Production Of Peptides Research Articles

Interpopulational Variation in Cyclotide Production in Heavy-Metal-Treated Pseudometallophyte (Viola tricolor L.)

It remains an open question whether violets use universal mechanisms, such as the production of metallothioneins, phytochelatins, and organic acids and/or rely on specific mechanisms like the production of antimicrobial cyclic peptides (cyclotides) for heavy metal tolerance. To contribute to the understanding of the role of cyclotides, we used seed-derived plants from metallicolous (M) and non-metallicolous (NM) populations of Viola tricolor, a pseudometallophyte tolerant to Zn and Pb. Eight- to ten-week-old plants were treated with 1000 μM of Zn or Pb for 3 or 7 days and subsequently measured for cyclotides and heavy metal content using MALDI-MS and Atomic Absorption Spectrometry (AAS), respectively. Individuals from the M population accumulated a similar amount of Zn but occasionally more Pb in comparison with the NM population. Of the 18 different cyclotides included in the analysis, some showed statistically significant changes under the heavy metal treatment. In general, a decrease was observed in the M population, whereas an increase was observed in the NM population (except for the 3-day treatment with Zn). The day of treatment and dose of metal and their interaction played a crucial role in the explained variance for cyclotides produced by the M individuals but not for the NM plants. This unravels the importance of this antimicrobial compound in heavy metal tolerance and indicates that, in V. tricolor, cyclotides are involved in heavy metal tolerance, but specimens from two populations have developed different strategies and tolerance mechanisms involving cyclotides to mitigate heavy metal stress.

Cost-Benefit Analysis of Enzymatic Hydrolysis Alternatives for Food Waste Management

In this study, we aimed to evaluate the economic, environmental, and social viability of the enzymatic hydrolysis process for food waste valorization by applying cost-benefit analysi (CBA). Our research was based on the investigation of three scenarios/alternatives for the final product of the enzymatic hydrolysis process and the production of bioethanol, bioactive peptides, and organic acids. Key economic indicators, such as cost/benefit ratios, net present value (NPV), and internal rate of return (IRR), were used to evaluate financial performance. At the end of the CBA, a sensitivity analysis was conducted to highlight the performance of each scenario under varying conditions, including fluctuating costs, benefits, and discount rates. These results indicate that enzymatic hydrolysis offers a significant opportunity for reducing food waste and its environmental impacts and promotes sustainability. Bioactive peptide production was found to be the most environmentally viable option, offering the highest cost-benefit efficiency. In both the optimistic and pessimistic scenarios of the sensitivity analysis, the results revealed that bioactive peptide production is economically viable, while the other alternatives, such as bioethanol and organic acid production, are more sensitive to economic and operational changes. This study revealed that enzymatic hydrolysis, as evaluated through CBA, offers a viable and impactful method for food waste management. It reduces environmental impacts, enhances sustainability, and aligns with the principles of a circular economy. The adoption of such innovative waste management strategies is considered essential for building a more sustainable and resource-efficient food system.

A comparative study on antidiabetic and anti-inflammatory activities of fermented whey and soy protein isolates and the release of biofunctional peptides: an in vitro and in silico studies.

This study aims to evaluate the antidiabetic and anti-inflammatory activities of Lacticaseibacillus rhamnosus (M9) MTCC 25516 during the fermentation of whey and soy protein isolates. It also seeks to characterize protein profiles, identify multifunctional peptides, and assess structural changes using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two-dimensional (2D) gel electrophoresis, Fourier-transform infrared (FTIR) spectroscopy, and confocal laser scanning microscopy (CLSM). Fermentation with Lacticaseibacillus rhamnosus (M9) significantly enhanced antidiabetic activity, with optimal peptide production at a 25 mL L-1 inoculation rate for 48 h at 37 °C. Proteolytic activity reduced inflammatory markers (IL-6, TNF-α, IL-1β, NO) in RAW 267.4 cells. SDS-PAGE and 2D gel electrophoresis revealed distinct protein profiles, with 19 and 49 protein spots in whey and soy isolates, respectively. Reverse-phase high-performance liquid chromatography (RP-HPLC) identified multifunctional peptides, and FTIR spectroscopy confirmed structural changes post-fermentation. Confocal microscopy further revealed protein modifications. Fermentation of whey and soy protein isolates with Lacticaseibacillus rhamnosus (M9) enhances antidiabetic and anti-inflammatory properties. Optimal conditions (25 mL L-1 inoculation, 48-h incubation) improved peptide production, with analytical techniques confirming structural and functional changes. These findings suggest fermented protein isolates could be valuable in functional foods with health benefits. © 2025 Society of Chemical Industry.

Production, characterization and bio-functional properties of multi-functional peptides from fermented plant-based foods: A review

Production, characterization and bio-functional properties of multi-functional peptides from fermented plant-based foods: A review

Impact of ultrasonic pretreatment on pumpkin seed protein: Effect on protease activities, protein structure, hydrolysis kinetics and functional properties.

Adding value to food by-products, such as pumpkin seeds, is an important strategy for the complete utilization of plant foods and advancing sustainability goals. This study aimed to maximize the production of bioactive peptides from pumpkin seed protein (PSP) by combining ultrasonic (US) pretreatment (40kHz, 23.8W/L) with enzymatic hydrolysis. The PSP's structure after sonication and its effects on the commercial proteases (Brauzyn®, Flavourzyme®, Neutrase®) activity and degree of hydrolysis were studied. The hydrolysis consequences regarding solubility and antioxidant activity of the resulting peptides were also evaluated. Sonication of PSP increased enzymatic activity by up to 21.3% for Brauzyn®, 24.8% for Flavourzyme® and 19.2% for Neutrase®. Consequently, there was an increase in the degree of hydrolysis (up to 89%) using sonicated PSP, particularly at 60min/40°C. These effects can be attributed to ultrasound-induced protein conformation changes, including increased intrinsic fluorescence intensity (<22%), shifts in UV spectra, and alterations in FTIR amide bands, especially a decrease in β-sheet content (<7.14%). Additionally, ultrasonic pretreatment reduced particle size (<43.9%) and polydispersity index (<58%), enhancing enzyme accessibility by fragmenting protein aggregates, as observed via scanning electron microscopy. As a result, the peptides obtained from the hydrolysis of sonicated PSP exhibited higher protein solubility (12% to 49% at pH 6.0) and improved antioxidant activity (5.6% to 77%). Overall, sonication of PSP for 60min at 40°C followed by hydrolysis with Neutrase® proved to be the most effective strategy for producing highly soluble peptides with enhanced antioxidant properties, highlighting the potential of ultrasound as a valuable tool for optimizing bioactive peptide production. Based on these results, the developed process is ready for scale-up by the food industry, aiming to obtain protein hydrolysates with improved functional and/or nutritional properties from a low-cost raw material. In parallel, further researches can focus on the potential application of these hydrolysates as ingredients in bakery, meet or dairy products.

Functional characterization and mechanism of the multidrug resistance transport potein YoeA in Bacillus subtilis.

Transport proteins are essential for bacterial resistance to antibiotics and toxins, but their mechanisms remain poorly understood in Bacillus subtilis. In the present study, overexpression of yoeA enhanced resistance to various antibiotics, with its expression induced by these antibiotics, especially penicillin and plipastatin. The ΔyoeA strain exhibited significant growth inhibition at 100μg/mL of plipastatin, while as high as 10,000μg/mL of iturin/surfactin are required to achieve comparable inhibition, suggesting a higher sensitivity of ΔyoeA to plipastatin. The transcript level of yoeA gene was increased 2.71-fold in response to plipastatin, significantly higher than the levels induced by surfactin and iturin. The ethidium bromide (EtBr) efflux activity of YoeA was inhibited by carbonyl cyanide chlorophenylhydrazone (CCCP) and enhanced by Na+. Molecular modeling studies revealed that cation-π interactions of Na+ with Y287 and Y434 residues in the C-terminal domain of YoeA contribute to its ion channel function, and Cu2+ can form coordination bonds with the N atoms of H278 and H421 residues on the C-terminal surface of YoeA, promoting plipastatin efflux in a dose-dependent manner. The present study characterized the main factors influencing YoeA's efflux activity, revealed its transport mechanism, and provided new insights into enhancing antimicrobial peptide production and controlling bacterial resistance.

The Impact of Thermal and pH Variations on the Structure of Cathepsin D in the Hepatopancreas of Japanese Clam (Ruditapes philippinarum).

Cathepsin D is a lysosomal enzyme that plays a critical role in the process of protein catabolism. In marine organisms, research has primarily concentrated on the identification of the enzyme. However, in crustaceans and molluscs, it is known to have digestive functions, as it is the sole enzyme responsible for protein degradation at extremely acidic pH in the hepatopancreas. In the Japanese clam (Ruditapes philippinarum), cathepsin D was purified and partially characterised by the hepatopancreas. To evaluate changes in secondary structure, circular dichroism (CD) was employed under a range of 5-70°C and pH of 1-7.5. Following dissection, the enzyme was purified from the hepatopancreas by ultrafiltration and affinity chromatography. SDS-PAGE was used to verify the sample purity, and gel filtration was used to determine the molecular weight.. CD spectra were obtained at a concentration of 0.125 mg/mL, expressed as mean ellipticity per residue. The purified cathepsin D demonstrated a specific activity of 5,553 ± 220 U/mg and a molecular weight of 36.5 kDa. The enzyme demonstrated optimal activity within a temperature range of 45-50°C and a pH range of 3-3.5. CD analyses demonstrated alterations in the secondary structure at elevated temperatures and pH fluctuations, which were correlated with a reduction in enzyme activity. cathepsin D from R. philippinarum exhibited high thermostability up to 50°C and activity at pH 2-4. Its stability and characteristics are comparable to those of other species, which opens avenues in biotechnology for protein hydrolysis and peptide production.

Development of therapeutic peptide producers based on Escherichia coli BL21 and their cultivation technology

Introduction. Peptides with a molecular weight of less than 5 kDa have been used in medicine and biotechnology over the past decade for the treatment of various diseases. However, chemical synthesis peptide has several disadvantages, including low yield, reduced efficiency, and high costs. An alternative approach to peptide production is the use of the Escherichia coli expression system. The development of effective peptide synthesis technology remains a critical task because of the low productivity of recombinant strains.Aim. Developing highly efficient strains of Escherichia coli BL21 expressing therapeutic peptides with a molecular weight of less than 5 kDa in E. coli and their cultivation technology.Materials and methods. Genetic constructs were obtained using the restriction-ligase method, and their authenticity was confirmed by Sanger sequencing. Cultivation technology was developed using the Design of Experiments approach. The cultivation condition was validated in the Biostat B bioreactor. Hybrid proteins were purified by metal-chelate chromatography, followed by hydrolysis ULP proteas to obtain the target peptides. The quantitative content of the target protein was determined by capillary electrophoresis, and the authenticity of the protein was confirmed by HPLC-MS and ELISA.Results and discussion. Highly efficient peptide-producing strains were developed. Cultivation conditions were optimized: рН 7.5 ± 0.5, cultivation temperature 37 °C, induction optical density 28 ± 2, IPTG concentration 0.05 мМ. The productivity of the producer strains was up to 4.82 ± 0.05 g/L. Furthermore, samples of the target peptides were isolated and purified.Conclusion. The productivity of peptides in this study were significantly higher than in previous research. The presented strategy for strain development, cultivation and purification technology can be used production of therapeutic peptides with diverse physical chemicals characteristics in the future.

P-21 POSSIBLY ECTOPIC PTH SECRETION IN A WOMAN WITH METASTATIC BREAST CANCER

Abstract Introduction Hypercalcemia is a common complication in malignancies, with various causes such as tumor secretion of parathyroid hormone-related peptide (PTHrP), osteolytic metastases or tumor-induced calcitriol production. Ectopic production of parathyroid hormone (PTH) is a rare cause of hypercalcemia. This report presents a rare case of metastatic breast cancer possibly associated with ectopic PTH secretion. Clinical Case A 66-year-old female with a history of invasive ductal carcinoma and metastases of bone and liver was referred to our endocrinology clinic due to persistent hypercalcemia. She had been presented with atypical-pathological femur fracture 2 years ago and metastatic breast cancer had been detected. Her primary cancer treatment included conventional chemotherapy and immunotherapy over the past 2 years. She had been already treated with zoledronic acid from the beginining of the chemotherapy for her bone metastases. During her follow up hypercalcemia had been detected at the 30 th month of the therapy; her calcium was around 9-10 mg/dl and increased to 12 mg/dl abruptly while shewas on zoledronic acid. Laboratory tests showed elevated PTH levels accompanying hypercalcemia. Neck ultrasound and parathyroid scintigraphy were negative for any parathyroid pathology. A biopsy of the liver metastasis was performed during the transarterial chemoembolization procedure to make an immunohistochemical staining for PTH but it was negative. The patient was given cinacalcet with changing dosages according to the calcium levels besides zoledronic acid. Under these medications both calcium and PTH levels continued to rise;during a short period which she could not take cinacalcet because of side effects, her calcium was measured 17.5mg/dl,and didn't come to normal levels despite glucocorticoid and furosemide treatment which she subsequently required hemodialysis. Zoledronic acid was replaced with denosumab. Although calcium levels were controlled with denosumab and low dosage cinacalcet PTH levels remained elevated, suggesting ongoing ectopic PTH secretion. With no identifiable parathyroid hormone source and persistent high PTH levels despite normalized calcium, the diagnosis of ectopic PTH production was assumed. Besides the high levels of PTH we couldn't visualize a lesion secreting PTH on the contrary of direct relationship between the volume of parathyroid lesions and PTH levels. Conclusion This case represents a rare complication of metastatic breast cancer possibly associated with ectopic PTH production causing hypercalcemia. Despite extensive imaging,no parathyroid adenoma or alternative explanation for the elevated PTH was found, reinforcing the need for awareness of ectopic hormone production in the management of hypercalcemia in cancer patients. Early recognition and appropriate management of such atypical cases are crucial to avoid unnecessary interventions and to tailor treatment strategies effectively.

Antioxidant Peptides from Hizikia fusiformis: A Study of the Preparation, Identification, Molecular Docking, and Cytoprotective Function of H2O2-Damaged A549 Cells by Regulating the Keap1/Nrf2 Pathway

Hijiki (Hizikia fusiformis) is a seaweed native to warm-temperate and subtropical regions that has a high edible value and economic value, with a production of about 2 × 105 tons/year. Current research has clearly shown that the pharmacological activities of active ingredients from hijiki have covered a broad spectrum of areas, including antioxidant, hypoglycemic, antiviral, anticoagulant, anti-inflammatory, intestinal flora modulation, anti-aging, antineoplastic and antibacterial, and anti-Alzheimer’s disease areas. However, no studies have reported on the production of antioxidant peptides from hijiki proteins. The objectives of this study were to optimize the preparation process and explore the cytoprotective function and mechanisms of antioxidant peptides from hijiki protein. The results indicated that papain is more suitable for hydrolyzing hijiki protein than pepsin, trypsin, alkaline protease, and neutral protease. Under the optimized parameters of an enzyme dosage of 3%, a material–liquid ratio of 1:30, and an enzyme digestion time of 5 h, hijiki hydrolysate with a high radical scavenging activity was generated. Using ultrafiltration and serial chromatographic methods, ten antioxidant oligopeptides were purified from the papain-prepared hydrolysate and identified as DGPD, TIPEE, TYRPG, YTPAP, MPW, YPSKPT, YGALT, YTLLQ, FGYGP, and FGYPA with molecular weights of 402.35, 587.61, 592.64, 547.60, 532.53, 691.77, 523.57, 636.73, 539.58, and 553.60 Da, respectively. Among them, tripeptide MPW could regulate the Keap1/Nrf2 pathway to significantly ameliorate H2O2-induced oxidative damage of A549 cells by increasing cell viability and antioxidant enzyme (SOD, CAT, and GSH-Px) activity, decreasing ROS and MDA levels, and reducing the apoptosis rate. Molecular docking experiments show that HFP5 (MPW) exerts its inhibitory effect mainly through hydrogen bonds and hydrophobic interactions with the Kelch domain of the Keap1 protein, eventually facilitating the translocation of Nrf2 to the nucleus. Therefore, antioxidant peptides from hijiki can be applied to develop algae-derived health foods for treating diseases associated with oxidative stress.

Development of Synthetic Antimicrobial Peptides Based on Genomic Analysis of Streptococcus salivarius.

In the oral environment, the production of bacteriocins or antimicrobial peptides (AMPs) plays a crucial role in maintaining ecological balance by impeding the proliferation of closely related microorganisms. This study aims to conduct in silico genome screening of Streptococcus salivarius to identify potential antimicrobial compounds existing as hypothetical peptides, with the goal of developing novel synthetic antimicrobial peptides. Draft genomes of various oral Streptococcus salivarius strains were obtained from the NCBI database and subjected to analysis using bioinformatic tools, viz. Expert Protein-Analysis System (Expasy), UniProt Knowledgebase (UniProtKB), European Molecular Biology Open Software Suite (EMBOSS), Pepwheel, and PEP-FOLD Peptide Structure Prediction Server. The antimicrobial potential of peptides was assessed through the Antimicrobial Peptide Database (AMP) and Bactibase. Two short peptides, viz. synthetic antimicrobial peptides (SAMPs), were designed based on current knowledge of hydrophobic and cationic residues, synthesized, and their efficacy against biofilm formation was evaluated with standard microbiological methods. The synthesized short peptides reduced the growth and effectively inhibited biofilm formation by specific oral microbial strains, demonstrating their potential as antimicrobial peptides. Furthermore, the alignment of bacteriocin biosynthetic clusters among streptococcus strains revealed variations in putative bacteriocin amino acid sequences across different strains of the same organism. Streptococcus salivarius emerges as a promising bioresource for the development of novel antimicrobial agents, particularly for combating biofilm-associated oral infections.

Highly Selective α-Addition and β-Conjugate Addition Products from Peptides Composed of α,β-Unsaturated γ-Amino Acids.

β-Addition products are common in conjugate addition reactions consisting of α,β-unsaturated carbonyl compounds. Here, we are reporting an uncommon α-addition product as a major product in the thioacetic acid conjugate addition reaction on a peptide consisting of (E)-α,β-unsaturated γ-amino acids. In addition, we observed highly diastereoselective β-addition products from the thiophenol and thioethanol conjugate addition reaction on peptides. In comparison, (E)-α,β-unsaturated γ-amino amides give both α- and β-addition products with thioacetic acid and only β-addition products in the thiophenol conjugate addition reaction. Further, the conformations of both α-addition and β-addition products were studied in single crystals as well as in solution. The peptide product with α-thioacetate addition (α,γ-disubstituted γ-amino acid) adopted a regular 12-helix conformation, whereas β-addition (β,γ-disubstituted γ-amino acid) products slightly distorted 12-helix conformation. A kink is observed at the site of β-addition in the 12-helix structures of all β-addition products. Overall, the uncommon and stereospecific conjugate addition reactions reported here can be explored to introduce diverse functional groups to the peptide backbone.

Natural Cyclic Peptides: Synthetic Strategies and Biomedical Applications.

Natural cyclic peptides, a diverse class of bioactive compounds, have been isolated from various natural sources and are renowned for their extensive structural variability and broad spectrum of medicinal properties. Over 40 cyclic peptides or their derivatives are currently approved as medicines, underscoring their significant therapeutic potential. These compounds are employed in diverse roles, including antibiotics, antifungals, antiparasitics, immune modulators, and anti-inflammatory agents. Their unique ability to combine high specificity with desirable pharmacokinetic properties makes them valuable tools in addressing unmet medical needs, such as combating drug-resistant pathogens and targeting challenging biological pathways. Due to the typically low concentrations of cyclic peptides in nature, effective synthetic strategies are indispensable for their acquisition, characterization, and biological evaluation. Cyclization, a critical step in their synthesis, enhances metabolic stability, bioavailability, and receptor binding affinity. Advances in synthetic methodologies-such as solid-phase peptide synthesis (SPPS), chemoenzymatic approaches, and orthogonal protection strategies-have transformed cyclic peptide production, enabling greater structural complexity and precision. This review compiles recent progress in the total synthesis and biological evaluation of natural cyclic peptides from 2017 onward, categorized by cyclization strategies: head-to-tail; head-to-side-chain; tail-to-side-chain; and side-chain-to-side-chain strategies. Each account includes retrosynthetic analyses, synthetic advancements, and biological data to illustrate their therapeutic relevance and innovative methodologies. Looking ahead, the future of cyclic peptides in drug discovery is bright. Emerging trends, including integrating computational tools for rational design, novel cyclization techniques to improve pharmacokinetic profiles, and interdisciplinary collaboration among chemists, biologists, and computational scientists, promise to expand the scope of cyclic peptide-based therapeutics. These advancements can potentially address complex diseases and advance the broader field of biological drug development.

In ovo delivery of carvacrol triggers expression of chemotactic factors, antimicrobial peptides and pro-inflammatory pathways in the yolk sac of broiler chicken embryos

BackgroundBroiler chickens are most vulnerable immediately after hatching due to their immature immune systems, making them susceptible to infectious diseases. The yolk plays an important role in early immune defence by showing relevant antioxidant and passive immunity capabilities during broiler embryonic development. The immunomodulatory effects of phytogenic compound carvacrol have been widely reported. After in ovo delivery in the amniotic fluid during embryonic development carvacrol is known to migrate to the yolk sac. However, it is unknown whether carvacrol in the yolk could enhance defence responsiveness in the yolk sac. Therefore, the aim of this study was to improve early immune function in chicken embryos, and it was hypothesized that in ovo delivery of carvacrol would result in immunomodulatory effects in the yolk sac, potentially improving post-hatch resilience.MethodsOn embryonic day (E)17.5, either a saline (control) or carvacrol solution was injected into the amniotic fluid. Yolk sac tissue samples were collected at E19.5, and transcriptomic analyses using RNA sequencing were performed, following functional enrichment analyses comparing the control (saline) and carvacrol-injected groups.ResultsThe results showed that 268 genes were upregulated and 174 downregulated in the carvacrol group compared to the control (P < 0.05; logFC < −0.5 or log FC > 0.5). Functional analyses of these differentially expressed genes, using KEGG, REACTOME, and Gene Ontology databases, showed enrichment of several immune-related pathways. This included the pathways ‘Antimicrobial peptides’ (P = 0.001) and ‘Chemoattractant activity’ (P = 0.004), amongst others. Moreover, the ‘NOD-like receptor signaling’ pathway was enriched (P = 0.002). Antimicrobial peptides are part of the innate immune defence and are amongst the molecules produced after the nucleotide oligomerization domain (NOD)-like receptor pathway activation. While these responses may be associated with an inflammatory reaction to an exogenous threat, they could also indicate that in ovo delivery of carvacrol could prepare the newly hatched chick against bacterial pathogens by potentially promoting antimicrobial peptide production through activation of NOD-like receptor signaling in the yolk sac.ConclusionIn conclusion, these findings suggest that in ovo delivery of carvacrol has the potential to enhance anti-pathogenic and pro-inflammatory responses in the yolk sac via upregulation of antimicrobial peptides, and NOD-like receptor pathways.

Circ_0004662 contributes to colorectal cancer progression by interacting with hnRNPM.

Circular (circ)RNAs participate in colorectal cancer (CRC) occurrence and progression. However, the role of hsa_circ_0004662 (circ_0004662) in CRC remains unknown. Reverse transcription‑quantitative PCR noted high expression of circ_0004662 in CRC compared with normal colorectal epithelial cells. circ_0004662 knockdown inhibited migration of CRC cells in vitro and in vivo; would healing and Transwell assays showed that circ_0004662 overexpression contributed to CRC migration. Nuclear cytoplasmic analysis and fluorescence in situ hybridization revealed localization of circ_0004662 in the nucleus and cytoplasm. CircRNADB databases predicted that circ_0004662 exhibited translational potential and liquid chromatography‑mass spectrometry (LC‑MS) of circ_0004662 pull‑down products suggested that circ_0004662 bound to multiple ribosomal subunits. However, peptide products of 149aa translated by circ_0004662, with a molecular weight of ~17 kDa were not detected. Nevertheless, LC‑MS analysis indicated that circ_0004662 bound multiple proteins. Immunoprecipitation of RNA‑binding proteins revealed that circ_0004662 bound to heterogeneous nuclear ribonucleoprotein M (hnRNPM) and that hnRNPM interference decreased circ_0004662 expression, thereby affecting CRC progression. In summary, circ_0004662 was significantly upregulated in CRC. As a non‑coding RNA, it may promote CRC progression by binding to hnRNPM, which may serve as a potential target for treating CRC.

Attenuating ABHD17 isoforms augments the S-acylation and function of NOD2 and a subset of Crohn's disease-associated NOD2 variants.

NOD2 is an intracellular innate immune receptor that detects bacterial peptidoglycan fragments. Although nominally soluble, some NOD2 is associated with the plasma membrane and endosomal compartments for microbial surveillance. This membrane targeting is achieved through post-translational S-acylation of NOD2 by the protein acyltransferase ZDHHC5. Membrane attachment is necessary to initiate a signaling cascade in response to cytosolic peptidoglycan fragments. Ultimately, this signaling results in the production of antimicrobial peptides and pro-inflammatory cytokines. In most cases, S-acylation is a reversible post-translational modification with removal of the fatty acyl chain catalyzed by one of several acyl protein thioesterases. Deacylation of NOD2 by such an enzyme will displace it from the plasma membrane and endosomes, thus preventing signaling. To identify the enzymes responsible for NOD2 deacylation, we used engineered cell lines with RNA interference and small-molecule inhibitors. These approaches were combined with confocal microscopy, acyl-resin-assisted capture, immunoblotting, and cytokine multiplex assays. We identified α/β-hydrolase domain-containing protein 17 isoforms (ABHD17A, ABHD17B, and ABHD17C) as the acyl protein thioesterases responsible for NOD2 deacylation. Inhibiting ABHD17 increased the plasma membrane localization of wild-type NOD2 and a subset of poorly acylated Crohn's disease-associated variants. This enhanced NOD2 activity, increasing NF-κB activation and pro-inflammatory cytokine production in epithelial cells. These findings demonstrate that ABHD17 isoforms are negative regulators of NOD2. The results also suggest that targeting ABHD17 isoforms could restore functionality to specific Crohn's disease-associated NOD2 variants, offering a potential therapeutic strategy.

Guggulsterone ameliorates psoriasis by inhibiting keratinocyte proliferation and inflammation through induction of miR-17 directly targeting JAK1 and STAT3.

The pathogenesis of psoriasis involves hyperproliferation of epidermal keratinocytes and abnormal interactions between activated keratinocytes and infiltrating immune cells. Emerging evidence has shown that keratinocytes play essential roles in both the initiation and maintenance of psoriasis, suggesting that exposing keratinocytes to agents with antiproliferative and anti-inflammatory effects may be effective for psoriasis treatment. Guggulsterone (GS), a plant sterol derived from the gum resin of Commiphora wightii, possesses a variety of pharmacological activities. However, the effects of GS on psoriasis and the underlying mechanism have not been elucidated. In this study, we evaluated the therapeutic effect of GS on psoriasis using an imiquimod-induced psoriasis mouse model and investigated the effect of GS on human keratinocytes and the underlying mechanism. We found that GS effectively alleviated psoriasis-like skin lesions in imiquimod-induced psoriasis model mice and that GS suppressed the proliferation, migration, and production of proinflammatory cytokines, chemokines and antimicrobial peptides in keratinocytes. Transcriptome analysis by RNA-seq revealed that the differentially expressed genes (DEGs) induced by GS in keratinocytes were intricately linked to the pathogenesis of psoriasis. Furthermore, STAT3, a key player in the development and pathogenesis of psoriasis, was identified as a critical downstream mediator of GS in keratinocytes. Mechanistically, GS upregulated the expression of miR-17-5p, which directly binds to the 3'-untranslated regions (3'UTRs) of JAK1 and STAT3, leading to the downregulation of JAK1 and STAT3 expression. Collectively, these findings suggest that GS may serve as an effective natural compound for the treatment of psoriasis.

Bioactive Milk Peptides as a Nutraceutical Opportunity and Challenges.

The biotechnology field has witnessed rapid advancements, leading to the development of numerous proteins and peptides (PPs) for disease management. The production and isolation of bioactive milk peptides (BAPs) involve enzymatic hydrolysis and fermentation, followed by purification through various techniques such as ultrafiltration and chromatography. The nutraceutical potential of bioactive milk peptides has gained significant attention in nutritional research, as these peptides may regulate blood sugar levels, mitigate oxidative stress, improve cardiovascular health, gut health, bone health, and immune responses, and exhibit anticancer properties. However, to enhance BAP bioavailability, the encapsulation method can be used to offer protection against protease degradation and controlled release. This article provides insights into the composition, types, production, isolation, bioavailability, and health benefits of BAPs.

Genome mining and heterologous expression reveal streptacidin, a new lasso peptide from Streptacidiphilus jiangxiensis.

A lasso peptide biosynthetic gene cluster (BGC) was identified through genome mining in the species Streptacidiphilus jiangxiensis CGMCC 4.1857, which was isolated from acidic rhizosphere soil. The BGC was reconstructed in Escherichia coli, leading to the heterologous production of a lasso peptide named streptacidin. The solution structure of streptacidin was determined based on the distance constraints derived from the NOESY spectrum, establishing the first lasso peptide utilizing methionine as a steric lock for the unique spatial configuration and the remarkable stability against heat (up to 95 °C) and proteolytic degradation by carboxypeptidase Y and chymotrypsin. Under experimental conditions, streptacidin showed weak effectiveness against vancomycin sensitive Enterococcus faecalis ATCC 29212 and Pseudomonas aeruginosa ATCC 902. These findings further the understanding of this distinctive class of compounds.

Production of ACE Inhibitory Peptides via Ultrasonic-Assisted Enzymatic Hydrolysis of Microalgal Chlorella Protein: Process Improvement, Fractionation, Identification, and In Silico Structure-Activity Relationship

Production of ACE Inhibitory Peptides via Ultrasonic-Assisted Enzymatic Hydrolysis of Microalgal Chlorella Protein: Process Improvement, Fractionation, Identification, and In Silico Structure-Activity Relationship