Soluble Protein Research Articles

Exploration of the regulatory mechanism of pulsed electric field on the aggregation behavior of soybean protein isolates

As an emerging protein modification technology, pulsed electric field (PEF) technology in modifying soybean protein isolates (SPI) suffers from unclear mechanism and controversial changes in aggregation structure. To address these issues, the effects of PEF treatment with different electric field intensities (5–30 kV/cm) on the aggregation behavior and spatial structure of SPI were investigated. The results showed that the SPI aggregates exhibited a trend of depolymerization followed by reaggregation with the increase of PEF intensity. At 10 and 15 kV/cm, the polarization effect of PEF induced the unfolding of the tertiary structure of SPI, leading to the enhancement of the electronegativity of the side chains, and the electrostatic repulsive force between the molecules promoted the depolymerization of SPI aggregates. However, with the withdrawal of PEF, the structure of the SPI was partially reversible, resulting in a limited depolymerization effect. When the PEF intensity reached 20 kV/cm and above, SPI underwentstructure unfolding, subunit dissociation, continuous exposure of hydrophobic groups and sulfhydryl groups, and ultimately reaggregation mediated by hydrophobic interactions and disulfide bonding, resulting in the formation of high molecular weight soluble and insoluble protein aggregates. In addition, the formation of free radicals under strong electric fields (≥20 kV/cm) accelerated the oxidation of SPI and promoted the rapid formation of disulfide bonds. This study provides a theoretical basis for the targeted regulation of SPI aggregation structure by PEF.

Binding mechanism and structural characteristics of alloyed protein complex for enhanced solubility of hemp seed protein isolate

Despite the numerous health benefits and high digestibility of hemp seed protein isolate (HPI), its low solubility at neutral pH limits its utilization in the food industry. Therefore, we subjected insoluble HPI and soluble mung bean protein isolate (MBPI) to pH co-shifting under extremely alkaline conditions to form an alloyed protein complex (A-HM). At a mass ratio of HPI:MBPI of 50:50, A-HM exhibited the highest solubility (95.30 ± 0.99 %), and also had high resistance to heat treatment. Native PAGE demonstrated the formation of alloyed protein complexes, and particle size analysis revealed that A-HM exhibited small particle sizes and dispersion in water without aggregation of HPI. Owing to their small size, numerous hydrophobic residues and aromatic ring of HPI were exposed on the surface. Hydrophobic interactions predominantly governed the binding force involved in the formation of A-HM. Our findings may enhance HPI applications in the food industry, particularly in plant-based beverages.

Update on Tissue Factor Detection in Blood in 2024: A Narrative Review.

Tissue factor (TF) is a transmembrane protein essential for hemostasis. Different forms of active TF circulate in the blood, either as a component of blood cells and extracellular vesicles (EVs) or as a soluble plasma protein. Accumulating experimental and clinical evidence suggests that TF plays an important role in thrombosis. Many in-house and commercially available assays have been developed to measure TF-dependent procoagulant activity or antigen in blood and have shown promising results for the prediction of disease outcomes or the occurrence of thrombosis events in diseases such as cancer or infectious coagulopathies. This review addresses the different assays that have been published for measuring circulating TF antigen and/or activity in whole blood, cell-free plasma, and EVs and discusses the main preanalytical and analytical parameters that impact results and their interpretation, highlighting their strengths and limitations. In the recent decade, EVTF assays have been significantly developed. Among them, functional assays that use a blocking anti-TF antibody or immunocapture to measure EVTF activity have higher specificity and sensitivity than antigen assays. However, there is still a high variability between assays. Standardization and automatization are prerequisites for the measurement of EVTF in clinical laboratories.

Common structural features in some of the sequentially distant neurotransmitter transporters N-termini

The N-terminal regions of SLC6 transporters are sequentially unrelated, and the majority of such transporters contain only relatively short peptide N-terminal extensions. Currently, it is not clear if a diversity of N-terminal sequences represents diverse functions among the transporters or if there are common functions hidden behind similar, as yet unidentified, structures. Using alignment of amino acid sequences with the hydropathy plot, disorder prediction, and calpain recognition sites, we show that common structural features among the N-termini of some transporters might exist.We previously showed that polymeric neurotransmitter transporter N-termini exhibit very similar profiles of dynamic, time-dependent 465 nm-595 nm-750 nm absorbance metachromasia in the Bradford assay. Here we report that under certain mild denaturing conditions, filamentous aggregation of glutathione S-transferase (GST) protein results in similar near-infrared metachromasia. This effect was eliminated by further GST protein denaturation and solubilization. The results suggest that aggregation of partially denatured GST stabilizes Coomassie dye docking sites, producing a near-infrared absorbance shift similar to that observed in the polymeric unstructured N-termini of transporters.

Ultrasonic-microwave assisted extraction of selenium-rich rice bran protein: a study on its structural and physicochemical properties

This study explores the effects of different extraction methods on the physicochemical properties and functional performance of selenium-rich rice bran protein (Se-RBP). Four extraction techniques—alkaline extraction (AAE), microwave extraction (MAE), ultrasonic extraction (UAE), and ultrasonic-assisted microwave extraction (UMAE)—were assessed for their efficiency and impact on protein structure, solubility, and functional properties, including emulsifying and foaming capacities. The results demonstrate that UMAE significantly enhances the functional properties of Se-RBP, achieving an emulsion stability index of 86.76% and a foaming capacity of 188.63%, both of which outperform the other methods. Furthermore, UMAE-treated Se-RBP exhibited a 35.43% increase in selenium bioavailability following gastrointestinal digestion. UMAE also delivered the highest antioxidant activity, reducing the IC50 for DPPH radical scavenging to 0.85 mg/mL. These improvements are attributed to UMAE’s ability to achieve a finer, more uniform particle distribution and increased exposure of bioactive compounds. This study reveals the potential of UMAE in optimizing the extraction and functional utilization of Se-RBP.

Effect of microwave energy combined with hot air on the functional properties and antioxidant activity and pasting properties of Samh (Mesembryanthemum forsskalei Hochst) seeds

The study aimed to investigate the effect of microwave heating combined with hot air (70 °C) at different application times (0, 90 &180 s,) on the colour, digestible a soluble protein, functional and pasting properties, antioxidant capacity of Samh seeds (8, 12 & 16 % moisture content). The results indicated that microwave heating caused a significant change in Samh seed's colour and enhanced the protein solubility of the seeds, and the functional properties and viscosities of the Samh seeds. Moreover, the results showed that the moisture content of the Samh seeds and application time significantly impact the seeds' quality parameters. However, the partial least square (PLS) model validated that the microwave treatments of the samh seed with (16 %, 180 s) were treated with microwave energy combined with hot air circulation Accordingly, microwaves may offer the potential of being an effective emerging technology for improving the quality and functional characteristics of Samh seeds.

Physio-biochemical mechanism of melatonin seed priming in stimulating growth and drought tolerance in bread wheat

Drought stress (DS) adversely affects a plant’s development and growth by negatively altering the plant’s physio-biochemical functions. Previous investigations have illustrated that seed priming with growth regulators is an accessible, affordable, and effective practice to elevate a plant’s tolerance to drought stress. Melatonin (MT) is derived from the precursor tryptophan and can improve germination, biomass, and photosynthesis under stress conditions. The current study examined the effect of melatonin seed priming on two wheat cultivars (Fakhar-e-Bhakkar and Akber-19) cultivated under severe drought conditions (35% FC). There were 6 levels of melatonin (i.e., M0 = control, M1 = 1 mg L− 1, M2 = 2 mg L− 1, M3 = 3 mg L− 1, M4 = 4 mg L− 1 and M5 = mg L− 1) which were used for seed priming. Our results confirmed that seed priming with M2 = 2 mgL− 1 concentration of MT alleviates the negative effects of DS by boosting the germination rate by 54.84% in Akber-19 and 33.33% in Fakhar-e-Bhakkar. Similarly, leaf-relative water contents were enhanced by 22.38% and 13.28% in Akber-19 and Fakhar-e-Bhakkar, respectively. Melatonin pre-treatment with 2 mgL− 1 significantly enhanced fresh and dry biomass of shoot and root, leaf area, photosynthetic pigments, osmoprotectants accumulation [total soluble proteins (TSP), total free amino acids (TFAA), proline, soluble sugars, glycine betaine (GB)] and lowered the amount of malondialdehyde (MDA) and hydrogen peroxide (H2O2) production by elevating antioxidants [Ascorbic acid, catalase (CAT), Phenolics, peroxidase (POD) and superoxide dismutase (SOD)] activity under drought stress (DS). Meanwhile, under control conditions (NoDS), the melatonin treatment M1 = 1 mgL− 1 effectively enhanced all the growth-related physio-biochemical attributes in both wheat cultivars. In the future, more investigations are suggested on different crops under variable agroclimatic conditions to declare 2 mgL− 1 melatonin as an efficacious amendment to alleviate drought stress.

Separation of small extracellular vesicles (sEV) from human blood by Superose 6 size exclusion chromatography.

Extracellular vesicles (EVs) are valuable targets for liquid biopsy. However, attempts to introduce EV-based biomarkers into clinical practice have not been successful to the extent expected. One of the reasons for this failure is the lack of reliable methods for EV baseline purification from complex biofluids, such as cell-free plasma or serum. Because available one-step approaches for EV isolation are insufficient to purify EVs, the majority of studies on clinical samples were performed either on a mixture of EVs and lipoproteins, whilst the real number of EVs and their individual specific biomarker content remained elusive, or on a low number of samples of sufficient volume to allow elaborate 2-step EV separation by size and density, resulting in a high purity but utmost low recovery. Here we introduce Fast Protein Liquid Chromatography (FPLC) using Superose 6 as a matrix to obtain small EVs from biofluids that are almost free of soluble proteins and lipoproteins. Along with theestimation of a realistic number of small EVs in human samples, we show temporal resolution of the effect of theduration of postprandial phase on the proportion of lipoproteins in purified EVs, suggesting acceptable time frames additionally to the recommendation to use fasting samples for human studies. Furthermore, we assessed a potential value of pure EVs for liquid biopsy, exemplarily examining EV- and tumour-biomarkers in pure FPLC-derived fractions isolated from the serum of patients with pancreatic cancer. Consistent among different techniques, showed the presence of diseases-associated biomarkers in pure EVs, supporting the feasibility of using single-vesicle analysis for liquid biopsy.

Role of Hypoxic Secretome from Mesenchymal Stem Cells in Enhancing Tissue Repair: Regulatory Effects on HIF-1α, VEGF, and Fibroblast in a Sphincterotomy Rat Model.

Fecal incontinence (FI) is the inability to control bowel movements, resulting in fecal leakage. If left untreated, FI can seriously impact the long-term well-being of individuals affected. Recently, using secretome has become a promising new treatment method. The secretome combines growth factors released outside cells during stem cell development, such as mesenchymal stem cells. It consists of soluble proteins, nucleic acids, fats, and extracellular vesicles, which contribute to different cell processes. The primary aim is to assess the impact of hypoxic secretome administration on accelerating wound healing through the HIF-1α pathway in a post-sphincterotomy rat model. The study was conducted with two distinct groups of 10 rats each, the control and treatment groups, which were injected with hypoxic secretome at 0.3 mL. The inclusion criteria for the rats were as follows: male gender, belonging to the Sprague-Dawley strain, aged between 12 to 16weeks, with an average body weight ranging from 240 to 250 grams. There was an increase in HIF-1α gene expression in both groups. The treatment group 37 was significantly higher on day 42 (p = 0.001). VEGF increased significantly in the treatment 38 group on day 42 (p = 0.015). The neovascularization score increased significantly in the treatment 39 group during the first 24hours (p = 0.004). The fibroblast score increased significantly in the 40 treatment group in the first 24hours (p = 0.000) and 42 days (p = 0.035). After being given secretome, there was a higher increase in % collagen area and collagen area (µm2) in the treatment group compared to the control group (27,77 vs 11.01) and (419.027,66 vs 186.694,16). The use of hypoxic secretome has a significant effect as a choice for the treatment of anal sphincter injury after sphincterotomy through the HIF-1α-VEGF-Fibroblast pathway.

Changes in composition and concentration of differential metabolites in root exudates are associated with aluminum-tolerance of Ricinus communis under a high CO2 environment

Root exudates are the most direct performance for plants responding to adverse environments, and are also important media for materials exchange, energy transmission and information communication between the roots and rhizosphere. However, how plant roots and exudates respond to aluminum (Al) stress under elevated CO2 concentration (eCO2) is still unclear. Ricinus communis is a famous oilseed crop throughout the world, which has strong tolerance to metal contaminated soil. In the present study, root physiological changes and the exudates of this species under aluminum stress and eCO2 based on metabolomic were investigated. The results showed that high Al concentration stress significantly increased aluminum, MDA, proline, and soluble sugar contents, and decreased the dry weights and soluble protein concentration. Furthermore, eCO2 alleviated the inhibition of root growth under high Al stress by increasing the dry weights, antioxidant enzyme activities and decreasing the MDA content. Collectively, a total of 511 metabolites were detected in the castor exudates of which lipids, organic acids, and organic oxygen compounds occupied 40.82%, 17.78% and 12.54%, respectively. There were 83, 15, and 100 differential metabolites for high Al stress, eCO2 and the interaction of the two factors compared with the control. 12 differential metabolites were found under eCO2 and Al stress compared with Al stress alone. Under Al stress, TCA cycle, organic acids, and lipids metabolisms were inhibited; coumarins and carbohydrates conjugates were significantly up-regulated, which may help castor adapt to aluminum-contaminated conditions. Moreover, eCO2 increased the secretion of organic acids, fatty acyls, and carbohydrates to enhance the antioxidant capacity and root growth of castor under Al stress; eCO2 enhanced the TCA cycle, organic acids accumulation, lipids metabolism, biosynthesis of amino acids, pentose and glucuronate interconversions, and inhibited DNA oxidative stress of castor roots under Al stress. The present study provides new insights into the crucial role of root exudates in improving Al-tolerance of castor under eCO2.

WITHDRAWN: Enhancing Maize Growth Under Drought and Lead Stress with Deashed Biochar and Growth-Promoting Rhizobacteria

The agricultural sector faces significant challenges due to water scarcity and increasing lead (Pb) contamination, adversely affecting crop productivity by generating reactive oxygen species (ROS) during Pb stress and drought. Biochar and plant growth-promoting rhizobacteria (PGPR) are emerging as effective tools to manage oxidative stress, yet the combined use of deashed biochar (BC) and PGPR remains underexplored. This study aimed to investigate the synergistic effects of BC and Agrobacterium fabrum on maize growth and biochemical attributes. Two levels of BC (control and 0.5%) were applied with and without A. fabrum under no Pb stress (0 mg Pb/kg soil) and 400 mg Pb/kg soil stress conditions. Additionally, seeds inoculated with A. fabrum were subjected to no drought stress (65% field capacity w/v) and drought stress (40% field capacity w/v). Conducted with three replicates in a randomized design within controlled greenhouse conditions, the study demonstrated that BC+A. fabrum treatment significantly improved maize germination (53.33%), shoot length (69.32%), root length (11.76%), and total soluble protein content (32.36%) under 400 mg Pb/kg soil stress compared to controls. Furthermore, BC+A. fabrum effectively mitigated drought stress, enhancing chlorophyll a (55.02%), chlorophyll b (50.61%), and total chlorophyll (53.37%) levels compared to controls. Analysis of key antioxidants (peroxidase, superoxide dismutase, catalase, and ascorbate peroxidase) revealed BC+A. fabrum ability to modulate antioxidant defenses in maize, underscoring its potential as a sustainable strategy to enhance maize growth resilience under combined Pb and drought stress conditions. Future studies should explore the long-term effects and field applicability of BC+A. fabrum treatments to optimize agricultural sustainability and productivity in Pb-contaminated and drought-prone environments.

Salinity-Induced Photorespiration in Populus Vascular Tissues Facilitate Nitrogen Reallocation.

Adaptation to abiotic stress is critical for the survival of perennial tree species. Salinity affects plant growth and productivity by interfering with major biosynthetic processes. Detrimental effects of salinity may vary between different plant tissues and cell types. However, spatial molecular mechanisms controlling plant responses to salinity stress are not yet thoroughly understood in perennial trees. We used laser capture microdissection in clones of Populus tremula x alba to isolate palisade and vascular cells of intermediary leaf from plants exposed to 150 mM NaCl for 10 days, followed by a recovery period. Cell-specific changes in proteins and metabolites were determined. Salinity induced a vascular-specific accumulation of proteins associated with photorespiration, and the accumulation of serine, 3-phosphoglycerate and NH4 + suggesting changes in N metabolism. Accumulation of the GLUTAMINE SYNTHETASE 2 protein, and increased GS1.1 gene expression, indicated that NH4 + produced in photorespiration was assimilated to glutamine, the main amino acid translocated in Populus trees. Further analysis of total soluble proteins in stems and roots showed the accumulation of bark storage proteins induced by the salinity treatments. Collectively, our results suggest that the salt-induced photorespiration in vascular cells mediates N-reallocation in Populus, an essential process for the adaptation of trees to adverse conditions.

The Marine-Origin Exopolysaccharide-Producing Bacteria Micrococcus Antarcticus HZ Inhibits Pb Uptake in Pakchoi (Brassica chinensis L.) and Affects Rhizosphere Microbial Communities.

Exopolysaccharides (EPSs) produced by microorganisms play an important role in biotolerance and reducing heavy metal (HM) contamination by limiting the migration of HMs into plants. However, research on the application of EPS-producing marine bacteria for soil heavy metal remediation remains limited, particularly regarding their mechanisms of HM immobilization in soil and impact on plant growth. In this study, the EPS-producing marine bacterium Micrococcus antarcticus HZ was investigated for its ability to immobilize Pb and produce EPSs in soil filtrate. The effects on the growth quality and biomass of pakchoi (Brassica chinensis L.), as well as bacterial communities in inter-root soil contaminated with Pb, were also investigated. The results indicated that HZ could reduce the Pb concentration in the soil filtrate, achieving a removal rate of 43.25-63.5%. The EPS content and pH levels increased in the presence of Pb. Pot experiments showed that adding HZ significantly increased the biomass of pakchoi (9.45-14.69%), vitamin C (Vc) (9.69-12.92%), and soluble protein content (22.58-49.7%). HZ reduced the Pb content in the roots (17.52-47.48%) and leaves (edible tissues) (43.82-52.83%) of pakchoi. HZ increased soil enzyme activities (alkaline phosphatase, dehydrogenase, and urease), and the contents of ammonium nitrogen and nitrate nitrogen. Additionally, HZ also increased the relative abundance of beneficial bacteria (e.g., Proteobacteria, Cyanobacteria, and Chlorobacteria) in the inter-root soil, which have prophylactic and heavy-metal fixation functions. In summary, HZ reduces effective Pb content in edible tissues, roots, and inter-root soil by regulating inter-root soil microbial community structure, increasing soil pH, nitrogen content, and soil enzyme activity, and altering dominant phylum abundance.

Structural profiles of the full phagocyte NADPH oxidase unveiled by combining computational biology and experimental knowledge

The phagocyte NADPH oxidase (NOX2) is an enzyme, crucial for innate immune defense, producing reactive oxygen species necessary for pathogen destruction. Its activation requires the assembly of soluble proteins (p47phox, p40phox, p67phox, and Rac) with the membrane-bound flavocytochrome b558 (cytb558). We combined circular-dichroism analyses, with decades of experimental data, to filter structural models of the NADPH oxidase complex generated by the artificial intelligence program AlphaFold2 (AF2). The predicted patterns tend to closely resemble the active states of the proteins, as shown by the compact structure of the cytb558, whose dehydrogenase domain is stabilized closer to the membrane. The modeling of the interaction of p47phox with cytb558, which is the initial assembly and activation steps of the NADPH oxidase, enables us to describe how the C-terminus of p47phox interacts with the cytb558. Combining the AF2 cytb558 -p47phox model and its classical molecular dynamics simulations, we highlighted new hydrophobic lipid insertions of p47phox, particularly at residues Trp80-Phe81 of its PX domain. The AF2 models also revealed the implications of intrinsically disordered regions, such as the fragment between the PX domain and the SH3 regions of p47phox, in ensuring distant protein-protein and membrane-protein interactions. Finally, the AF2 prediction of the cytb558-Trimera model highlighted the importance of leaving Rac1 as a separate protein to reach an active state of the NADPH oxidase complex. Altogether, our step-by-step approach provides a structural model of the active complex showing how disordered regions and specific lipid and protein interactions can enable and stabilize the multi-subunit assembly.

Sustainable fungi-based protein extraction from agro-waste mushroom stem using deep eutectic solvents

This study evaluated the nutritional and functional qualities of the mushroom stem (MS) powder and its protein concentrates, which were extracted using alkaline and deep eutectic solvent (DES)-based methods. MS powder is rich in protein (23.02 %) and carbohydrates (63.01 %). Alkaline extraction yielded the highest protein content (45.90 %) but lower recovery rates (15.39 %) compared to DES extractions using a 1:2 M ratio of choline chloride: glycerol (DES-CG) and choline chloride: lactic acid (DES-CL), which had recovery rates of 22.04 % and 21.47 %, respectively. DES solvents provided strong hydrogen bonding, as indicated by FTIR analysis, and produced uniform, smooth particles according to SEM imaging. Both DES and alkaline methods achieved similar protein solubility values (72–75 %). However, DES methods better preserved emulsion capabilities and balanced foaming properties, enhancing foam capacity and maintaining stability. The findings suggest that DES methods are more sustainable and efficient for extracting proteins from MS powder, optimizing both functional properties and environmental sustainability in food applications.

Modulating the techno-functional properties of quinoa (Chenopodium quinoa Wild) protein concentrate using high-pressure technologies and their impact on in vitro digestibility: A comparative study

High hydrostatic pressure (HHP; 200–600 MPa at 24 °C for 20 min) and dynamic high pressure (DHP; 50–180 MPa) were applied to modulate the techno-functional properties of quinoa protein concentrate (QPC) produced from non-defatted flour using a lab-scale extraction. QPC's unique composition, with 74.6 % protein and significant levels of unsaturated fatty acids, influenced the effects of HHP and DHP. HHP significantly (P < 0.05) enhanced hydration properties, peaking at 400 and 500 MPa (on average 4.34 g/g), while DHP reduced the oil absorption capacity from 2.5 to 1.8 g/g. Both processing techniques decreased QPC protein solubility. This reduction corresponded to decreased foaming capacity and emulsifying properties in HHP-processed QPC. DHP increased emulsifying activity and stability indices, with optimized improvements at 100 MPa of 39.4 and 414.4 %, respectively. These modifications in QPC's properties occurred without noticeable loss in in vitro protein digestibility (IVPDaverage = 86.1 %). The findings support the potential of high-pressure technologies to uniquely modulate different techno-functional properties of QPC, produced from non-defatted flour, while maintaining high digestibility, thereby offering greater versatility in its use. Industrial relevanceQuinoa is a strategic choice for diversifying plant protein sources, with the use of non-defatted flour in QPC production offering new insights into its composition and properties, reducing both costs and environmental impact. In this study, HHP and DHP, recognized as “green” physical processing technologies, demonstrated advantageous potential to develop innovative quinoa protein ingredients with added value and clean-label appeal, while maintaining their high nutritional value. The distinctive effects of high-pressure technologies and varying pressure levels on modulating QPC's techno-functional properties underscore the creation of multifunctional QPC and the optimization of key properties, addressing the urgent demands of the plant-based food segment.

Polysaccharide-potato protein coacervates for enhanced anthocyanin bioavailability and stability

Anthocyanins (ACNs) possess strong antioxidants, anti-cancer, anti-obesity, anti-diabetic, and anti-inflammatory properties but are limited use by their susceptibility to environmental factors. This study aims to overcome these limitations by developing and assessing a novel coacervate system, consisting of potato protein isolate (PPI) combined with various polysaccharides, to stabilize and encapsulate anthocyanins from black carrot concentrate The polysaccharides included in this system include inulin, gum Arabic, guar gum, pectin, and soluble fiber. The coacervate system's effectiveness in maintaining stability and increasing the bioavailability of anthocyanins was evaluated compared to conventional soybean protein-based systems. The results show that pH considerably influences potato protein solubility, with maximum solubility at strongly acidic (pH 2) conditions. Hygroscopicity and moisture content analysis of the coacervates showed significant variations, with potato protein-guar gum (PPIGG) microcapsules having the lowest moisture content and potato protein gum Arabic (PPIGA) microcapsules having the highest moisture content. SEM imaging illustrated distinct microcapsule morphologies, while FT-IR measurement verified the successful integration of proteins and polysaccharides. The significance of the research reflects its proof that potato protein isolate (PPI) based coacervate systems consists of potato protein with polysaccharides, particularly those containing gum Arabic and pectin, have significant potential for improving anthocyanin stability and bioavailability. These findings guide future studies to investigate other polysaccharides, improve coacervation processes, and explore applications in the food and nutraceutical sectors. It also offers valuable insights for creating efficient encapsulation techniques for bioactive substances.

Co-fermentation of hot-pressed rapeseed meal with multiple strains and cellulase: Evaluating changes in protein quality and metabolite profiles

Hot-pressed rapeseed meal (RSM) is rich in resources, but high fiber content and low protein utilization result from high temperature processing. This study aims to obtain a high-quality protein source through the fermentation of hot-pressed RSM. We used Plackett-Burman and Box-Behnken designs to optimize parameters for solid state fermentation with Bacillus subtilis strain 5, Saccharomyces cerevisiae, and Aspergillus niger. Under the optimum conditions, the synergistic fermentation with multiple strains and cellulase significantly reduced anti-nutritional factors in hot-pressed RSM, while also increasing protein solubility, digestibility and extraction rate by 466.80%, 45.56% and 816.44%, respectively. 77 enzymes secreted by fermentation strains were identified in fermented hot-pressed RSM, which were mainly involved in the metabolism of proteins, peptides and amino acids (28.6%), energy (28.5%), carbohydrates (13.0%) and lipids (5.2%). Non-targeted metabonomics identified 1245 differential metabolites, with the top five being peptides and amino acids, lipids, heterocyclic compounds, alkaloids, and organic acids. These differential metabolites enhanced the nutritional, functional and flavor properties of fermented hot-pressed RSM. Among them, 702 differential metabolites were enriched into metabolic pathways, with the largest number of pathways associated with amino acid metabolism. These results hold important implications for understanding the quality of fermented hot pressed RSM.

Aggrescan4D: A comprehensive tool for pH-dependent analysis and engineering of protein aggregation propensity.

Aggrescan4D (A4D) is an advanced computational tool designed for predicting protein aggregation, leveraging structural information and the influence of pH. Building upon its predecessor, Aggrescan3D (A3D), A4D has undergone numerous enhancements aimed at assisting the improvement of protein solubility. This manuscript reviews A4D's updated functionalities and explains the fundamental principles behind its pH-dependent calculations. Additionally, it presents an antibody case study to evaluate its performance in comparison with other structure-based predictors. Notably, A4D integrates advanced protein engineering protocols with pH-dependent calculations, enhancing its utility in advising solubility-enhancing mutations. A4D considers the impact of structural flexibility on aggregation propensities, and includes a large set of precalculated predictions. These capabilities should help to open new avenues for both understanding and managing protein aggregation. A4D is accessible through a dedicated web server at https://biocomp.chem.uw.edu.pl/a4d/.

Differences in Physicochemical Properties of Stems in Oat (Avena sativa L.) Varieties with Distinct Lodging Resistance and Their Regulation of Lodging at Different Planting Densities.

Planting density is an effective strategy for regulating both oat lodging and forage quality. To delve into the regulatory mechanisms of planting density on lodging and oat forage quality, lodging-resistant variety LENA and lodging-sensitive variety QY2 were grown in 2018 and 2019 growing seasons, and four planting densities were implemented: 2.25 × 106 plants/ha (D1), 4.5 × 106 plants/ha (D2), 6.75 × 106 plants/ha (D3), and 9 × 106 plants/ha (D4). At the milk stage, we measured the contents of potassium, calcium, magnesium, silicon, lignin, crude fiber, starch, soluble sugar, and soluble protein in the second and third stem internodes of the plants. The results revealed the lodging-resistant variety LENA demonstrated significantly higher contents of calcium, potassium, silicon, crude fiber, lignin, and lower contents of starch, soluble sugar, and soluble protein (p < 0.01). Similar trends in the physicochemical properties of stem internodes for both oat varieties with increasing planting density. Crude fiber, soluble sugar, magnesium, starch, potassium, and lignin were the key characteristics affecting the lodging coefficient, and variety and planting density affected the lodging coefficient mainly by regulating the synthesis of starch, soluble sugar, and crude fiber. At planting density D3, stem internodes exhibited higher physicochemical properties and a lower lodging coefficient, favoring oat forage production. The results offer a valuable theoretical foundation and practical reference for oat lodging-resistant cultivation.