with mechanical stirring selected for optimization due to its scalability and energy efficiency. A Taguchi L9 orthogonal array was employed to evaluate the effects of pH, temperature, and sample mass on protein content. A first-order regression model was developed and validated (R² = 0.86, p < 0.05), identifying optimal conditions at pH 10.0, 30 °C, and 60 g per 500 mL of distilled water. Under these conditions, protein content reached 49.87%. The extracted protein flour exhibited improved nutritional quality with high protein content, moderate solubility (53.4%), and favorable amino acid composition—particularly rich in glutamic acid, aspartic acid, and arginine. Safety analyses confirmed the absence of detectable aflatoxins and very low PAH levels. These results support the use of sunflower protein concentrate as a sustainable, nutritionally valuable, and safe ingredient for functional food applications. Further studies are recommended to improve functional properties and assess sensory acceptance. Full article

Background: The positive effects of oral nutritional supplements (ONS) on postoperative outcomes have been well recognized in several previous studies. However, to date, little data has been available with respect to determining the best immune modulating supplement to use and what its impact might be in thoracic surgery. The aim of this study was to evaluate the role of preoperative immune-nutritional supplement intake as predictor of postoperative cardiopulmonary complications (CPCs) in patients undergoing uniportal video-assisted thoracoscopic (uVATS) lung resection. Methods: This is a retrospective, observational study enrolling consecutive patients who underwent uVATS lung resections for cancer from January 2022 to December 2024 in the context of the Enhanced Pathway of Care (EPC) Program. All patients were evaluated by a nutritionist and dietetics team during the preoperative phase. The nutritional protocol consisted of 250 mL ONS rich in arginine, omega-3-fatty acids, and nucleotides to be taken twice a day for 5–7 days before surgery. Results: Four hundred ninety-one patients were enrolled: 277 patients underwent anatomic lung resection and 214 underwent wedge resection (WR). Utilizing the univariate analysis, we found that in patients undergoing anatomic lung resection, not-ONS-intake, high Body Mass Index (BMI), and arrythmia were correlated with a higher CPCs rate compared to the patients without nutritional supplementation (7.2% ONS vs. 15% not-ONS, p = 0.04; BMI 28.4 kg/m² vs. BMI 26.4 kg/m², p = 0.03; 31.2% arrythmia vs. 9.4% no-arrythmia, p < 0.01). These correlations, except for BMI, were confirmed after stepwise logistic regression. Alternately, in patients undergoing WR, hypertension and low-FEV1% were associated with a higher CPCs rate (5.1% hypertension vs. 0.4% no-hypertension, p = 0.02; FEV1% 79.7% vs. 95%, p = 0.01). Conclusions: Our results demonstrated that preoperative ONS after uVATS anatomic lung resection, in the context of an EPC program, influences the postoperative period, reducing the CPCs rate. Full article

Soybean (Glycine max) seeds are rich in amino acids, offering key nutritional and physiological benefits. In this study, 290 soybean accessions from the USDA Germplasm Collection based in Urbana, IL Information Network (GRIN) were analyzed. Four Genome-Wide Association Study (GWAS) models—Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK), Mixed Linear Model (MLM), Fixed and Random Model Circulating Probability Unification (FarmCPU), and Multi-Locus Mixed Model (MLMM)—identified two significant Single Nucleotide Polymorphisms (SNPs) associated with arginine content: Gm06_19014194_ss715593808 (LOD = 9.91, 3.91% variation) at 19,014,194 bp on chromosome 6 and Gm11_2054710_ss715609614 (LOD = 9.05, 19% variation) at 2,054,710 bp on chromosome 11. Two candidate genes, Glyma.06g203200 and Glyma.11G028600, were found in the two SNP marker regions, respectively. Genomic Prediction (GP) was performed for arginine content using several models: Bayes A (BA), Bayes B (BB), Bayesian LASSO (BL), Bayesian Ridge Regression (BRR), Ridge Regression Best Linear Unbiased Prediction (rrBLUP), Random Forest (RF), and Support Vector Machine (SVM). A high GP accuracy was observed in both across- and cross-populations, supporting Genomic Selection (GS) for breeding high-arginine soybean cultivars. This study holds significant commercial potential by providing valuable genetic resources and molecular tools for improving the nutritional quality and market value of soybean cultivars. Through the identification of SNP markers associated with high arginine content and the demonstration of high prediction accuracy using genomic selection, this research supports the development of soybean accessions with enhanced protein profiles. These advancements can better meet the demands of health-conscious consumers and serve high-value food and feed markets. Full article

Alternative splicing (AS) is a pivotal post-transcriptional mechanism that expands the functional diversity of the proteome by enabling a single gene to generate multiple mRNA and protein isoforms. This process, which involves the differential inclusion or exclusion of exons and introns, is tightly regulated by splicing factors (SFs), such as serine/arginine-rich proteins (SRs), heterogeneous nuclear ribonucleoproteins (hnRNPs), and RNA-binding motif (RBM) proteins. These factors recognize specific sequences, including 5′ and 3′ splice sites and branch points, to ensure precise splicing. While AS is essential for normal cellular function, its dysregulation is increasingly implicated in cancer pathogenesis. Aberrant splicing can lead to the production of oncogenic isoforms that promote tumorigenesis, metastasis, and resistance to therapy. Furthermore, such abnormalities can cause the loss of tumor-suppressing activity, thereby contributing to cancer development. Importantly, abnormal AS events can generate neoantigens, which are presented on tumor cell surfaces via major histocompatibility complex (MHC) molecules, suggesting novel targets for cancer immunotherapy. Additionally, splice-switching oligonucleotides (SSOs) have shown promise as therapeutic agents because they modulate splicing patterns to restore normal gene function or induce tumor-suppressive isoforms. This review explores the mechanisms of AS dysregulation in cancer, its role in tumor progression, and its potential as a therapeutic target. We also discuss innovative technologies, such as high-throughput sequencing and computational approaches, that are revolutionizing the study of AS in cancer. Finally, we address the challenges and future prospects of targeting AS for personalized cancer therapies, emphasizing its potential in precision medicine. Full article

The proteolytic processing of the SARS-CoV-2 spike glycoprotein by host cell membrane-associated proteases is a key step in both the entry of the invading virus into the cell and the release of the newly generated viral particles from the infected cell. Because of the critical importance of this step for the viral infectivity cycle, it has been a target of extensive efforts aimed at identifying highly specific protease inhibitors as potential antiviral agents. An alternative strategy to disrupt the pre-fusioviden processing of the SARS-CoV-2 S glycoprotein aims to protect the substrate rather than directly inhibit the proteases. In this work, we focused on furin, a serine protease located primarily in the Golgi apparatus, but also present on the cell membrane. Its cleavage site within the S glycoprotein is located within the stalk region of the latter and comprises an arginine-rich segment (SPRRARS), which fits the definition of the Cardin–Weintraub glycosaminoglycan recognition motif. Native mass spectrometry (MS) measurements confirmed the binding of a hexadecameric peptide representing the loop region at the S1/S2 interface and incorporating the furin cleavage site (FCS) to heparin fragments of various lengths, as well as unfractionated heparin (UFH), although at the physiological ionic strength, only UFH remains tightly bound to the FCS. The direct LC/MS monitoring of FCS digestion with furin revealed a significant impact of both heparin fragments and UFH on the proteolysis kinetics, although only the latter had IC50 values that could be considered physiologically relevant (0.6 ± 0.1 mg/mL). The results of this work highlight the importance of the long-range and relatively non-specific electrostatic interactions in modulating physiological and pathological processes and emphasize the multi-faceted role played by heparin in managing coronavirus infections. Full article

Salt stress is one of the most prominent abiotic stresses. Behind the intricate adaptive responses of plants to salt stress, the regulation of gene expression assumes a pivotal role. Complementing transcriptional mechanisms, post-transcriptional regulation performed by RNA-binding proteins provides an additional layer of control through sophisticated molecular machinery. RBPs interact with both RNA molecules and protein partners to coordinate RNA metabolism and, thus, fine-tune the expression of salt-responsive genes, enabling plants to rapidly adapt to ionic challenges. This review systematically evaluates the functional roles of RBPs localized in distinct subcellular compartments, including nuclear, cytoplasmic, chloroplastic, and mitochondrial systems, in mediating post-transcriptional regulatory networks under salinity challenges. Specific classes of RBPs are discussed in detail, including glycine-rich RNA-binding proteins (GR-RBPs), serine/arginine-rich splicing factors (SR proteins), zinc finger domain-containing proteins, DEAD-box RNA helicases (DBRHs), KH domain-containing proteins, Pumilio domain-containing proteins (PUMs), pentatricopeptide repeat proteins (PPRs), and RBPs involved in cytoplasmic RNA granule formation. By integrating their subcellular localization and current mechanistic insights, this review concludes by summarizing the current knowledge and highlighting potential future research directions, aiming to inspire further investigations into the complex network of RBPs in modulating plant responses to salt stress and facilitating the development of strategies to enhance plant salt tolerance. Full article

Objectives: This study investigated the effects of 2-week ingestion of hemp fiber (high and low doses) versus placebo bars on gut permeability and plasma metabolite shifts during recovery from 2.25 h intensive cycling. Hemp hull powder is a rich source of two bioactive compounds, N-trans-caffeoyl tyramine (NCT) and N-trans-feruloyl tyramine (NFT), with potential gut health benefits. Methods: The study participants included 23 male and female cyclists. A three-arm randomized, placebo-controlled, double-blind, crossover design was used with two 2-week supplementation periods and 2-week washout periods. Supplement bars provided 20, 5, or 0 g/d of hemp hull powder. Participants engaged in an intensive 2.25 h cycling bout at the end of each of the three supplementation periods. Five blood samples were collected before and after supplementation (overnight fasted state), and at 0 h-, 1.5 h-, and 3 h-post-exercise. Five-hour urine samples were collected pre-supplementation and post-2.25 h cycling after ingesting a sugar solution containing 5 g of lactulose, 100 mg of ¹³C mannitol, and 1.9 g of mannitol in 450 mL of water. An increase in the post-exercise lactulose/¹³C mannitol ratio (L:¹³CM) was used as the primary indicator of altered gut permeability. Other outcome measures included muscle damage biomarkers (serum creatine kinase, myoglobin), serum cortisol, complete blood cell counts, and shifts in plasma metabolites using untargeted metabolomics. Results: No trial differences were found for L:¹³CM, cortisol, blood cell counts, and muscle damage biomarkers. Orthogonal partial least-squares discriminant analysis (OPLSDA) showed distinct trial differences when comparing high- and low-dose hemp fiber compared to placebo supplementation (R2Y = 0.987 and 0.995, respectively). Variable Importance in Projection (VIP) scores identified several relevant metabolites, including 3-hydroxy-4-methoxybenzoic acid (VIP = 1.9), serotonin (VIP = 1.5), 5-hydroxytryptophan (VIP = 1.4), and 4-methoxycinnamic acid (VIP = 1.4). Mummichog analysis showed significant effects of hemp fiber intake on multiple metabolic pathways, including alpha-linolenic acid, porphyrin, sphingolipid, arginine and proline, tryptophan, and primary bile acid metabolism. Conclusions: Hemp fiber intake during a 2-week supplementation period did not have a significant effect on post-exercise gut permeability in cyclists (2.25 h cycling bout) using urine sugar data. On the contrary, untargeted metabolomics showed that the combination of consuming nutrient-rich hemp fiber bars and exercising for 135 min increased levels of beneficial metabolites, including those derived from the gut in healthy cyclists. Full article

Protamine is a promising marine-derived bioactive compound that is highly arginine-rich and has demonstrated unique advantages in medical and biological research. This study, for the first time, investigates the molecular mechanisms underlying the immunomodulatory effects of Salmon Protamine Sulfate (SPS), Symplectoteuthis oualaniensis Protamine (SOP), and its polyethylene glycol (PEG) derivative (SOP-PEG) on RAW264.7 macrophages. The results demonstrate that both SOP and SOP-PEG significantly enhance the proliferation of RAW264.7 cells by promoting the secretion of pro-inflammatory cytokines and nitric oxide (NO), increasing ROS production, and improving antioxidant capacity, in comparison to SPS. Elevated ROS levels play a crucial role in enhancing macrophage immune activity, while the enhanced antioxidant defense mechanisms help maintain redox homeostasis and protect against oxidative stress-induced cellular damage. A Western blot analysis reveals that SOP and SOP-PEG notably regulate the expression of key proteins associated with the PI3K/Akt signaling pathway and anti-apoptotic mechanisms. Furthermore, a flow cytometry analysis indicates a significant increase in the G2/M-phase cell population in the treatment groups, which is corroborated by Western blot data showing alterations in critical regulatory proteins. Notably, SOP-PEG exhibits the strongest effects in regulating macrophage immune activity, which can be attributed to the enhanced stability and prolonged bioactivity resulting from the PEGylation of SOP. This comprehensive study reveals how SOP and SOP-PEG enhance macrophage immune function through multiple mechanisms, including PI3K/Akt activation, redox regulation, and cell cycle modulation. It provides valuable insights and a theoretical foundation for their potential applications in immunotherapy and immune regulation. Full article

Background/Objectives: The Canadian goldenrod (Solidago canadensis L.) is one of the most widespread species of the genus Solidago from the Asteraceae family. It has a rich composition of biologically active compounds and is traditionally used to address kidney, urinary tract, and liver diseases. Previously, it was proven that the S. canadensis extract obtained with a 40% ethanol solution had the most promising anti-inflammatory and hepatoprotective activity. Therefore, this extract was selected for the further formulation of amino acid preparations and 3D-printed dosage forms. The aims of the present study were to investigate the chemical composition, toxicity, and antimicrobial, anti-inflammatory, and hepatoprotective activity of S. canadensis dry extract, its amino acid preparations, and 3D-printed dosage forms. Results: A total of 18 phenolic compounds and 14 amino acids were determined in the extracts. The S. canadensis herb extracts were verified to be practically non-toxic preparations (toxicity class V, LD₅₀ > 5000 mg/kg). They also showed moderate antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, and β-hemolytic Streptococcus pyogenes. The most pronounced hepatoprotective activity was observed with S. canadensis herb extract and its amino acid preparations with phenylalanine, alanine, and lysine at a dose of 25 mg/kg body weight. The most pronounced anti-inflammatory activity was found with S. canadensis herb extract and its preparation with arginine. According to the calculated docking score array and the analysis of binding modes in the active sites of COX-1 and COX-2, the flavonoid fraction and caffeic acid in the S. canadensis extracts presented moderate inhibitory activity. Conclusions: The development of innovative 3D-printed oral dosage forms represents a promising strategy to formulate dietary supplements or pharmaceutical preparations for these herbal extracts. Full article

Shrimp are highly favored by consumers for their delicious taste and rich nutritional value. However, reports of allergic reactions caused by shrimp and its derivatives have been increasing, significantly impacting consumer health and posing a growing global food safety concern. This article introduces the structure and biochemical characteristics of major allergenic proteins in shrimp, including tropomyosin (TM), arginine kinase, sarcoplasmic calcium-binding protein, myosin light chain, troponin C, and hemocyanin. Currently, there is no effective treatment for shrimp allergies, and prevention is mainly achieved by avoiding consumption. The study of shrimp allergen sensitization reduction technology is of great significance to the development of hypoallergenic or desensitized products. The article provides a detailed overview of the effects of common processing techniques, including physical, chemical, biological, and combined methods, on the allergenicity of shrimp allergens; for instance, the binding rate to immunoglobulin E (IgE) was reduced by 73.59% after treating TM with high pressure (500 MPa) at 55 °C for 10 min and the recognition rate of TM to IgE decreased by 89.4% on average after treating TM with pepsin (30 μg/mL, pH 2) for 2 h. These techniques provide references for the development of hypoallergenic aquatic products or desensitized foods. Full article

In recent years, arginine-rich basic proteins have garnered significant attention due to their essential roles in various biological processes. However, the potential of marine-derived proteins in this domain remains largely unexplored. This study presents, for the first time, the isolation and purification of a 14.3 kDa protamine (SOP) from the mature spermatogonial tissues of Symplectoteuthis oualaniensis. Additionally, we obtained an 18.5 kDa PEGylated derivative, SOP-PEG. The physicochemical properties of both SOP and SOP-PEG were comprehensively characterized using SEM, FTIR, CD, and TGA. PEGylation markedly altered the surface morphology, secondary structure, and thermal stability of SOP. In vitro studies demonstrated that PEGylation significantly enhanced the biocompatibility of SOP, leading to improved proliferation of L-929 fibroblasts. Furthermore, both SOP and its PEGylated derivative (SOP-PEG) regulated the cell cycle, activated the PI3K-Akt signaling pathway, and modulated anti-apoptotic mechanisms, suggesting their potential to support cell survival and facilitate tissue regeneration. Notably, SOP-PEG exhibited superior bioactivity, likely attributable to its enhanced delivery efficiency conferred by PEGylation. Collectively, these findings underscore the promising applications of SOP and SOP-PEG in regenerative medicine and highlight the pivotal role of PEGylation in augmenting the bioactivity of SOP. Full article

L-carnosine (Car) is an endogenous dipeptide with significant potential in drug discovery for neurodegenerative diseases, while TAT1, a small arginine-rich peptide derived from the HIV-1 trans-activator protein (TAT), is known to stimulate proteasome activity. In this study, three isomeric peptides were synthesised by incorporating the Car moiety at the N-terminus, C-terminus, or central position of the TAT1 sequence. To differentiate these isomers, high-resolution and energy-resolved CID MS/MS experiments were conducted. The resulting MS/MS spectra showed a high degree of similarity among the peptides, predominantly characterised by fragment ion peaks arising from arginine-specific neutral losses. Energetic analysis was similarly inconclusive in resolving the isomers. However, Principal Component Analysis (PCA) enabled clear differentiation of the three peptides by considering the entire MS/MS spectra rather than focusing solely on precursor ion intensities or major fragment peaks. PCA loadings revealed distinct fragment ions for each peptide, albeit with lower intensities, providing insights into consecutive fragmentation patterns. Some of these specific peaks could also be attributed to scrambling during fragmentation. These results demonstrate the potential of PCA as a simple chemometric tool for semi-automated peak identification in complex MS/MS spectra. Full article

The purpose of this research was to investigate the characteristics of different plant-based sources rich in protein, chickpea flour (CPF), hazelnut oil cake (HOC), soy protein isolate (SPI) and concentrate (SPC), and pea protein isolate (PPI) for their subsequent use in the manufacture of meat analogs. The protein sources were analyzed for dry matter, ash, protein, fat, starch, dietary fiber, water holding capacity, granulosity, color parameters (L*, a*, b*, C*, YI), antioxidant activity before and after gastrointestinal in vitro digestion, and amino acid and mineral compositions. The highest dry matter content was determined in hazelnut oil cake and pea protein isolate. For the protein content, maximum values were obtained for the protein isolate and concentrate samples, from 52.80% to 80.50%, followed by hazelnut oil cake and chickpea flour. The water-holding capacity of all plant sources was directly influenced by the values of protein content, dietary fiber, and granulosity. The results obtained after gastrointestinal digestion also showed quite significant antioxidant activity, which is due to the process of hydrolysis and denaturation of plant-based protein sources in the gastrointestinal tract. Major amino acids identified in the analyzed samples were glutamic acid, leucine, arginine, phenylalanine, serine, valine, alanine, and tyrosine from minerals P, Na, Mg, and Ca. Principal component analysis (PCA) was used to illustrate the relationship between physicochemical characteristics, amino acid composition, mineral composition, and antioxidant activity determined in the plant-based materials. Full article

Candida species, normally part of the healthy human flora, can cause severe opportunistic infections when their population increases. This risk is even greater in immunocompromised individuals. Women using intrauterine contraceptive devices (IUDs) are at higher risk for IUD-associated vulvovaginal candidiasis (VVC) because the device provides a surface for biofilm formation. This biofilm formation allows the normal flora to become opportunistic pathogens, leading to symptoms of VVC such as hemorrhage, pelvic pain, inflammation, itching and discharge. VVC is often linked to IUD use, requiring the prompt removal of these devices for effective treatment. This study evaluated the activity of the arginine-rich peptide “protamine” against Candida albicans, Candida tropicalis and Candida krusei isolated from IUD users who had signs of VVC. The antimicrobial activity was measured using the agar disk diffusion and microbroth dilution methods to determine the minimum inhibitory concentration (MIC). The MIC values of protamine against C. albicans, C. tropicalis and C. krusei are 32 μg mL⁻¹, 64 μg mL⁻¹ and 256 μg mL⁻¹, respectively. The determined MIC of protamine was used for a biofilm inhibition assay by crystal violet staining. Protamine inhibited the biofilm formation of the VVC isolates, and its mechanisms were studied through scanning electron microscopy (SEM) and a reactive oxygen species (ROS) assay. The disruption of cell membranes and the induction of oxidative stress appear to be key mechanisms underlying its anti-candidal effects. The results from an in vitro assay support the potential use of protamine as an antibiofilm agent to coat IUDs in the future for protective purposes. Full article