Bioactive Peptides Research Articles

Angiotensin-I converting enzyme (ACE) inhibitory bioaccessible peptides obtained from protein extracts of Macrocystis pyrifera and Chondracanthus chamissoi seaweeds

Hypertension is a paramount chronic health concern, underscoring the critical need for preventive measures in public health. In recent years, research has discovered natural anti-hypertensive agents, including those derived from macroalgae. This study focuses on enzymatically hydrolyzing protein extracts from Macrocystis pyrifera and Chondracanthus chamissoi seaweeds to yield angiotensin I-converting enzyme (ACE) inhibitory peptides, potentially applicable in both food and bioactive products. ACE inhibitory activity was evaluated for enzymatic hydrolysates generated using bromelain, papain, and alcalase. Notably, hydrolysates produced using alcalase demonstrated the highest effect, yielding 74 % ACE inhibition for M. pyrifera and 58 % for C. chamissoi protein extracts. Optimization efforts focused on hydrolysis conditions, varying hydrolysis time and substrate-to-enzyme ratio, resulting in peak ACE inhibition of 79.9 % for M. pyrifera (5.3 h, 12.7 S:E ratio) and 70.3 % for C. chamissoi (6 h, 10 S:E ratio).Further analysis explored the relationship between molecular size separation and ACE inhibitory activity in algae hydrolysates. Fractionation via ultrafiltration revealed that fractions below 3 kDa exhibited the highest ACE inhibitory potency. Additionally, in vitro digestion studies employing pepsin and pancreatin treatments demonstrated the bioaccessibility of the seaweed-derived bioactive peptides, with maintained or enhanced bioactivity post-digestion. These findings underscore the potential of protease hydrolysates from M. pyrifera and C. chamissoi as sources of ACE inhibitory activity. Consequently, they present an exciting natural source of functional ingredients or nutraceuticals for hypertension management, with the benefits of easy implementation, profitability, and sustainability in their production process.

Anticancer Activities of Bromelain Hydrolysate of Soy Protein Against Breast Cancer Cells MCF-7

Soybeans contain proteins that have the potential to produce anticancer bioactive peptides. This study aims to determine the anticancer activity of soy protein hydrolysate against MCF-7 breast cancer cells. Soybean protein hydrolyzed by bromelain enzyme 0.5% (w/v) at the optimum temperature and pH for protein hydrolysis using the Bergmeyer and Grassl method. The degree of hydrolysis value of protein hydrolysate was determined by the Alder-Niesen method and the protein profile was analyzed by SDS-PAGE. The hydrolysate with the best degree of hydrolysis value was analyzed for anticancer activity against MCF-7 breast cancer cells by the Presto Blue assay method, and fractionation of protein hydrolysates by gel filtration chromatography (Sephadex G-15). The molecular weight of the peptide was characterized by LCMS/MS. Soy protein hydrolysis using 0.5% (w/v) bromelain enzyme was optimum at 65 ºC and pH 7.0 for 4 hours, with a hydrolysis degree value of 20.57%. The SDS-PAGE analysis showed that the protein hydrolysates had quite thick protein bands in the range of <35 kDa with an IC50 value of 70.37 mg/mL. Based on the LCMS/MS results, the peptide from fractionation has a molecular weight of 5.133 kDa.

Whey-based sports supplements: Heat damage and protein breakdown after in vitro gastrointestinal digestion

This study was aimed to evaluate the effect of heat damage on the release of total amino acids (AA), essential AA (EAA), branched-chain AA (BCAA) and bioactive peptides following in vitro static simulated gastrointestinal digestion (SGID) of four commercial whey-protein based sports supplements. The extent of protein glycation and denaturation was evaluated through the determination of the content of furosine and soluble whey proteins. The strongest protein breakdown (41.3 %) and the highest release of AA, EAA and BCAA (36.20, 27.78, and 11.30 g/100 g protein, respectively) was observed in the sports supplement characterised by the lowest (52.5 %) level of soluble whey proteins; whereas the protein glycation had a negligible impact on the studied parameters. The SGID also led to the release of several peptides with various reported bioactivities that may be beneficial to sports activity.

Effect of thermosonication on the bioactive peptide profile, volatile compounds, and fatty acid profile of Minas Frescal cheese

This study investigated the effect of thermosonication (TS) of milk on the bioactive peptide profile, fatty acid composition, and volatile compounds of Minas Frescal cheese. Five cheese formulations were prepared: raw milk (Control), pasteurized milk (High-Temperature Short-Time or HTST) (72–75 °C/15 s), and milk treated by TS at nominal powers of 160 W (TS160), 400 W (TS400), and 640 W (TS640). The fatty acid profile and health indices did not change significantly after HTST or TS. TS, mainly TS400 treatment, increased the number of bioactive peptides with antihypertensive, antioxidant, immunomodulatory, and antimicrobial activities and promoted the formation of unique volatile organic compounds, mainly from the ester and fatty acid groups. In conclusion, TS can be considered by the dairy industry as an interesting alternative for manufacturing Minas Frescal cheese, resulting in products with greater functional potential and unique volatile compounds and keeping the fatty acid profile unchanged.

A novel series of metazoan L/D peptide isomerases

The function of endogenous cell-cell signaling peptides rely on their interactions with cognate receptors, which in turn are influenced by the peptides' structures, necessitating a comprehensive understanding of the suite of post-translational modifications (PTMs) of the peptide. Herein, we report the initial characterization of putative peptide isomerase enzymes extracted from R. norvegicus, A. californica, and B. taurus tissues. These enzymes are both tissue and substrate-specific across all three organisms. Notably, the lungs of the mammalian species, and the central nervous system of the mollusk displayed the highest isomerase activity among the examined tissues. In-vitro enzymatic conversion was observed for several endogenous peptides, such as the tetrapeptide GFFD in A. californica, and mammalian neuropeptide FF in R. norvegicus and B. taurus. To understand their mode of action, we explored the effects of several inhibitors on these enzymes, which suggests common active site residues. While further characterization of these enzymes is required, the investigations emphasize a widespread and overlooked enzyme activity related to the creation of bioactive peptides.

A novel ACE inhibitory peptide from Pelodiscus sinensis Wiegmann meat water-soluble protein hydrolysate

Pelodiscus sinensis meat is a nutritional food and tonic with angiotensin-converting enzyme (ACE) inhibitory activities. To identify the bioactive substances responsible, several bioinformatics methods were integrated to enable a virtual screening for bioactive peptides in proteins identified within a water-soluble protein fraction of Pelodiscus sinensis meat by Shotgun proteomics. The peptides were generated from the identified proteins by in silico proteolysis using six proteases. A comparison of the numbers of proteins suitable for digestion with each enzyme and the iBAQ (intensity-based absolute quantification) values for these proteins revealed that bromelain and papain were the most suitable proteases for this sample. Next, the water solubility, toxicity, and ADMET (absorption/distribution/metabolism/excretion/toxicity) properties of these peptides were evaluated in silico. Finally, a novel ACE inhibitory peptide IEWEF with an IC50 value of 41.33 µM was identified. The activity of the synthesized peptide was verified in vitro, and it was shown to be a non-competitive ACE inhibitor. Molecular docking revealed that IEWEF could tightly bind to C-ACE, and N-ACE with energies less than 0 kJ mol−1, and the peptide IEWEF can form hydrogen bonds with C-ACE and N-ACE respectively. These results provide evidence that bioactive peptides in the water-soluble protein fraction account for (at least) some of the ACE inhibitory activities observed in Pelodiscus sinensis meat. Furthermore, our research provides a workflow for the efficient identification of novel ACE inhibitory peptides from complex protein mixtures.

Comprehensive characterization of bioactive peptides in rice bran protein hydrolysates: A multi‐platform approach for metabolomic profiling, identification, and molecular docking analysis

AbstractBackground and ObjectivesTo optimize the utilization of rice by‐products, the rice bran protein hydrolysate (RBPH) was subjected to a process of separation and purification using ultrafiltration and reversed‐phase high‐performance liquid chromatography (RP‐HPLC). Subsequently, the identification of peptide sequences was carried out using mass spectrometer hybrid quadrupole‐time‐of‐flight and nontargeted metabolomic profiling done using UHPLC‐QTOF‐IMS profiling to identify antioxidant and antihypertensive amino acids.FindingsThree novel bioactive peptides, namely, STCCK, FMKSK, and KICILVFTLTTC, were identified within RBPH through enzymatic digestion using alcalase, pepsin, and trypsin. These peptides showed significant antioxidant activity and angiotensin‐converting enzyme (ACE) inhibitory activity. Molecular docking analyses elucidated various interaction mechanisms between these peptides and the ACE receptor protein, including hydrogen bonding and hydrophobic interactions. This suggested that the peptides effectively suppress ACE by forming hydrogen bonds with the active pockets of human ACE with a high affinity.ConclusionIn summary, peptides derived from rice bran protein exhibited distinguished antihypertensive and antioxidant properties, underscoring their potential for valuable utilization in addressing utilization of rice by‐products.Significance and NoveltyThe study advances scientific knowledge and offers practical solutions for health improvement and sustainable agriculture.

Introducing Bacillus natto and Propionibacterium shermanii into soymilk fermentation: A promising strategy for quality improvement and bioactive peptide production during in vitro digestion

Herein, the texture properties, polyphenol contents, and in vitro protein digestion characteristics of soymilk single- or co-fermented by non-typical milk fermenter Bacillus natto (B. natto), Propionibacterium freudenreichii subsp. shermanii (P. shermanii), and traditional milk fermenter were evaluated. Co-fermenting procedure containing B. natto or P. shermanii could raise the amounts of gallic acid, caffeic acid, and GABA when compared to the unfermented soymilk. Co-fermented soymilk has higher in vitro protein digestibility and nutritional protein quality. Through peptidomic analysis, the co-work of P. shermanii and Lactobacillus plantarum (L. plantarum) may release the highest relative percentage of bioactive peptides, while the intervention of B. natto and Streptococcus thermophilus (S. thermophilus) resulted in more differentiated peptides. The multi-functional bioactive peptides were mainly released from glycine-rich protein, β-conglycinin alpha subunit 1, and ACB domain-containing protein. These findings indicated the potential usage of B. natto/S. thermophilus or P. shermanii/L. plantarum in bio-enhanced soymilk fermentation.

Releasing angiotensin I‐converting enzyme inhibitory (ACE‐I) peptides by Yamadazyma spp. in non‐fat milk

SummaryThe objectives of this study were to analyse the impact of both temperature and different isolates on microbial protease production ability and to examine the hypertensive effect of bioactive peptides (BAPs) that inhibit the angiotensin I‐converting enzyme released by fermentation of non‐fat milk. First, the ability of several Yamadazyma spp. isolates, which were previously isolated and identified from several sources, was screened in terms of the production of proteolytic enzymes at 15 and 25 °C. The effect of temperature on proteolysis activity of selected isolates was considerable, and incubation at 25 °C was favourable for protease production. Besides, combinations of three different isolates showed remarkable proteolytic activity during the incubation periods of 24, 48 and 72 h. The highest angiotensin I‐converting enzyme inhibitory (ACE‐I) activity was detected for the combination Yamadazyma spp. BO10 and B514‐1, with an inhibition of 92.5%. The partial purification of peptides by ultrafiltration (cut‐off 10 kDa) has no crucial impact on ACE‐I activity, and further purification might improve their effectiveness. The implications of fermentation with co‐culture may have symbiotic potential to increase the antihypertensive effect of the product. Therefore, these results suggest that Yamadazyma spp. may be used to produce functional products or bioactive peptides presenting health‐promoting attributes.

Blood-supplementing effect of low molecular weight peptides of E-Jiao on chemotherapy-induced myelosuppression: evaluation of pharmacological activity and identification of bioactive peptides released in vivo.

Background: Equus asinus L. [Equidae; Asini Corri Colla] (donkey-hide gelatin, E-Jiao) is a traditional Chinese medicine renowned for its exceptional blood-supplementing effect. However, the specific components that contribute to its efficacy remain elusive. This study aimed to demonstrate that peptides are responsible for E-Jiao's blood-supplementing effect and to explore the specific peptides contributing to its efficacy. Methods: The low molecular weight peptides of E-Jiao (LMEJ) were obtained using an in vitro digestion method. LMEJ and peptides in the rat bloodstream were characterized by peptidomics analysis. The blood-supplementing effect of LMEJ was assessed using blood-deficient zebrafish and mouse models. The effect of the peptides detected in rat blood was evaluated using the same zebrafish model, and network pharmacology analysis was performed to investigate the underlying mechanisms. Results: A total of 660 unique peptides were identified within LMEJ. Both E-Jiao and LMEJ significantly alleviated myelosuppression in mice but only LMEJ attenuated myelosuppression in zebrafish. After the administration of E-Jiao to rats, 67E-Jiao-derived peptides were detected in the bloodstream, 41 of which were identical to those identified in LMEJ. Out of these 41 peptides, five were synthesized. Subsequent verification of their effects revealed that two of them were able to alleviate myelosuppression in zebrafish. Network pharmacology study suggested that E-Jiao may exert a blood-supplementing effect by regulating signaling pathways such as JAK-STAT, IL-17 and others. These results indicated that peptides are at least partially responsible for E-Jiao's efficacy. Conclusion: This study provides a crucial foundation for further exploration of the bioactive components of E-Jiao.

Galanin Coordinates Macrophage-Associated Fibro-Inflammatory Response and Mitochondrial Integrity in Myocardial Infarction Reperfusion Injury.

Myocardial infarction activates an intense fibro-inflammatory reaction that is essential for cardiac remodeling and heart failure (HF). Bioactive peptide galanin plays a critical role in regulating cardiovascular homeostasis; however, its specific functional relevance in post-infarction fibro-inflammatory reprogramming remains obscure. Here, we show that galanin coordinates the fibro-inflammatory trajectory and mitochondrial integrity in post-infarction reperfusion injury. Aberrant deposition of collagen was associated with a marked increase in CD68-positive macrophage infiltration in cardiac tissue in mice subjected to myocardial ischemia/reperfusion (I/R) for 14 days compared to sham controls. Furthermore, we found that the myocardial expression level of a specific marker of M2 macrophages, CD206, was significantly down-regulated in I/R-challenged mice. In contrast, galanin treatment started during the reperfusion phase blunted the fibro-inflammatory responses and promoted the expression of CD206 in I/R-remodeled hearts. In addition, we found that the anti-apoptotic and anti-hypertrophic effects of galanin were associated with the preservation of mitochondrial integrity and promotion of mitochondrial biogenesis. These findings depict galanin as a key arbitrator of fibro-inflammatory responses to cardiac I/R injury and offer a promising therapeutic trajectory for the treatment of post-infarct cardiovascular complications.

A synthetic bioactive peptide of the C-terminal fragment of adhesion protein Fibulin7 attenuates the inflammatory functions of innate immune cells in LPS-induced systemic inflammation.

Systemic inflammation is associated with improper localization of hyperactive neutrophils and monocytes in visceral organs. Previously, a C-terminal fragment of adhesion protein Fibulin7 (Fbln7-C) was shown to regulate innate immune functionality during inflammation. Recently, a shorter bioactive peptide of Fbln7-C, FC-10, via integrin binding was shown to reduce ocular angiogenesis. However, the role of FC-10 in regulating the neutrophils and monocyte functionality during systemic inflammatory conditions is unknown. The study sought to explore the role of FC-10 peptide on the functionality of innate immune cells during inflammation and endotoxemic mice. Neutrophils and monocytes were isolated from healthy donors and septic patient clinical samples and Cell adhesion assay was performed using a UV spectrophotometer. Gene expression studies were performed using qPCR. Protein level expression was measured using ELISA and flow cytometry. ROS assay, and activation markers analysis in vitro, and in vivo were done using flow cytometry. Cells were stimulated with LPS (100ng/mL) and studied in the presence of peptides (10μg, and 20μg/mL) in vitro. In an in vivo study, mice were administered with LPS (36.8mg/kg bw) and peptide (20μg). This study demonstrates that human neutrophils and monocytes adhere to FC-10 via integrin β1, inhibit spreading, ROS, surface activation markers (CD44, CD69), phosphorylated Src kinase, pro-inflammatory genes, and protein expression, compared to scrambled peptide in cells isolated from healthy donors and clinical sample. In line with the in vitro data, FC-10 (20μg) administration significantly decreases innate cell infiltration at inflammatory sites, improves survival in endotoxemia animals & reduces the inflammatory properties of neutrophils and monocytes isolated from septic patients. FC-10 peptide can regulate neutrophils and monocyte functions and has potential to be used as an immunomodulatory therapeutic in inflammatory diseases.

Efficacy of a Food Supplement Containing Lactobacillus acidophilus LA14, Peptides, and a Multivitamin Complex in Improving Gastroesophageal Reflux Disease-Related Outcomes and Quality of Life of Subjects Showing Mild-to-Moderate Gastroesophageal Reflux Disease.

Dietary interventions represent an interesting alternative to pharmacological treatments for improving the quality of life (QoL) of subjects suffering from gastroesophageal reflux disease (GERD). This randomized, double-blind, placebo-controlled study aimed to evaluate the efficacy of a food supplement (FS) containing a probiotic strain, bioactive peptides, and vitamins in relieving heartburn/dyspeptic symptoms in subjects with mild-to-moderate GERD. Fifty-six adult participants were randomly assigned to receive the placebo or the active FS for 28 days. Subjects were asked to record daily the frequency and intensity of heartburn episodes and the intake of over- the-counter (OTC) medications. GERD-QoL and self-assessment questionnaires were also completed every two weeks and at the end of the treatment, respectively. FS was effective in achieving a progressive and significant reduction of heartburn frequency and severity, with an intergroup significant difference at the end of the treatment period. FS group also reported a reduction in the OTC medication intake, whereas placebo administration did not modify the OTC intake. Results from the QoL and self-assessment questionnaires showed that FS administration achieved a progressive and statistically significant intragroup and intergroup improvement in the QoL score and a higher positive response with respect to the placebo treatment.

Bioprospecting and marine ‘omics’: surfing the deep blue sea for novel bioactive proteins and peptides

The vast biological and biochemical diversity of the global ocean is the driver behind marine bioprospecting for novel bioproducts. As Marine Biotechnology is gaining momentum as one of the main pillars of the ‘Brue Growth’ revolution, the ability to screen for novel compounds of interest in species with little or no genomic resources is paramount. With this respect, proteins, which are easily metabolised, can be synthetised using convenient DNA recombinant methods and can easily be modified to better meet the needs of human society, making them prized targets. Evidently, proteins that hold natural bioactivity and specificity such as toxins and other venom components, have long captured the focus of biotechnologists, leading to the merger between environmental omics and toxinology termed as ‘venomics’. Indeed, bioactive proteins such as conopeptides, conotoxins, turripeptides and others are long deemed important subjects of research. Even though current mainstream paradigms set the focus on secondary metabolites from marine organisms, transcriptomics and proteomics approaches and their combination are rising strategies for screening for thousands of proteins and peptides in non-conventional biological models, emphasising, but not limited to, marine invertebrate animals due to their abundance, biodiversity and uncanny biochemical strategies to cope with selective pressure in literally every known marine habitat. Untargeted approaches, such as RNA-Seq – based transcriptomics and tandem mass spectrometry – based proteomics, can circumvent limitations related with absent or reduced genomic annotation. The present review will outline the main contributions of ‘omics’ and computational approaches for bioprospecting for proteinaceous marine bioactives. Despite the relatively low number of ‘omics’ studies with the main purpose of discover novel compounds, there is already important literature showcasing pipelines and approaches for revolutionising the exploration of the ocean.

Evaluation of antioxidant, antimicrobial, and bioactive properties and peptide sequence composition of Malatya apricot kernels.

This study used four different apricot (Prunus armeniaca) kernels cultivated in Malatya during two consecutive years. The varieties were Hacihaliloglu, Hasanbey, Kabaasi, and Zerdali. The physicochemical properties of the kernels were determined, and the bioactive content of the kernels was evaluated using kernel hydrolysates prepared using trypsin. With regard to the physicochemical properties of the kernels, the dry matter ratio and protein content were the highest in the Hacihaliloglu variety; the ash ratio was the highest in the Kabaasi variety, and the free oil ratio was the highest in the Hasanbey variety. The bioactive compound content changed according to kernel variety. Angiotensin-converting enzyme inhibitors activity was found to be the highest in the Hacihaliloglu and Hasanbey varieties, which had the lowest amygdalin content, and Zerdali had the highest amygdalin content. The antioxidant and antimicrobial effects of the kernels varied, with Hasanbey and Kabaasi generally having the highest content in both analyses. Moreover, a concentration of 20 mg mL-1 of the hydrolysate was determined to have a destructive effect for the microorganisms used in this study. The storage protein of the kernels, except Hacihaliloglu, was found to be Prunin 1, with the longest matching protein chain in the kernels being R.QQQGGQLMANGLEETFCSLRLK.E. The results suggest that the peptide sequences identified in the kernels could have antihypertensive, antioxidative, and Dipeptidyl peptidase IV (DPP-IV)inhibitory effects. Consequently, apricot kernels show potential for use in the production of functional food products. Of the kernels evaluated in this study, Hacihaliloglu and Hasanbey were deemed the most suitable varieties due to their higher bioactive content and lower amygdalin content. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Transcriptome profiling of the posterior salivary glands of the cuttlefish Sepia officinalis from the Portuguese West coast

Cephalopods like octopuses and cuttlefishes are known to secrete a ‘toxic saliva’ to inject into their prey, especially crustaceans since the XIX century. However, only in the mid-XX century were the first coleoid-specific toxins successfully isolated. Motivated by the growing interest on the global ocean as an almost inexhaustible source of novel bioactive compounds, we used RNA-Seq – based transcriptomics and de novo assembly of transcriptomes to screen the posterior salivary glands of Sepia officinalis (the common cuttlefish) from the Portuguese West coast for toxins and other bioactive proteins and peptides. Supported by microanatomical analyses, the posterior salivary glands constitute indeed the ‘venom gland’ whereas the more elusive anterior salivary glands (embedded in the buccal mass) are responsible for the production of mucin-rich saliva that is effectively the vehicle that transports the toxins as the venom is injected into the prey. Indeed, the transcriptomic profiling suggests that the cuttlefish venom is complex mixture of bioactive proteins, among which neurotoxins are major players, together with enzymes whose function is to digest the extracellular matrix to facilitate diffusion of the toxins. Nonetheless, by comparing with previous RNA-Seq data obtained from S. officinalis collected from other biogeographical areas, it may be suggested that significant inter-populational variation in venom composition can occur, which may potentially increase the span of bioactives secreted by these animals. We isolated and validated the full coding sequences for three important toxins, a cysteine-rich venom protein (CRVP), a venom insulin (VIns) and a cephalotoxin (CTX). The toxins seem to be relatively conserved among coleoids but diverging from other venomous mollusks such as cone snails. Their properties as potent modulators of glucose (in the case of VIns) and as potential neurotoxins (like CRVP and CTX) can render them primer targets for drug development.

His-Tagging: Exploring Precise Chemical Modification of Histidine-Containing Bioactive Peptide Sequences

AbstractThe modification of biomolecules, particularly peptides, has garnered considerable attention from researchers, effectively serving as a connection between chemistry and biology. The modification of peptides can facilitate, among others, the generation of peptide drugs, antibody–drug conjugates, and probes for molecular imaging. Herein, we have carefully curated reactions and chemical transformations of bioactive peptide sequences equipped with histidine amino acids that are conducive for biological applications. This Account also highlights strategies for the chemical modification of histidine that might capture the imagination of both peptide researchers and synthetic chemists.1 Introduction2 Histidine Modification in Bioactive Peptides and Proteins3 Remote Bioactive Peptides and Protein Modification Adjacent to Histidine4 Conclusions and Future Directions

Beneficial effects of bioactive peptides extracted from Spirulina platensis and Gracilaria gracilis algae on bone regeneration/osteogenic differentiation of mesenchymal stem cells

Mesenchymal stem cells are used in the treatment of many diseases, particularly in the repair of bone injuries. Algae with various medicinal applications are considered important natural resources. There is limited research on the effects of bioactive peptides from algae extraction on mesenchymal stem cells. In this study the impact of bioactive proteins, protein lysates and peptide fractions (<3, <30 and <50 kDa) isolated from two algae species, Spirulina platensis and Gracilaria gracilis on the proliferation and osteogenic differentiation of human amniotic mesenchymal stem cells (hAMSCs) was investigated. The proteins were extracted ant hydrolyzed with trypsin enzyme to create peptides, which were then separated by ultrafiltration. hAMSCs were exposed to different concentrations of bioactive compounds (100, 300, 500 and 700 µg/ml) for varying time periods. Cell proliferation was assessed using the with 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and to evaluate differentiation into bone tissue, the amount of mineral deposition was measured with alizarin red staining, and alkaline phosphatase enzyme activity was determined using a colorimetric method. The expression of Runx2, Osteocalcin, and β-Catenin genes expression was analyzed using RT-qPCR on days 7, 14 and 21 post-treatment. The results indicated that the <3 kDa peptide fraction of S. platensis and G. gracilis had no cytotoxic effects, increased cell proliferation at a concentration of 300 μg/ml, and enhanced the expression of osteogenic marker genes, alkaline phosphatase enzyme a activity, and calcium deposition in the extracellular matrix. In general, fractions that show positive effects on hAMSC differentiation have the potential to treat bone defects and promote osteoregeneration.

Exploring the response of PACAP on thermal endurance of F-actin by differential scanning calorimetry

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a bioactive peptide known for its diverse effects on the nervous system. While numerous studies have demonstrated the neuroprotective properties of PACAP, its role in tissue regeneration and potential as a therapeutic agent remain to be fully understood. Specifically, the understanding of PACAP’s impact on cytoskeletal dynamics, particularly the organization and disorganization of actin filament networks, is limited due to the scarcity of in vitro studies in this area. Additionally, the interaction between PACAP and actin has been minimally explored, and the influence of PACAP on the thermal stability of actin is completely unknown. To address these gaps, the current study aimed to investigate the impact of different forms and fragments of PACAP on the thermal denaturation and renaturation of Ca2+-F-actin using a differential scanning calorimetry (DSC) approach. Our primary objective was to determine whether PACAP modulates the thermal stability of Ca2+-F-actin and establish a temperature-dependent pattern of any structural alterations that may occur as a result of PACAP interaction. Two PACAP forms exist in vivo: the 38 amino acid length PACAP38 and the PACAP27, the latter truncated at the C-terminal. Both in the PACAP38 + Ca2+-F-actin and in the PACAP6-38 + Ca2+-F-actin mixtures, the DSC scans exhibited a significant decrease of actin denaturation temperature compared to the control; however, the PACAP27 + Ca2+-F-actin and PACAP6-27 + Ca2+-F-actin revealed no remarkable differences compared to the actin control sample. The calorimetric enthalpy of the truncated PACAP27 and PACAP6-27 + actin mixture also followed the tendencies mentioned above. Thus, in PACAP27 and PACAP6-27 mixture, there was no change in the denaturation temperature of actin, and no significant ΔHcal was observed. Through this research, we sought to elucidate the underlying mechanisms of PACAP’s effects on actin dynamics using thermal de- and renaturation cycles.

Bioactive peptides released by lactic acid bacteria fermented pistachio beverages

Fruit and vegetable are the raw materials for many popular fermented beverages with potential health benefits. In the present study, a novel pistachio beverage fermented with selected strains of lactic acid bacteria belonging to the species Leuconostoc pseudomesenteroides and Companilactobacillus paralimentarius was produced, and the extent of proteolysis was evaluated. Physico-chemical and microbiological analyses, together with peptidomics and proteomics, were carried out on the beverage after 24 h of fermentation, using both the non-inoculated and chemically acidified beverage as controls. Amino acid sequence of hundreds of peptides mainly released from 2S albumin, 11S and 7S globulin were characterized. The number and frequency of identified peptides were higher in beverage started with Leuconostoc pseudomesenteroides, followed by Companilactobacillus paralimentarius and acidic beverage. These results suggest that, in addition to endogenous proteases active at acidic pH, the proteolytic system of LAB directly participated to peptide degradation to some extent. According to the BIOPEP database, a group of 31 peptides were potentially bioactive, and primarily associated with antioxidative properties, ACE and DPP-IV inhibition. The beverage started with Leuconostoc pseudomesenteroides showed the highest amount and number of bioactive peptides. This study lays the foundations for the design of novel pistachio-fermented beverage with potential health properties.