Peptide Profiles Research Articles

Long-term dysregulation of plasma peptidome in mild and multiple COVID-19 recovered patients revealed by a novel efficient peptidomics workflow.

After recovering from COVID-19, many patients experience "long COVID" symptoms. Existing research has predominantly focused on moderate to severe cases, with limited studies examining mild cases and recurrent infections. The circulating low-molecular-weight (LMW) peptidome, involving lipid metabolism, coagulation, and immune pathways, is crucial for understanding COVID-19's long-term effects. We developed a peptidomics workflow utilizing solid-phase extraction with highly wrinkled GO-Fe3O4 composite materials (HWGO-F) and nanoLC-MS/MS detection. By altering the pH, HWGO-F enhances plasma peptide adsorption and purification. Compared to traditional methods, our workflow offers improved detection depth and reproducibility for over 70% of peptide signals with CV < 20%. We investigated plasma peptide profiles in mild COVID-19 patients post-recovery from single or second infections. The findings indicate persistent abnormalities in initial COVID-19 infections' plasma peptide profiles, gradually diminishing over time. Secondary infections prolong recovery. Disrupted functions include lipid metabolism, coagulation and complement cascades, and infection-related pathways. Lipid metabolism may normalize within 3 months, while coagulation and immune abnormalities can last 3-6 months. After secondary infections, lipid metabolism irregularities may last at least 1 month, with extended coagulation and immune imbalances. These results provide a theoretical foundation for understanding the widespread occurrence of long COVID and guide recovery care for mild cases.

Combined action of two synthetic ultrashort antimicrobial peptides exhibiting synergistic effects against clinically significant resistant bacteria

Background and Aim: The emergence and proliferation of multidrug-resistant bacteria pose a global health crisis. This issue arises from the overuse and misuse of antibiotics, coupled with the pharmaceutical industry’s limited development of new drugs, which is constrained by financial disincentives and regulatory hurdles. This study aimed to investigate the combined antibacterial efficacy and safety profile of the combined ultrashort antimicrobial peptides (AMPs) WW-185 and WOW against antibiotic-resistant bacterial strains. Materials and Methods: The WW-185 and WOW peptides were synthesized through solid-phase methods and purified using reverse-phase high-performance liquid chromatography, and their purity was confirmed by mass spectrometry. Antibacterial activity was evaluated using broth dilution and checkerboard assays to assess both individual and combined effects of the peptides against Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus [MRSA]) and Escherichia coli (including extended-spectrum beta-lactamases [ESBL]-producing strains). The synergy between the peptides was quantified using fractional inhibitory concentration indices. Hemolytic activity was also assessed to determine cytotoxicity toward red blood cells. Results: The combination of WW-185 and WOW exerted synergistic effects against both MRSA and ESBL-producing E. coli, with reduced minimal inhibitory concentrations compared with the individual treatments. The peptides exhibited minimal hemolytic activity, indicating low toxicity. Conclusion: The combination of the ultrashort AMPs WW-185 and WOW shows promising synergistic antibacterial effects against resistant bacteria, with potential for further therapeutic development due to their enhanced efficacy and low toxicity. Keywords: antimicrobial agents, bacterial infections, multidrug resistance, synergistic effects, ultra-short peptides.

Salivary peptidomic profiling of chronic gingivostomatitis in cats by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry and nanoscale liquid chromatography-tandem mass spectrometry.

Chronic gingivostomatitis in cats (FCGS) is a moderately to severely painful condition, potentially caused by inadequate immune response to oral antigenic stimulation. Salivary peptidome analysis can identify inflammatory protein mediators and pathways involved in oral mucosal immune activation and may indicate potential therapeutic options for FCGS. Evaluate the diversity and abundance of salivary peptides in cats with FCGS using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and nanoscale liquid chromatography-tandem mass spectrometry (nano LC-MS/MS). Thirty-two cats with FCGS and 18 healthy controls. Case-control cross-sectional study. We compared the salivary peptide profiles of diseased and healthy cats. The diagnosis of FCGS was confirmed by histopathology. Saliva samples were analyzed for viral infections using polymerase chain reaction (PCR), peptide mass fingerprint (PMF) using MALDI-TOF MS, and peptide identification using nano LC-MS/MS. Distinct clusters of peptide profiles were observed between groups. In FCGS, 26 salivary peptides were altered, including apolipoprotein A1, nuclear receptor subfamily 1 group I member 3, fibrinogen alpha chain, interleukin 2 receptor gamma, interleukin 23 receptor, hemoglobin subunit alpha, and serpin peptidase inhibitor clade A (alpha-1 antiproteinase, antitrypsin) member 12, protein-tyrosine-phosphatase, and cholinergic receptor nicotinic alpha 10 subunit. Protein-anti-inflammatory drug interaction networks were observed. Peptide mass fingerprint and peptide profiles identified distinct clusters between FCGS and healthy cats. The 9 novel salivary peptide markers were associated with the JAK/STAT and PI3K/Akt pathways and immune responses. These potentially noninvasive biomarkers may facilitate understanding of FCGS pathophysiology and guide future therapeutic research.

Successful combination of lactic acid bacteria and yeast fermentation and enzymatic treatment to re-cycle industrial bread by-products for bread making

Bread industry generates significant amounts of by-products which are discarded every day with relevant economic and environmental repercussions, despite they still contain high concentrations of potentially exploitable nutrients. Aiming to develop new sustainable solutions, this study explored the synergistic application of enzymatic treatment and sourdough fermentation to re-cycle industrial bread by-products for new sourdough bread making. Lactiplantibacillus plantarum SD69. B2 and Saccharomyces cerevisiae SD69. E3 were used as starters, while α-amylase, amyloglucosidase and protease were assessed for their ability to hydrolyze starch and proteins, providing more available carbon and nitrogen sources for the microorganisms. The bread waste-based sourdoughs made by combining protease and L. plantarum SD69. B2 alone or in combination with S. cerevisiae SD69. E3 were selected based on acidification and growth kinetics, and their biochemical, amino acid, and peptide profiles were also characterized demonstrating promising properties. Therefore, they were used, at different percentages, for bread making. Although a slightly acidic pH and a low leavening power, due to the denatured proteins and gelatinized starch in the bread by-products, the texture and sensory analyses of new breads revealed better textural attributes, smell, acidic taste, and overall acceptability compared to the control. The possible reasons behind such features were discussed. The overall results demonstrated that the approach proposed in this study was effective to valorize bread by-products, and it represents a starting point to develop strategies responding to the current perspective of circular economy in food industry.

Lipid-mediated adaptation of proteins and peptides in cell membranes

The paper overviews the results of computational studies of the molecular mechanisms underlying the adaptation of model cell membranes taking place during their interaction with proteins and peptides. We discuss changes in the structural and dynamic parameters of the water–lipid environment, the hydrophobic/hydrophilic organization of the lipid bilayer surface (the so-called “mosaicity”), etc. Taken together, these effects are called the “membrane response” (MR) and constitute the most important ability of the cell membranes to respond specifically and consistently to the incorporation of extraneous agents, primarily proteins and peptides, and their subsequent functioning. The results of the authors’ long-term research in the field of molecular modeling of MR processes with various spatial and temporal characteristics are described, from the effects of binding of individual lipid molecules to proteins to changes in the integral macroscopic parameters of membranes. The bulk of the results were obtained using the “dynamic molecular portrait” approach developed by the authors. The biological role of the observed phenomena and potential ways of rationally designing artificial membrane systems with specified MR characteristics are discussed. This, in turn, is important for targeted changes in the activity profile of proteins and peptides exerting action on biomembranes, not least as promising pharmacological agents.

Enhanced Oligopeptide and Free Tryptophan Release from Chickpea and Lentil Proteins: A Comparative Study of Enzymatic Modification with Bromelain, Ficin, and Papain.

Plant-based foods offer a sustainable alternative to meet the growing protein demand. Legumes are the most promising of these, as they contain relatively high concentrations of protein, low digestible starch, and dietary fiber, as well as them possibly featuring low levels of fat. Enzymatically modified legume proteins provide us with tempting perspectives in terms of enhancing foods' biological values. However, their bioavailability and digestibility are generally less sufficient than that of proteins of animal origin, which may be improved by well-tailored enzyme modification. In this study, the efficacy of three plant-based proteases (bromelain, ficin, and papain) were evaluated at two distinct concentrations (2.5% and 10%) and three hydrolysis durations (1, 2, and 12 h) when transforming chickpea and lentil proteins. The degree of hydrolysis (DH), peptide profiles, and free amino acid content were analyzed to determine the efficiency of each enzyme. Results showed significant variations in DH, which was influenced by enzyme type, concentration, and hydrolysis duration. Papain exhibited the highest DH, particularly at a 10% concentration, reaching 27.8% efficiency in chickpea and 34.8% in lentils after 12 h. Bromelain and ficin were proven to be less effective, with ficin showing the least hydrolytic activity. SDS-PAGE analysis revealed substantial protein degradation, especially subsequent to papain treatment, pointing out that most proteins were cleaved into smaller peptides. SEC-HPLC indicated a predominant release of peptides within the 200-1000 Da range, suggesting enhanced bioavailability. Papain and bromelain treatments resulted in a significant release of oligopeptides and dipeptides. UHPLC analysis highlighted a marked post-hydrolysis increase in total free amino acids, with arginine, leucine, and lysine being the most abundant ones. Notably, tryptophan, being undetectable in untreated samples, was released in measurable amounts post-hydrolysis. These findings demonstrate papain's superior performance in protein hydrolysis and its potential in producing bioactive peptides, highlighting its applicability in food processing and the development of both nutraceuticals and functional foods.

Assessing the impact of bacterial blends, crosslinking enzyme and storage times on volatile and non-volatile compound production in fermented pea protein emulsion gels

Pea protein is a promising ingredient for plant-based cheese production but has poor consumer acceptance due to intrinsic beany flavors. Fermentation could potentially decrease these off-flavors while also producing desirable cheese-like aromas. Pea protein emulsion gels were fermented using four different bacterial blends for 16 weeks with and without the crosslinking enzyme transglutaminase. The volatile organic compound (VOC) profiles were assessed by GC–MS and the peptide profile was measured by LC-MS/MS during storage. VOC production was mainly affected by the composition of the bacterial blends, followed by storage time. Crosslinking of the protein gel structure had minimal impact on VOC production. The peptide-level profiling revealed that crosslinking can reduce peptide size and the production of bitterness-like peptides in some blends. This study provides insights into the effect of bacterial blends, storage time, and enzymatic crosslinking on the production of volatile components and peptides related to aroma and peptide profiles for pea protein.

Development of 3D-Printed Two-Compartment Capsular Devices for Pulsatile Release of Peptide and Permeation Enhancer.

The oral absorption of a peptide is driven by a high local concentration of a permeation enhancer (PE) in the gastrointestinal tract. We hypothesized that a controlled release of both PE and peptide from a solid formulation, capable of maintaining an effective co-localized concentration of PE and peptide could enhance oral peptide absorption. In this study, we aimed to develop a 3D-printed two-compartment capsular device with controlled pulsatile release of peptide and sodium caprate (C10). 3D-printed two-compartment capsular device was fabricated using a fused deposition modeling method. This device was then filled with LY peptide and C10. The release profile was modulated by changing the thickness and polymer type of the capsular device. USP apparatus II dissolution test was used to evaluate the impacts of device thickness and polymer selection on release profile in vitro. An optimal device was then enteric coated with HPMCAS. A strong linear relationship between the thickness of capsular devices and the delay in the release onset time was observed. An increase in the device thickness or the use of PLA decreased the release rate. The capsular device with compartment 1, compartment 2 and fence thickness of 0.4; 0.95 and 0.5mm, respectively, and the use of PVA achieved desired pulsatile release profiles of both peptide and C10. Furthermore, enteric-coated capsular devices with HPMCAS had similar pulsatile release profiles compared to non-enteric coated devices. These findings suggest potential application of 3D-printing techniques in the formulation development for complex modified drug release products.

Unveiling the slow digestion and peptide profiles of polymerised whey gel via heat and TGase crosslinking: An in vitro/vivo perspective

Polymerised whey is widely used in dairy products and can affect digestibility when its high-molecular-weight aggregates and gel structure are modified. This study investigated the digestibility, peptide profiles and satiety of modified whey protein isolate (MWPI) pre-heated with transglutaminase. Results showed that 43.06 % of MWPI was digested during the 4-h in vitro digestion, indicating a slow digestion rate. Compared with whey protein isolate (WPI), MWPI yielded 103 peptides with higher abundance following in vitro digestion, including 17 angiotensin-converting enzyme inhibitors and 1 dipeptidyl peptidase-4 inhibitor. Visual analytics indicated differential peptides located at distinct α-helix and β-sheet of β-lactoglobulin, α-lactalbumin and bovine serum albumin. MWPI gavage extended stomach retention time, decreased intestinal propulsion rate from 75.60 % (WPI group) to 33.72 % in 30 min and enhanced satiety within 120 min compared with WPI. Overall, whey polymerisation modulates protein–enzyme interactions, releasing different peptides and enhancing satiety.

The Variability of the Salivary Antimicrobial Peptide Profile: Impact of Lifestyle.

Saliva is crucial in maintaining oral health; its composition reflects the body's physiological and diseased state. Among salivary components, antimicrobial peptides (AMPs) stand out for their broad antimicrobial activities and role in modulating the oral microbiota and innate immune response. Local and systemic diseases can affect the levels of AMPs in saliva, making them attractive biomarkers. However, the large variability in their concentrations hampers their use in diagnostics. Knowledge of the various factors influencing the profile of salivary AMPs is essential for their use as biomarkers. Here, we examine how lifestyle factors such as physical activity, dietary supplementation, tobacco smoking, and psychological stress impact salivary AMP levels. By understanding these sources of variability, we can take a step forward in using AMPs for diagnostics and prognostics and develop new tailored and preventative approaches.

Hydrolysates of mare's milk proteins. Immunochemical and physico-chemical characteristics

In recent years, the attention of specialists has been attracted by a significant increase in allergic diseases, especially among children. Enzymatic hydrolysis with the participation of peptidases is considered the most effective measure to reduce the allergenicity of milk proteins. The study of the features of protein proteolysis by various enzymes, aimed at establishing optimal process parameters, is the subject of research in the production of hydrolysates with specified properties: a certain peptide and amino acid profile, reduced antigenic properties. At the same time, for a correct preclinical assessment of the safety and potential effectiveness of specialized food products, it is not enough only to determine the molecular weight distribution of peptide fractions in the composition. A necessary additional and informative indicator of reducing the potential allergenicity of the hydrolysate is the degree of preservation of the antigenic properties of the initial protein (residual antigenicity), determined by immunochemical methods. The preparation and subsequent comprehensive assessment of enzymatic hydrolysates of mare's milk proteins is of considerable interest, since, according to the results of clinical studies, it was suggested that upon allergy to cow's milk proteins mare's milk can be considered hypoallergenic. The purpose of this work was to obtain enzymatic hydrolysates of mare's milk proteins using domestic enzymes and their further physico-chemical and immunochemical characteristics. The object of the study was mare's milk protein obtained from skimmed mare's milk powder as a protein substrate. Two samples of enzymes from various manufacturers of the Russian Federation were used in the work. The results of the conducted studies show that the peptide profiles of hydrolysates vary greatly depending on the enzyme used, however, the multiplicity of antigenicity reduction practically does not depend on the nature of the enzyme, and does not depend on an increase in the enzyme/substrate ratio. The peptide profile and the multiplicity of reducing the antigenicity of hydrolysates of mare's milk proteins are influenced by ultrafiltration treatment of the obtained hydrolysates, which allows reducing the content of antigenic structures in the final product by several orders of magnitude.

Influence of lecithin on the digestibility and immunoreactivity of β-conglycinin

A growing body of evidence suggests that protein structure can be uniquely altered by lipids. However, the role of lecithin on the digestibility and immunoreactivity of allergenic protein remains poorly understood. Therefore, we investigated the impact of different protein/lecithin (P:L) ratios (5:1, 10:1, 20:1, 30:1 and 40:1) on the digestion properties, peptide profiles and immunoreactivity of β-conglycinin in vitro simulated gastrointestinal digestion. Results revealed that lecithin addition increased the degree of hydrolysis and digestion rate of β-conglycinin during digestion in a dose-dependent manner, which may be attributed to the enhancement of pepsin activity. Additionally, the addition of lecithin contributed to the dispersion and homogeneity of β-conglycinin digestion products. When the ratio of lecithin to β-conglycinin was 1:10, the obtained β-conglycinin digestion products exhibited the highest DH value (23.80 %) and the lowest antigenicity (52.69%) in the intestinal digestion. Peptidomics and immunoinformatic analysis further confirmed that PL-10 disrupted 18/30, 15/44, and 37/75 epitopes in the α, α′, and β subunits of β-conglycinin, respectively. These results suggested that lecithin changed the cleavage preferences of β-conglycinin, and promoted the disruption of allergic epitopes, specifically for the β subunit. The study can contribute to our understanding of the role of lecithin in the digestion properties and immunoreactivity of allergenic protein.

Effect of ultrasound and enzymatic pre-treatments on the profile of bioactive peptides of beef liver hydrolysates

The use of meat by-products as a potential source of protein hydrolysates rich in bioactive peptides is of growing interest to valorise these products and improve their sustainable use. This study aimed to evaluate the effect of different pre-treatments (hydrolysis with pepsin, ultrasounds, and ultrasounds-assisted pepsin hydrolysis) on the peptide profile and bioactivity of beef liver hydrolysed with flavourzyme. The pre-treatments with pepsin increased the degree of hydrolysis and generation of free amino acids in the liver hydrolysates, whereas the subsequent hydrolysis with flavourzyme influenced the molecular weight distribution of the peptides. Samples pre-treated with pepsin and ultrasounds-assisted pepsin hydrolysates showed the highest values of antioxidant and inhibitory activity of ACE-I, ECE-I, DPP-IV, and neprilysin enzymes, and therefore these hydrolysates were characterised to obtain the bioactive peptide profiles. A total of 995 peptides were identified by tandem mass spectrometry in the most active fractions separated by reversed-phase liquid chromatography, and 20 of them were predicted as potentially responsible for the observed bioactivities and subsequently characterised by in silico tools. These results evidenced the potential of hydrolysis pre-treatments with pepsin and ultrasounds-assisted pepsin to obtain beef liver hydrolysates rich in bioactive peptides that could exert multifunctional bioactivities such as antioxidant, antihypertensive, and antidiabetic, while giving added value to this meat by-product.

Identification of an osteopontin structural element for the restoration of a normal endometrial epidermal growth factor (EGF) profile determined by the EGF concentration on day 3 of estrous cycle and pregnancy outcome in repeat breeder dairy cows

The loss of a cyclic change with two peaks of increased endometrial epidermal growth factor (EGF) concentration on days 2–4 and 13−14 during the estrous cycle has been linked to low fertility in repeat breeder (RB) cows. We have shown that an intravaginal infusion of osteopontin (OPN) restored the EGF profile in RB cows. The present study aimed to determine a structural element of OPN to restore the normal EGF profile and fertility. Holstein RB cows were diagnosed the EGF profile by a single examination of the endometrial EGF concentration on day 3 of the estrous cycle. Those with an altered EGF profile were intravaginally infused with OPN and its fragments on the day of insemination (day 0); the concentration of endometrial EGF was measured on day 3, and pregnancy was diagnosed on days 30–35. In Study 1, recombinant OPN (rOPN) (16 nmol), thrombin-cleaved N- and C-terminal fragments of rOPN (N-rOPN and C-rOPN, respectively), and a combination of these fragments (Th-rOPN) were infused (n = 13–20). The restoration rate of the normal EGF profile of the N-rOPN group (25.0 %) was a level in between the C-rOPN group (7.7 %) and both the rOPN (55.6 %) and Th-rOPN (64.3 %) groups. In Study 2, PBS (n = 47), rOPN (9.5 nmol, n = 83), and peptides of integrin binding motifs, GRGDSVAYGLK (peptide 1; 32, 320, and 1600 nmol), GRGDS (peptide 2; 320 and 1600 nmol), and SVAYGLK (peptide 3; 320 and 1600 nmol), were infused (n = 20–25). Restoration rates of the normal EGF profile of peptide 1 (320 and 1600 nmol) and peptide 3 (1600 nmol) groups (44.0−56.3 %) were comparable with those of the rOPN group (63.9 %) and higher than those of the PBS group (15.6 %). Restoration rates of the other groups were similar to those of the PBS group. Additional cows received infusions to determine the effect on fertility. Conception rates of the peptide 1 (320 and 1600 nmol; n = 50 each), peptide 3 (1600 nmol; n = 55), and rOPN (n = 111) groups (41.8−50.0 %) were comparable and higher than that of the PBS group (21.6 %, n = 75). In Study 3, PBS (n = 24), peptide 1 (320 nmol; n = 78), and GRGESVAYGLK peptide (peptide 4; 320 and 1600 nmol; n = 50 and 26, respectively) were infused. Restoration rates of the normal EGF profile of peptide 4 and PBS groups (16.0−19.2 %) were comparable and lower than those of the peptide 1 group (44.9 %). Thus, the SVAYGLK motif may be an OPN structural element to restore the normal EGF profile and fertility in RB cows, and the RGD motif may enhance its effect.

Effect of Bezafibrate and Ginkgo biloba Extract Combination on Doxorubicin-Induced Cardiotoxicity in Rats

Objectives: This study aimed to evaluate the possible synergistic effect of bezafibrate and ginkgo biloba (GKB) extract on cardiotoxicity induced by doxorubicin. Methods: Thirty rats were allocated into 5 groups: The negative control group was treated daily with 1 ml of distilled water orally by gavage tube; the positive control received doxorubicin 3.7 mg/kg on day 11 for 3 days intraperitoneally; the bezafibrate group received 100mg/kg orally by gavage tube; the GKB group received 60mg/kg orally by gavage tube; and the combination of bezafibrate and GKB group. All the groups received the doxorubicin protocol, with an exception for the negative control. The treatment continued for 14 days. On day 14, blood samples were taken for the measurement of serum levels of troponin, natriuretic peptide, creatine phosphokinase (CPK), IL-6, and total lipid profile. The atherogenic index, cardiac risk, and LDL/HDL ratios were calculated. Cardiac tissues were sent for histopathological analysis. Results: Both bezafibrate and GKB exhibited attenuation of troponin, natriuretic peptides, CPK, IL-6, TG, cardiac risk ratio, and atherogenic index, as well as an increase in HDL levels. However, the combination group showed the greatest effect compared to the positive control group. The histopathological findings supported the biochemical outcomes. Conclusions: Combining GKB extract and bezafibrate protects against cardiac injury by restoring injury markers and IL-6, as well as improving the lipid profile, cardiac risk ratio, and atherogenic index.

Influence of enzymatic hydrolysis conditions on antimicrobial activities and peptide profiles of milk protein-derived hydrolysates from white wastewater

The focus of our investigation lies in the hydrolysis of milk proteins found in the substantial wastewater generated by the dairy industry, particularly in the white and cleaning wastewater resulting from rinsing and cleaning-in-place processes in order to enhance the value of dairy constituents by producing a diverse population of peptides, including potential antimicrobial peptides generated by 4 different enzymes: pepsin, trypsin, pronase E, and thermolysin. The protein/peptide content was influenced by the degree of hydrolysis values ranging from 2 % to 13 %, and UPLC-MS/MS characterization reveals distinct peptide sequences in enzymatic hydrolysates. The impact of hydrolysis time was also examined, revealing significant differences between 30 minutes and 240 minutes, with 555 peptides identified at 30 minutes, increasing to 693 at 240 minutes. After 4 hours, grouping showed variations: 181 peptides (thermolysin), 153 (pepsin), 126 (trypsin), and 83 (pronase E). A comparative analysis of the characterized sequences with antimicrobial peptides databases identified 17 antimicrobial peptides after 240 minutes pronase E and thermolysin hydrolysis, though they were insufficient to inhibit strains like Clostridium tyrobutyricum and Pseudomonas aeruginosa. Antimicrobial assays also revealed that peptides from Pronase T30, Pronase T240, and Thermolysine T240 exhibited antifungal activity against Mucor racemosus (MIC 2.5 mg/mL), but none against Penicillium commune. The effet of enzymatic hydrolysis demonstrated in this study highlights, for the first time, the potential for valorizing dairy white wastewater within the context of a circular economy framework.

Effect of enzymatic hydrolysis and ultrasound pretreatment on allergenicity, functional properties and bioactivity of whey protein isolates

Whey protein isolate (WPI) is an important food ingredient and a major allergen in food. Enzymatic hydrolysis is an important method for WPI modification, but there is limited information on the effect of ultrasound pretreatment on WPI hydrolysates (WPH). The aim of this study was to analyze the effect of enzymatic hydrolysis and ultrasound pretreatment on the allergenicity, functional properties and bioactivity of WPH by multispectroscopy and peptidomics combined with bioinformatics. The results showed that ultrasound pretreatment contributed to the production of WPH with low allergenicity (IgE binding capacity is 55.59%) and good functional properties (emulsifying activity index is 27.02%, foaming characteristic is 50.00%) and bioactivity (total antioxidant capacity is 65.94%). This was attributed to the synergistic hydrolysis of WPI by endopeptidases and exopeptidases, and ultrasound pretreatment that altered the accessibility of WPI to proteases and the peptide profiles and main proteins of WPH, affecting the changes in their spatial and primary structure. This research will advance the application of WPI in hypoallergenic foods.

Safety Profile of SGLT2 Inhibitor and Glucagon-Like Peptide 1 Receptor Agonist (GLP-1 RA) Use in Patients with CKD

Safety Profile of SGLT2 Inhibitor and Glucagon-Like Peptide 1 Receptor Agonist (GLP-1 RA) Use in Patients with CKD

Effect of In Vitro Digestion on Bioactive Peptides Related to Immune and Gut Health in Intact Cow's Milk and Hydrolyzed Protein-Based Infant Formulas.

Background/Objectives: Human milk is the optimal source of nutrition and protection against infection for infants. If breastfeeding is not possible, standard and hydrolyzed infant formulas (IF) are an alternative. Extensively hydrolyzed IFs (eHFs) contain bioactive peptides, but their activities have rarely been evaluated. The aim of this study was to characterize and compare the bioactive peptide profiles of different eHFs and standard IFs before and after in vitro digestion. Methods: Two forms, liquid and powder, of intact protein formula (iPF) and eHF were subjected to in vitro gastrointestinal digestion, mimicking a young infant's gut (age 0-4 months) and an older infant's gut (>6 months). Bioactive peptides of in vitro digested and undigested formulas were analysed with Liquid Chromatography-Mass Spectrometry (LC-MS). Results: In all samples, a variety of peptides with potential bioactive properties were found. Immuno-regulatory peptides, followed by antimicrobial and antioxidative peptides were most frequent, as were peptides promoting wound healing, increasing mucin secretion, regulating cholesterol metabolism, and preventing bacterial infection. Peptides typically found in yoghurt and colostrum were identified in some formula samples. Conclusions: The high amounts of bioactive peptides with various properties in eHFs and iPFs indicate a possible contribution to infection protection, healthy gut microbiomes, and immunological development of infants. eHFs showed similar compositions of bioactive peptides to iPFs, with intermittently increased peptide variety and quantity.

Comprehensive structural investigation of a potent and selective CXCR4 antagonist via crosslink modification

Macrocyclization presents a valuable strategy for enhancing the pharmacokinetic and pharmacodynamic profiles of short bioactive peptides. The exploration of various macrocyclic characteristics, such as crosslinking tethers, ring size, and orientation, is generally conducted during the early stages of development. Herein, starting from a potent and selective C-X-C chemokine receptor 4 (CXCR4) cyclic heptapeptide antagonist mimicking the N-terminal region of CXCL12, we demonstrated that the disulfide bridge could be successfully replaced with a side-chain to side-chain lactam bond, which is commonly not enlisted among the conventional disulfide mimetics. An extensive investigation was carried out to explore the chemical space of the resulting peptides, including macrocyclization width, stereochemical configuration, and lactam orientation, all of which were correlated with biochemical activity. We identified a novel heptapeptide that fully replicates the pharmacological profile of the parent peptide on CXCR4, including its potency, selectivity, and antagonistic activity, while demonstrating enhanced stability in a reductive environment. At this stage, computational studies were instructed to shed light on how the lactam cyclization features influenced the overall structure of 21 and, in turn, its ability to interact with the receptor. We envisage that these findings can give new momentum to the use of lactam cyclization as a disulfide bond mimetic and contribute to the enhancement of the repertoire for peptide-based drug development, thereby paving the way for novel avenues in therapeutic innovation.