Protein Peptide Research Articles

Condensation of Soy Protein Peptides Contributes to Sequester Bile Acids and Mitigate LPS-Induced Inflammation.

Soy protein is widely known to have serum triglyceride (TG) and cholesterol-lowering effects associated with a reduced risk of cardiovascular disease. Recent studies highlighted that the extension region (ER) domain of soy 7S globulin (β-conglycinin) is a key component responsible for the serum TG-lowering effect via modulation of bile acid (BA) homeostasis. Here, we studied the sequestration of BAs by ER peptides during intestinal digestion in vitro and assessed the anti-inflammatory effects of ER peptides using Caco-2/HT29-MTX/RAW264.7 triple-cell cocultures as an intestine cell model. Results show that ER peptides, which share characteristics of intrinsically disordered regions (IDRs), are capable of forming peptide condensates and exhibit the capability to sequester BA-containing colloidal structures during intestinal digestion in vitro. Moreover, BAs enhance the penetration of peptide condensates within the mucus layer, enabling ER peptides to mitigate lipopolysaccharide (LPS)-induced gut inflammation. These results provide a possible explanation for the molecular mechanisms underlying the modulation of BA homeostasis by soybean proteins.

The small protein MntS evolved from a signal peptide and acquired a novel function regulating manganese homeostasis in Escherichia coli.

Small proteins (<50 amino acids) are emerging as ubiquitous and important regulators in organisms ranging from bacteria to humans, where they commonly bind to and regulate larger proteins during stress responses. However, fundamental aspects of small proteins, such as their molecular mechanism of action, downregulation after they are no longer needed, and their evolutionary provenance, are poorly understood. Here, we show that the MntS small protein involved in manganese (Mn) homeostasis binds and inhibits the MntP Mn transporter. Mn is crucial for bacterial survival in stressful environments but is toxic in excess. Thus, Mn transport is tightly controlled at multiple levels to maintain optimal Mn levels. The small protein MntS adds a new level of regulation for Mn transporters, beyond the known transcriptional and post-transcriptional control. We also found that MntS binds to itself in the presence of Mn, providing a possible mechanism of downregulating MntS activity to terminate its inhibition of MntP Mn export. MntS is homologous to the signal peptide of SitA, the periplasmic metal-binding subunit of a Mn importer. Remarkably, the homologous signal peptide regions can substitute for MntS, demonstrating a functional relationship between MntS and these signal peptides. Conserved gene neighborhoods support that MntS evolved from the signal peptide of an ancestral SitA protein, acquiring a life of its own with a distinct function in Mn homeostasis.

Antibody response to mycobacterial Rpf B protein and its immunodominant peptides in HIV-TB co-infected individuals

Diagnosis of TB at early stages of HIV infection may lead to timely intervention for improving patient outcome. Antibodies to Mycobacterium tuberculosis recombinant RpfB protein and two immunodominant peptides of Rpf B protein were evaluated in the sera of HIV +TB+, HIV+ and HIV− pulmonary TB patients by ELISA. Serum antibodies from 90 % and 65 % of HIV+TB+ patients reacted to recombinant RpfB protein and synthetic peptide RpfP1 respectively. Overall, this study shows that resuscitation promoting factor B elicits humoral antibody response in HIV+TB+ co-infected individuals and be proposed as a potential biomarker for diagnosis of HIV+TB+ patients, however further longitudinal follow up studies are warranted.

TIMP-1 in the prognosis of patients who underwent coronary artery bypass surgery: a 12-year follow-up study.

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been linked to clinical outcomes in patients with coronary artery disease (CAD). However, the prognostic value of TIMP-1 in patients with CAD who underwent coronary artery bypass grafting (CABG) has not been elucidated. We aimed to investigate the correlations of TIMP-1 with high-sensitivity C-reactive protein (hs-CRP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in the long-term prognosis of consecutive patients who underwent CABG. A total of 234 patients (age: 70.4 ± 10.5 years, 84.6% men) with CAD who underwent CABG were prospectively enrolled. Preoperative levels of MMPs, TIMP-1, hs-CRP, and NT-proBNP were recorded. Major adverse cardiovascular events (MACE) were defined as non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death. During a median follow-up of 12.1 years, 120 deaths were recorded. The deceased were older, had more manifest acute coronary syndrome (ACS), a lower left ventricular ejection fraction (LVEF), and an estimated glomerular filtration rate (eGFR), but significantly higher MMP13, TIMP-1, hs-CRP, and NT-proBNP compared with the survivors. After adjusting for age, sex, manifest ACS, eGFR, LVEF, total cholesterol, and triglycerides, TIMP-1 (hazard ratio and 95% confidence intervals per SD: 1.506, 1.183-1.917), hs-CRP (1.349, 1.183-1.561), and NT-ProBNP (1.707, 1.326-2.199) were all independently associated with all-cause mortality. The mediation analysis revealed that the mortality risks of TIMP-1 were partially mediated by NT-proBNP (62.2%) and hs-CRP (25.3%). The associations of TIMP-1 with MACE were partially mediated by NT-proBNP (54.4%) but not hs-CRP. TIMP-1 was an independent predictor of long-term outcomes after CABG, with possible roles in subclinical inflammation and postoperative cardiac remodeling.

Understanding Hyperuricemia: Pathogenesis, Potential Therapeutic Role of Bioactive Peptides, and Assessing Bioactive Peptide Advantages and Challenges.

Hyperuricemia is a medical condition characterized by an elevated level of serum uric acid, closely associated with other metabolic disorders, and its global incidence rate is increasing. Increased synthesis or decreased excretion of uric acid can lead to hyperuricemia. Protein peptides from various food sources have demonstrated potential in treating hyperuricemia, including marine organisms, ovalbumin, milk, nuts, rice, legumes, mushrooms, and protein-rich processing by-products. Through in vitro experiments and the establishment of cell or animal models, it has been proven that these peptides exhibit anti-hyperuricemia biological activities by inhibiting xanthine oxidase activity, downregulating key enzymes in purine metabolism, regulating the expression level of uric acid transporters, and restoring the composition of the intestinal flora. Protein peptides derived from food offer advantages such as a wide range of sources, significant therapeutic benefits, and minimal adverse effects. However, they also face challenges in terms of commercialization. The findings of this review contribute to a better understanding of hyperuricemia and peptides with hyperuricemia-alleviating activity. Furthermore, they provide a theoretical reference for developing new functional foods suitable for individuals with hyperuricemia.

Rapid detection of heat stress biomarkers in Atlantic salmon (Salmo salar) liver using targeted proteomics

AbstractMost fish are ectothermic; therefore, their physiology is significantly affected by temperature. Aquaculture fish have limited ability to avoid elevated water temperatures, with impacts increasing as a result of climate change. To date, quantifying gene expression has been proposed to monitor heat stress in salmon liver. This study aimed to establish a faster multiplexed proteomics method to measure the abundance of thermal stress biomarkers in liver of salmon reared at 15°C or 20°C. Moreover, this study aimed to determine the effects that sample pooling, and data normalisation using housekeeping (HK) protein peptides would exert over the statistical significance of these thermal stress markers. A multiple reaction monitoring (MRM) mass spectrometry method, comprised 45 peptides derived from thermal stress markers and 10 peptides from HK proteins, was applied to measure these markers in liver of salmon reared at 15°C or 20°C. When samples were processed individually, 34 peptides were significant between salmon livers at 15°C or 20°C. In pooled samples, this decreased to five significant peptides. Peptides hprt1_HYADDLDR (hypoxanthine phosphoribosyl transferase) and gapdh_VPTPNVSVVDLTVR (glyceraldehyde‐3‐phosphate dehydrogenase) were the most stable and unstable HK protein peptides, respectively. When data was normalised with hprt1_HYADDLDR, 16 peptides were significant in individual samples and 13 in pooled samples. Significant peptides serpinh1a_ADLSNISGK, SerpinH1_TNSILFIGR, ela2_VVGGEDVR and gapdh_VPTPNVSVVDLTVR were common regardless of data strategy. A fast and reliable MRM method was established to validate thermal stress markers in salmon liver, where individual samples yielded better results than pooled samples. Sample pooling was only better when combined with normalisation as it validated twice the number of markers than sample pooling alone. This method could be applied to monitoring stress response in experiments involving feeding additives designed to mitigate thermal stress or in selective breeding programs to help understanding family variance in thermal tolerance.

Prediction of interface between regions of varying degrees of order or disorderness in intrinsically disordered proteins from dihedral angles

Intrinsically disordered proteins (IDPs) are proteins that do not form uniquely defined three-dimensional (3-D) structures. Experimental research on IDPs is difficult since they go against the traditional protein structure-function paradigm. Although there are several predictors of disorder based on amino acid sequences, but very limited based on the 3-D structures of proteins. Dihedral angles have a significant role in predicting protein structure because they establish a protein’s backbone, which, coupled with its side chain, establishes its overall shape. Here, we have carried out atomistic Molecular Dynamics (MD) simulations on four different proteins: one ordered protein (Monellin), two partially disordered proteins (p53-TAD and Amyloid beta (Aβ1-42) peptide), and one completely disordered protein (Histatin 5). The MD simulation trajectories for the corresponding four proteins were used to conduct dihedral angle (ϕ and ѱ) analysis. Then, the average dihedral angles for each of the residues were calculated and plotted against the residue index. We noticed steep rises or falls in the average ϕ value at certain locations in the plot. These sudden shifts in the average ϕ value reflect the interface between regions of varying degrees of order or disorderness in intrinsically disordered proteins. Using this method, the probable conformer of a protein with a higher degree of disorder can be found among the ensembles of structures sampled during the MD simulations. The results of our study offer new understandings on precisely identifying regions of various degrees of disorder in intrinsically disordered proteins. Communicated by Ramaswamy H. Sarma

Comparison of methods for the detection of porcine cytomegalovirus/roseolovirus in relation to biosafety monitoring of xenotransplantation products

AbstractBackgroundThe porcine cytomegalovirus, a porcine roseolovirus (PCMV/PRV), is widely distributed in pig populations. It has been shown that PCMV/PRV was transmitted by pig xenotransplants to non‐human primates, and significantly reduced the survival time of the recipient. PCMV/PRV was also transmitted during the first transplantation of a pig heart into a human patient. PCMV/PRV establishes a lifelong persistent infection (latency) in the host, is difficult to detect in this stage, and consequential poses a threat to future clinical xenotransplantations. Therefore, sensitive and specific methods and goal‐oriented strategies how, when, and where to test should be used for screening donor pigs.MethodsIn this study we compared experimentally the PCMV/PRV detection methods including PCR‐based (real‐time PCR, nested PCR) and immunological methods (Western blot assay, ELISA) recently published by Halecker et al. (Sci. Rep. 2022;12(1):21545) and Fischer et al. (Xenotransplantation 2023:e12803). We also compared the antigens used for antibody detection (a recombinant protein and synthetic peptides corresponding to a conserved region of the glycoprotein B, gB).ResultsThe published methods can be used for screening donor pigs, with the results being similar. The antigens used for the detection of PCMV/PRV‐specific antibodies are almost identical and give comparable results. Overall, the optimal diagnostic tests, the samples used for testing and the time of sampling play a crucial role in preventing the transmission of PCMV/PRV during xenotransplantation.ConclusionSensitive methods are available to screen donor pigs for PCMV/PRV, but a rational application of a combination of PCR‐based and immunological methods as well as rational detection strategies are important for the detection of the virus during latency.

Superior antibody and membrane protein-specific T-cell responses to CoronaVac by intradermal versus intramuscular routes in adolescents

BackgroundOptimising the immunogenicity of COVID-19 vaccines to improve their protection against disease is necessary. Fractional dosing by intradermal (ID) administration has been shown to be equally immunogenic as intramuscular (IM) administration for several vaccines, but the immunogenicity of ID inactivated whole severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the full dose is unknown. This study (NCT04800133) investigated the superiority of antibody and T-cell responses of full-dose CoronaVac by ID over IM administration in adolescents.MethodsParticipants aged 11–17 years received two doses of IM or ID vaccine, followed by the 3rd dose 13–42 days later. Humoral and cellular immunogenicity outcomes were measured post-dose 2 (IM-CC versus ID-CC) and post-dose 3 (IM-CCC versus ID-CCC). Doses 2 and 3 were administered to 173 and 104 adolescents, respectively.ResultsSpike protein (S) immunoglobulin G (IgG), S-receptor-binding domain (RBD) IgG, S IgG Fcγ receptor IIIa (FcγRIIIa)-binding, SNM [sum of individual (S), nucleocapsid protein (N), and membrane protein (M) peptide pool]-specific interleukin-2 (IL-2)+CD4+, SNM-specific IL-2+CD8+, S-specific IL-2+CD8+, N-specific IL-2+CD4+, N-specific IL-2+CD8+ and M-specific IL-2+CD4+ responses fulfilled the superior and non-inferior criteria for ID-CC compared to IM-CC, whereas IgG avidity was inferior. For ID-CCC, S-RBD IgG, surrogate virus neutralisation test, 90% plaque reduction neutralisation titre (PRNT90), PRNT50, S IgG avidity, S IgG FcγRIIIa-binding, M-specific IL-2+CD4+, interferon-γ+CD8+ and IL-2+CD8+ responses were superior and non-inferior to IM-CCC. The estimated vaccine efficacies were 49%, 52%, 66% and 79% for IM-CC, ID-CC, IM-CCC and ID-CCC, respectively. The ID groups reported more local, mild adverse reactions.ConclusionThis is the first study to demonstrate superior antibody and M-specific T-cell responses by ID inactivated SARS-CoV-2 vaccination and serves as the basis for future research to improve the immunogenicity of inactivated vaccines.Graphical abstract

Insights into the potential toxicity of Zn(II) to catalase and their binding mechanisms

As a common metal, Zinc was widely used in the in the galvanising industry. However, the overuse had contributed to the environmental overexposure of zinc, which had caused a number of health issues in environmental organisms. Catalase (CAT) plays a critical part in regulating oxidative stress in the body of humans. Interactions between Zn(II) and CAT were examined in this paper using a variety of spectroscopic techniques, molecular docking, isothermal titration calorimetry (ITC) and enzyme activity assay. According to the results, Zn(II) can interact with CAT fluorophore residues like Trp and Tyr and demonstrate fluorescence sensitization to these amino acids. Direct contact between CAT and Zn(II) led to the disruption of protein backbone structure and peptide chain tightening. When exposed to Zn(II), the secondary structure of CAT was altered, including the decreased α-helix of CAT, increased β-sheet content, and the increased grain size of the zinc-CAT complex. Measurement of thermodynamic parameters of the binding reaction by ITC showed that the force between Zn(II) and CAT was electrostatic force. In addition, the binding site of Zn(II) is close to the active center of CAT which boosted enzyme activity. In conclusion, our research demonstrates that Zinc has an impact on both the structure and function of CAT.

Ultrasonographic study of hand joints erosions in rheumatoid arthritis: Relation to clinical characteristics, disease activity and functional status

BackgroundRheumatoid arthritis (RA) is a commonly diagnosed chronic inflammatory arthritis. Bone erosion can occur early during RA and is considered as an important predictor of a severe clinical course. Aim of the workTo assess ultrasound-detected bone erosions in RA patients and establish their associations with clinical and laboratory variables. Patients and methodsThis study included sixty RA patients. The dorsal and volar joint aspects of the wrist (midcarpal and radiocarpal joints), the first to the fifth metacarpophalangeal (MCP) and proximal interphalangeal joints were scanned in the long and short axes for synovial hypertrophy, tenosynovitis, and erosions. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), and anti-cyclic citrullinated peptide (anti-CCP) were performed. The disease activity score (DAS28) and health assessment questionnaire (HAQ) was evaluated ResultsThe mean age of the patients was 43 ± 11.04 years with median disease duration of 5 (0.1–20) years and there were 57 females. Forty-one patients had bone erosions and 19 did not. Erosions were most frequently found in the MCP joints (48.3 % of examined patients). There was no significant difference between the two groups regarding age (p = 0.36), gender (p = 1), RF (p = 0.4), and anti-CCP (p = 0.6). The bone erosion scores significantly correlated with swollen joint count (p = 0.001), tender joint count (p = 0.018), patient global health (p = 0.024), DAS28 (p = 0.003), HAQ (p = 0.032), ESR (p = 0.005), presence of synovitis (p = 0.005), and synovitis score (p < 0.001). ConclusionsThe US-detected bone erosions are predominant in RA, most frequently at the MCP joints, and are associated with disease activity, inflammatory markers, and synovitis.

Interdisciplinary gene manipulation, molecular cloning, and recombinant expression of modified human growth hormone isoform-1 in E. coli system

BackgroundGrowth hormone (GH) is a hormone that promotes growth, cell reproduction, and cell restoration in humans and animals. ObjectivesProduction of recombinant human growth hormone (rhGH) in Escherichia coli (E. coli) and assessment of its characteristics and proliferation stimulatory activity. MethodsThe hGH gene was cloned into a pET 3a expression vector and transformed into a competent E. coli cell. The refolded hGH was purified, Western blot and batch fermentation were performed. Cell cytotoxicity was tested on Vero cells, and MALDI-TOF and Nano-LC-ESI MS/MS were used for protein and target peptide analysis. ResultsInduced rhGH was purified with a concentration of 511.9 mg/ml. Western blot confirmed the molecular identity of rhGH, showing a single 22 kDa band. The bacterial growth at OD600 after 24 h in batch fermentation was 9.78 ± 0.26, and wet cell weight (WCWg/L) was 15.2 ± 0.32. Purified rhGH activity on Vero cells was 0.535 IU/mg. LC-MS/MS analysis revealed a score of 70.51 % and coverage of 60.37 %. ConclusionBiologically active native rhGH protein was successfully expressed in the Prokaryotic system. Our goal is to increase its production on a pilot level in the native form at a high activity effect identical to isoform 1.

Comparative studies on the chemical composition and pharmacological effects of vinegar-processed antler glue modified from Lei Gong Pao Zhi Lun and traditional water-processed antler glue

Ethnopharmacological relevanceAntler glue is a classic medicinal to enhance sexual function in traditional Chinese medicine (TCM), which was first recorded in Shen Nong Ben Cao Jing (Shennong′s Classic of the Materia Medica). Vinegar-processing is a classic method of processing traditional Chinese medicine. The method of preparing antler glue by boiling antlers in vinegar and then concentrating them is recorded in Lei Gong Pao Zhi Lun (Master Lei′s Discourse on Medicinal Processing). In modern times, the typical processing method of antler glue is water extraction and concentration. However, it is not clear whether there is a difference in the effect of these two processing methods on the chemical composition and pharmacological activity of antler glue. Aim of the studyThe Chinese Pharmacopoeia (2020) records that the processing method of antler glue is water extraction and concentration. But Lei Gong Pao Zhi Lun differs in Chinese Pharmacopoeia (2020), which records the processing method of vinegar extraction and concentration. The effect of the two processing methods on antler glue's chemical composition and pharmacological activity is unknown. So this study aimed to elucidate the difference between different processing methods on the chemical composition and the treatment effect on oligoasthenospermia of antler glue. Materials and methodsSo the automatic amino acid analyzer is used to determine the amino acid content of two different processing methods of antler glue. Proteomics was performed to detect the protein components of two different processing methods of antler glue and analyze them. Cyclophosphamide-induced mice models of oligoasthenospermia were used to study the different pharmacological effects of antler glue in two different processing methods. An automatic sperm analyzer observed the quantity and quality of sperm in mice epididymis. Serum sex hormone testosterone (T), luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels in mice were tested using the enzyme-linked immunosorbent assay (ELISA) kits. Hematoxylin-eosin (H&E) staining was used to analyze pathological alterations in mouse testicular tissue. The transcriptome has been used to reveal the potential mechanism of antler glue in treating oligoasthenospermia. Mitochondrial complex activity assay kits were used to assay the activity of mitochondrial respiratory chain complex I–V in mouse testicular tissue. Western blot was used to determine the expression of related proteins in mouse testicular tissue. ResultsVinegar-processing can increase the alanine, proline, and glycine content in antler glue, reduce the length of protein peptides in antler glue, and produce a variety of unique proteins. Vinegar-processed antler glue (VAG) increased sperm density, sperm survival, sperm viability, and serum sex hormone levels in oligozoospermic mice. It reversed testicular damage caused by cyclophosphamide, and the effects were differently superior to those of water-processed antler glue (WAG). In addition, transcriptomics and related experiments have shown that VAG can increase the expression of Ndufa2, Uqcr11, Cox6b1, and Atp5i genes and proteins in mouse testis, thus promoting adenosine diphosphate (ATP) synthesis by increasing the activity of mitochondrial respiratory chain complexes I, III, IV and V. By promoting the oxidative phosphorylation process to produce more ATP, VAG can achieve the therapeutic effect of oligoasthenospermia. ConclusionVinegar-processing method can increase the content of active ingredients in antler glue. VAG increases ATP levels in the testes by promoting the process of oxidative phosphorylation to treat oligozoospermia.

Development of a targeted proteomic assay for the quantitation of neurofilament light in cerebrospinal fluid: Correlation with Simoa‐based quantitation across neurodegenerative diseases and centres

AbstractBackgroundCerebrospinal fluid (CSF) neurofilament light (NfL) is a dynamic biomarker of neurodegeneration that is used for supporting clinical diagnosis and monitoring disease‐modifying therapies. Development of new analytical tests has been limited, with quantitation of NfL in biomarker studies largely restricted to immunoassay methods. Targeted mass spectrometry is a highly specific technique that can be easily translated into existing proteomic and clinical pathology laboratories. In this multi‐centre study, we have developed two targeted mass spectrometry assays which were compared to Simoa, the gold standard method for NfL quantitation. The developed methods included immunocapture of intact NfL protein or specific peptides (immune‐peptide capture) prior to targeted proteomic analyses. We discuss the development, validation and merits of each technology to quantitate NfL in CSF from healthy controls and several neurodegenerative diseases.MethodCSF was collected from patients with a range of neurological diseases at the National Hospital for Neurology and Neurosurgery (London, UK). Clinical diagnosis was determined by their treating clinician according to consensus clinical criteria. NfL concentrations were measured by Simoa (Quanterix, USA) and two immunoprecipitation‐targeted mass spectrometry (IP‐MS) assays developed by a collaboration between UCL and Washington University in St Louis. To evaluate replication of results across centres and mass spectrometry approaches, results were compared using Spearman’s correlation analysis and Bland‐Altman testing.ResultsA high correlation was observed for CSF NfL levels between Simoa and both IP‐MS assays (immune‐peptide capture, r = 0.90, P&lt;0.0001 and immune‐protein capture, r = 0.88, P&lt;0.0001). Relative differences in mean NfL concentration between clinical groups remained the same across the analytical methods, with the highest and lowest NfL concentrations observed in the Huntington’s disease and the healthy control groups respectively. Interestingly, differences in the extent of correlation between Simoa and IP‐MS were observed between the different clinical groups (r = 0.37 ‐ 0.94).ConclusionImmunoprecipitation‐targeted mass spectrometry quantitation of NfL correlates highly with NfL Simoa measures across a range of neurodegenerative and neuroinflammatory diseases, and is replicable between laboratories using different immunoprecipitation‐targeted mass spectrometry approaches.

Tea (Camellia sinensis (L.) Kuntze) as an emerging source of protein and bioactive peptides: A narrative review.

Tea residues represent one of the major agricultural wastes that are generated after the processing of tea. They account for 21-28% of crude protein and are often discarded without the extraction of valuable proteins. Due to various bioactivity and functional properties, tea proteins are an excellent alternative to other plant-based proteins for usage as food supplements at a higher dosage. Moreover, their good gelation capacity is ideal for the manufacturing of dairy products, jellies, condensation protein, gelatin gel, bread, etc. The current study is the first to comprehend various tea protein extraction methods and their amino acid profile. The preparation of tea protein bioactive peptides and hydrolysates are summarized. Several functional properties (solubility, foaming capacity, emulsification, water/oil absorption capacity) and bioactivities (antioxidant, antihypertensive, antidiabetic) of tea proteins are emphasized.

Active peptides with hypoglycemic effect obtained from hemp (Cannabis sativa L) protein through identification, molecular docking, and virtual screening.

Hemp (Cannabis sativa L) seeds are rich in proteins of high nutritional value, which makes the study of beneficial properties of hemp seed proteins and peptides, such as hypotensive and hypoglycemic effects, increasingly attractive. The present results confirm the good processability and stability of the hemp protein hydrolysate obtained by enzymatic hydrolysis of non-dehulled hemp seed meal (NDHM). Six peptides with potential hypoglycemic activity were obtained by ethanol-graded precipitation, Nano LC-Q-Orbitrap-MS/MS mass spectrometry, and computerized virtual screening. Further, validation experiments for in vitro synthesis showed that TGLGR, SPVI, FY, and FR exhibited good α-glucosidase inhibitory activity, respectively. Animal experiments showed that the hemp protein peptides modulated blood glucose and blood lipids in hyperglycemic rats. These results indicate that hemp protein peptides can reduce blood glucose levels in hyperglycemic rats, suggesting that hemp proteins may be a promising natural source for the prevention and treatment of hyperglycemia.

Omics‐Imaging Data Integration via Mediation Analysis with High‐Dimensional Exposures and Mediators

AbstractBackgroundMultimodal technologies have transformed AD research in recent years, by collecting different types of data from the same group of subjects and enabling the investigation of complex interrelated mechanisms underlying AD development.MethodIn this article, a mediation analysis approach with high‐dimensional exposures and high‐dimensional mediators is proposed to integrate data collected from multiple platforms. The proposed method combines principal component analysis with penalized least squares estimation for a set of linear structural equation models. The former reduces the dimensionality and produces uncorrelated linear combinations of the exposure variables, whereas the latter achieves simultaneous path selection and effect estimation while allowing the mediators to be correlated.ResultApplying the method to the AD data, it identifies numerous interesting protein peptides, brain regions, and protein‐structure‐memory paths, which are in accordance with and also supplement existing findings of AD research.ConclusionThe proposed approach is designed to integrate multiview data via a mediation framework. Under biological mechanistic assumptions, it articulates the underlying mechanisms and interrelations between data modalities and further infers disease pathology.

PepCNN deep learning tool for predicting peptide binding residues in proteins using sequence, structural, and language model features

Protein–peptide interactions play a crucial role in various cellular processes and are implicated in abnormal cellular behaviors leading to diseases such as cancer. Therefore, understanding these interactions is vital for both functional genomics and drug discovery efforts. Despite a significant increase in the availability of protein–peptide complexes, experimental methods for studying these interactions remain laborious, time-consuming, and expensive. Computational methods offer a complementary approach but often fall short in terms of prediction accuracy. To address these challenges, we introduce PepCNN, a deep learning-based prediction model that incorporates structural and sequence-based information from primary protein sequences. By utilizing a combination of half-sphere exposure, position specific scoring matrices from multiple-sequence alignment tool, and embedding from a pre-trained protein language model, PepCNN outperforms state-of-the-art methods in terms of specificity, precision, and AUC. The PepCNN software and datasets are publicly available at https://github.com/abelavit/PepCNN.git.

Preparation, structural characterization and functional properties of a novel selenium chelating peptide derived from the hydrolyzate of wheat protein

ABSTRACT Organic selenium has been widely studied for its ability to better fulfill the physiological functions of selenium. In this study, a novel organic selenium (wheat protein hydrolyzate chelated selenium, WPH-Se) was prepared by chelating the hydrolyzate of wheat protein hydrolyzed by alkaline protease (WPH) with selenium, its preparation process was optimized; and structural and functional properties were investigated. The results showed that the highest selenium content of 10.97 mg/g was obtained in the chelate under the optimal conditions (peptide/selenium mass ratio 2:1, temperature 80°C, pH 8, time 60 min). UV-Vis, FTIR, DSC and SEM provided more information for the characterization of WPH-Se. During the chelating process, selenium ions might be effectively bound to WPH through carboxyl, carbonyl and amino ligands, and the C=O bond and -NH, -OH groups might be the sites. At different pHs, the solubility of WPH-Se was generally lower than that of WPH, which reached a maximum of 32.69% at pH 6. The EAI of WPH-Se was higher than that of WPH, which reached a maximum of 0.84 m2/g, and the ESI reached a maximum of 47.3 min at pH 10. The free sulfhydryl content of WPH-Se was greater than that of WPH, which reached a maximum of 12.78 μmol/g at pH 8. WPH-Se was superior to WPH in terms of foaming ability and emulsification properties. WPH-Se contained a certain amount of aromatic amino acids (7.962%) and a relatively high amount of hydrophobic amino acids (38.490%), and had high nutritional value. Wheat protein peptide chelated selenium would be a useful functional additive, this study would provide data to support further research and application of selenium dietary supplements.

Effect of microbial fermentation on the quality of soybean meal

SummarySoybean meal is an important and inexpensive source of protein in food and animal feed, and contains anti‐nutritional factors such as trypsin inhibitors, antigenic proteins, oligosaccharides, phytic acids and lectins, which limit its application. Microbial fermentation has the capability to improve the nutritional value and biological activities of soybean meal by changing its natural composition. Fermentation results in the degradation of anti‐nutritional factors in soybean meal, an increased amount of small molecular protein peptides and improved content of isoflavone aglycone. However, the nutritional composition and biological activities of the resulting fermented products differ due to the different microbial species and conditions used for fermentation. Compared to soybean meal, fermented soybean meal has several beneficial effects such as digestibility, antioxidant and hypoallergenicity. The objective of this review is to discuss the fermentation processes of soybean meal, as well as outlines some biological activities associated with it. Furthermore, the current application of fermented soybean meal is also summarised.