Peptide Fractions Research Articles

Characteristics of Umami Taste of Soy Sauce Using Electronic Tongue, Amino Acid Analyzer, and MALDI-TOF MS.

The objective of this study was to investigate the umami characteristics of soy sauce using electronic tongue evaluation and amino acid composition and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. The soy sauce peptides were isolated from soy sauce using XAD-16 macroporous resin combined with ethanol solution. The results showed that the soy sauce peptide fraction eluted by 60% ethanol (SS-60%) exhibited a prominent umami taste, and the umami scores were highly positively correlated with the amino acid nitrogen contents of soy sauces. The umami scores of SS-60% were significantly positively correlated with the contents of free amino acids. Especially, Phe showed the highest positive correlation with the umami scores. In addition, five characteristic ion peaks with m/z at 499, 561, 643, 649, and 855 were identified in the peptide mass fingerprinting. Therefore, this study provides new insights into the umami characteristics for the taste evaluation and reality identification of soy sauce.

Effect of ripening time on the content of bioactive peptides and fatty acids profile of Artisanal Coalho cheese.

The present study aimed to investigate the influence of ripening on the physicochemical, microbiological aspects, and fatty acid profile of Artisanal Coalho Cheeses and to detect if there are peptides with bioactive potential in their composition. Artisanal Coalho Cheese samples were kindly provided by a dairy farm located in Brazil in the Rio Grande do Norte state. A completely randomized design was adopted, with four maturation periods (0, 30, 45, and 60 days). Physicochemical traits (pH, total solids, moisture, non-fat solids, fat in total solids, protein, ash, fatty acid profile) and microbiological characterization (Salmonella sp, Listeria monocytogenes, total and thermotolerant coliforms, Staphylococcus aureus) were analyzed on cheese samples. Additionally, assays were performed for antioxidant and antihypertensive bioactivity through ACE and antimicrobial inhibition of the peptides extracted from the samples. There was a linear increase in total solids and ash content and a decrease in moisture content with increasing maturation time. The matured cheese samples had a lower pH than fresh Artisanal Coalho Cheese. Twenty-seven fatty acids were identified in the cheeses: 15 saturated, 07 monounsaturated, and 05 polyunsaturated, with a linear reduction of essential fatty acids (n6 and n3) during maturation. The microbiological quality of the cheeses was satisfactory, with an absence of undesirable bacteria in 92% of the cheese samples. Water-soluble peptide fractions from all periods tested showed antioxidant and antihypertensive potential with ACE control, and the maturation process potentiated these capacities, with a decline in these activities observed at 60 days. The antimicrobial activity against Gram-positive and Gram-negative bacteria increased with maturation, reaching better results until 60 days. The maturation process on wooden planks in the periods of 30, 45, and 60 days allows the production of Artisanal Coalho Cheese of an innovative character, safe to consumers from the microbiological point of view, with differentiated physicochemical and functional characteristics and good quality of lipid fraction compared to fresh cheese, enabling the addition of value to the dairy chain.

Response to therapy with tafamidis 61 mg in patients with cardiac transthyretin amyloidosis: real-world experience since approval

Aims Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive disease that causes heart failure due to amyloid fibril deposition. Tafamidis was approved as the first causal treatment in 2020. We here report on real-world data in patients treated with tafamidis for at least 12 months according to the recently defined European Society for Cardiology (ESC) consensus criteria for disease progression. Methods and results Three hundred and eight wildtype and 31 hereditary ATTR-CM patients were prospectively enrolled after first diagnosis of ATTR-CM and initiation of tafamidis 61 mg once daily treatment. After 12 months, significant deterioration in Karnofsky Index, estimated glomerular filtration rate (eGFR), N-terminal brain natriuretic peptide (NT-proBNP), septum thickness and left ventricular ejection fraction (LVEF) could be observed, significant disease progression was only detected in 25 patients (9%) using ESC consensus criteria. Mean survival time was 37 months with no differences between responders and non-responders. NT-proBNP was the only independent predictor for poor therapy response (p = .008). Conclusions The majority of patients showed no significant disease progression according to the ESC consensus criteria after 12 months of therapy with tafamidis. However, at 12 months, treatment response based on the ESC consensus criteria was not associated with improved survival. Moreover, higher levels of NT-proBNP at diagnosis of ATTR-CM appears to predict poorer treatment response, confirming that timely initiation of therapy is advantageous.

Comparative studies on composition of feed additives for juvenile fish produced with bioconversion of fish raw materials

Technology of feed additive for fry feeding in fish farms is developed to provide both important nutrients (proteins, lipids, etc.) and optimal peptide composition of protein that is achieved using proteolysis of raw materials under certain conditions. For this purpose, enzymatic hydrolysis of substandard small-sized frozen pollock was used. The rational duration of the hydrolysis process was 60 min. that provided the degree of protein hydrolysis of 26–28 %. The experimental fermentolysate was concentrated to a water content of 3–4 % and presented as a feed additive TINRO-60. This product is compared with other feed additives (dried fermentolysates) produced in Russia from fish raw materials using bioconversion, such as Biomarin, Bioprom and Vakhob. General chemical composition of tested products was determined by standard methods of analytical chemistry; composition and content of fatty acids — by gas-liquid chromatography; microand macroelements, as well as toxic metals — by atomic absorption spectrophotometry; fractional composition of proteins and peptides — by high pressure gel permeation chromatography; amino acid composition — by ion exchange chromatography on a high-speed analyzer. All tested samples contain similar amount of the main feed component — protein substances. The quantitative ratio of peptide fractions is also comparable, the sum of the most active fractions (MW 0.1−10.0 kDa) in TINRO-60 and Biomarin is close to their level in tissues of Artemia, natural food for fish fry. The content of essential amino acids, EPA and DHA is significant in Biomarin, TINRO-60 and Bioprom, but almost twice lower in Vakhob. Analysis of mineral composition showed that bioconversion into dry fermentolysates does not cause concentration of toxic elements. High quality of the protein feed additive TINRO-60 produced by bioconversion of nonstandard fish raw materials under certain conditions is proved.

Identification and Molecular Mechanism of Anti-inflammatory Peptides Isolated from Jack Bean Protein Hydrolysates: in vitro Studies with Human Intestinal Caco-2BBe Cells

Jack bean (JB), Canavalia ensiformis (L.) DC, is a commonly cultivated legume in Indonesia. It is rich in protein, which can be hydrolyzed, making it potentially a good source of bioactive peptides. Intestinal inflammation is associated with several diseases, and the production of interleukin-8 (IL-8) in intestinal epithelial cells induced by tumor necrosis factor (TNF)-α has an important role in inflammatory reaction. The present study investigated the anti-inflammatory effects of peptides generated from enzymatic hydrolysis of JB protein on human intestinal Caco-2BBe cells. Additionally, in silico approaches were used to identify potential bioactive peptides. JB protein hydrolysate (JBPH) prepared using pepsin and pancreatin reduced the IL-8 expression at protein and mRNA levels in Caco-2BBe cells stimulated with TNF-α. Immunoblot analysis showed that the JBPH reduced the TNF-α-induced phosphorylation of c-Jun-NH(2)-terminal kinase, nuclear factor kappa B (NF-κB), and p38 proteins. Anti-inflammatory activity was observed in the 30% acetonitrile fraction of JBPH separated on a Sep-Pak C18 column. An ultrafiltration method revealed that relatively small peptides (< 3 kDa) had a potent inhibitory effect on the IL-8 production. Purification of the peptides by reversed-phase and anion-exchange high performance chromatography produced three peptide fractions with anti-inflammatory activities. A combination of mass spectrometry analysis and in silico approaches identified the potential anti-inflammatory peptides. Peptides derived from JB protein reduces the TNF-α-induced inflammatory response in Caco-2BBe cells via NF-κB and mitogen-activated protein kinase signaling pathways. Our results may lead to a novel therapeutic approach to promote intestinal health.

Optimization of enzymatic production of anti-skin aging biopeptides from white sorghum [Sorghum bicolor (L) Moench] grain

Recently, kafirins from white sorghum [Sorghum bicolor (L) Moench] grain have shown promise as a source of biopeptides with anti-skin aging effects (anti-inflammatory, antioxidant, and inhibition of photoaging-associated enzymes). This study employed response surface methodology (RSM) to optimize the extraction and enzymatic hydrolysis of kafirins (KAF) for the production of peptides with anti-skin aging properties. The optimization of conditions (reaction time and enzyme/substrate ratio) for liquefaction with α-amylase and hydrolysis of KAF with alcalase was performed using 32 complete factorial designs. Subsequently, ultrafiltered peptide extracts were obtained with molecular weights of 1–3 kDa (KAF-UF3) and lower than 1 kDa (KAF-UF1), which mainly contain hydrophobic amino acids (proline, leucine, isoleucine, phenylalanine, and valine) and peptide fractions with molecular weights of 0.69, 1.14, and 1.87 kDa. Consequently, the peptide extracts protected immortalized human keratinocytes (HaCaT cells) from ultraviolet B radiation (UVB)-induced damage by preventing the decrease and/or restoring the activity of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px)]. Furthermore, KAF-UF3 and KAF-UF1 inhibited (20–29%) elastase and collagenase overactivity in UVB-exposed murine fibroblasts (3T3 cells). Thus, KAF-UF3 and KAF-UF1 exhibited behavior similar to that observed with glutathione (GSH), suggesting their potential as functional peptide ingredients in skincare products.

Therapeutic implications of flaxseed peptides and bioactive components against various diseases

Flaxseed (Linum usitatissimum L.) is nutritionally loaded with alpha-linolenic acid, lignans, Secoisolariciresinol diglucoside, soluble fiber, proteins, and bioactive peptides that implicate numerous therapeutic and health-boosting effects. The current review article aimed to comprehensively summarize the essential components of flaxseed along with their therapeutic role against different physiological disorders. Flaxseed is used in different forms including oil, powder, extract and whole seed where polyunsaturated fatty acids such as alpha-linolenic acid are significantly abundant in flaxseed oil. Most of the fiber in flaxseed comes from the hull, which contains 9 % insoluble fiber and 20 % soluble fiber. Soluble fibers contain neutral glucose and acidic polysaccharides, while insoluble fibers consist of lignin, cellulose, and acid detergent fiber. Bioactive peptides present in flaxseeds have gained acceptance as health-promoting medicines due to their useful amino acid profile. Studies revealed that flaxseed is rich in 40 % protein and bioactive peptides which are made up of 20 amino acids and two (dipeptides) residues with a molecular mass of 0.4–2 kDa. Enzymatic hydrolysis is a successful process for producing and releasing bioactive peptides which are obtained from the wastes of flaxseed oil after extraction. Peptide fractions (1 kDa) obtained after ultrafiltration of alcalde-hydrolyzed flaxseed are used in various applications, including as a food source and nutraceutical. Flaxseed has become a well-acknowledged functional food due to its physiological properties, such as anti-diabetic, antibacterial, angiotensin-converting enzyme inhibition, and antioxidant capacity owing to the presence of peptides, SDG, lignin, ALA and fiber. In addition, these bioactive fractions of flaxseed in various forms tend to reduce and prevent arthritis, hyperlipidaemias, cardiovascular diseases, osteoporosis, neurological disorders, and cancers of many types. Hence, flaxseed is evident to be a versatile functional food that elicits several physiological disorders and ailments due to its mechanically active compounds. Further research is required about the bioavailability of active components and their broad spectrum application in humans for health promotion and disease prevention.

Antibacterial Properties of Peptide and Protein Fractions from Cornu aspersum Mucus.

The discovery and investigation of new natural compounds with antimicrobial activity are new potential strategies to reduce the spread of antimicrobial resistance. The presented study reveals, for the first time, the promising antibacterial potential of two fractions from Cornu aspersum mucus with an MW < 20 kDa and an MW > 20 kDa against five bacterial pathogens-Bacillus cereus 1085, Propionibacterium acnes 1897, Salmonella enterica 8691, Enterococcus faecalis 3915, and Enterococcus faecium 8754. Using de novo sequencing, 16 novel peptides with potential antibacterial activity were identified in a fraction with an MW < 20 kDa. Some bioactive compounds in a mucus fraction with an MW > 20 kDa were determined via a proteomic analysis on 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and bioinformatics. High homology with proteins and glycoproteins was found, with potential antibacterial activity in mucus proteins named aspernin, hemocyanins, H-lectins, and L-amino acid oxidase-like protein, as well as mucins (mucin-5AC, mucin-5B, mucin-2, and mucin-17). We hypothesize that the synergy between the bioactive components determined in the composition of the fraction > 20 kDa are responsible for the high antibacterial activity against the tested pathogens in concentrations between 32 and 128 µg/mL, which is comparable to vancomycin, but without cytotoxic effects on model eukaryotic cells of Saccharomyces cerevisiae. Additionally, a positive effect, by reducing the levels of intracellular oxidative damage and increasing antioxidant capacity, on S. cerevisiae cells was found for both mucus extract fractions of C. aspersum. These findings may serve as a basis for further studies to develop a new antibacterial agent preventing the development of antibiotic resistance.

Reconstitution of peripheral blood T cell receptor β immune repertoire in immune checkpoint inhibitors associated myocarditis

PurposeImmune checkpoint inhibitors (ICIs)-associated myocarditis was a rare yet severe complication observed in individuals undergoing immunotherapy. This study investigated the immune status and characteristics of patients diagnosed with ICIs- associated myocarditis.MethodsA total of seven patients diagnosed with ICIs-associated myocarditis were included in the study, while five tumor patients without myocarditis were recruited as reference controls. Additionally, 30 healthy individuals were recruited as blank controls. Biochemical indices, electrocardiogram, and echocardiography measurements were obtained both prior to and following the occurrence of myocarditis. High-throughput sequencing of T cell receptor (TCR) was employed to assess the diversity and distribution characteristics of TCR CDR3 length, as well as the diversity of variable (V) and joining (J) genes of T lymphocytes in peripheral blood.ResultsIn the seven patients with ICIs-associated myocarditis, Troponin T (TNT) levels exhibited a significant increase following myocarditis, while other parameters such as brain natriuretic peptide (BNP), QTc interval, and left ventricular ejection fraction (LVEF) did not show any significant differences. Through sequencing, it was observed that the diversity and uniformity of CDR3 in the ICIs-associated myocarditis patients were significantly diminished. Additionally, the distribution of CDR3 nucleotides deviated from normality, and variations in the utilization of V and J gene segments.ConclusionThe reconstitution of the TCR immune repertoire may play a pivotal role in the recognition of antigens in patients with ICIs-associated myocarditis.

Angiotensin-I-converting enzyme and renin inhibitions by antioxidant shrimp shell protein hydrolysate and ultrafiltration peptide fractions

Protein hydrolysates with 20% and 30% degrees of hydrolysis (DH) were produced from alcalase hydrolysis of Pacific white shrimp shells. The study aimed to investigate the antioxidant and antihypertensive activities of these protein hydrolysates, focusing on peptide fractions of various molecular weights (MW) obtained through ultrafiltration. The 30% DH protein hydrolysate (SSPH) showed the highest antioxidant activities and was subjected to ultrafiltration to produce peptides of various molecular weights (MW) (F1:10–50, F2:5–10, F3:3–5, F4:1-3, and F5:<1 kDa). SSPH showed higher hydrophilic and non-essential amino acid content, among which alanine and aspartic acid were at higher levels. The obtained peptide fractions were analyzed for various antioxidant activities and inhibitory activities against angiotensin-converting enzyme and renin. F4 and F2 samples showed the highest DPPH (2.00 mM TE/g sample) and ABTS (60.68 mM TE/g sample) radical scavenging activities, respectively. Superoxide and hydrogen peroxide radical scavenging activity augmented with decreasing MW, aside from for F1, which showed higher activity than F2–F4 (p < 0.05). The highest ACE-inhibitory activity was found for the F2 fraction (44%–55%), and renin inhibitory activity increased with decreasing MW, in which F5 (12%–22%) was the most effective (p < 0.05). F5 showed 6 major peptides, among which KLVRGSKS and LPKKCLSARPG were the dominant sequences. Thus, this study suggests that shrimp shell protein isolate could be an alternative protein source for peptides with various antioxidant and antihypertensive activities, with potential applications in functional foods and nutraceuticals aimed at mitigating oxidative stress and hypertension.

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.

Association between TyG index and long-term prognosis of patients with ST-segment elevated myocardial infarction undergoing percutaneous coronary intervention: a retrospective cohort study

ObjectiveTo assess the association between the serum triglyceride-glucose product index (TyG index) and the risk for all-cause mortality in patients with ST-segment elevated myocardial infarction (STEMI).DesignRetrospective.Setting and participantsThis retrospective study...

Discarded CHO cells as a valuable source of bioactive peptides for sustainable biotechnological applications

Repurposing discarded cells stands as a groundbreaking paradigm shift in sustainable biotechnology, with profound implications across diverse industrial sectors. Our study proposes a transformative concept by harnessing histone proteins from discarded CHO cells to produce bioactive peptides. We systematically isolated and hydrolyzed histones using Trypsin and Neutrase enzymes, optimizing reaction conditions. Ultrafiltration yielded distinct peptide fractions (<3 kDa and 3–10 kDa), which we analyzed for DPP-IV inhibition, antioxidant potential, and other activities. Furthermore, LC-Q-TOF-MS analysis and in silico tools unveiled the structural composition of bioactive peptides within these fractions. Three peptide sequences with high bioactivity potential were identified: KLPFQR, VNRFLR, and LSSCAPVFL. Our findings demonstrated exceptional DPP-IV inhibition, potent antioxidant effects, and effective anti-lipid peroxidation activities, surpassing reference compounds. Hemolytic activity assessment indicated promising biocompatibility, enhancing therapeutic application prospects. Pioneering the strategic repurposing of discarded cells, this research addresses cost-efficiency in cell-based studies and promotes sustainable use of biological resources across sectors. This novel approach offers an efficient, eco-friendly method for bioactive molecule procurement and resource management, revolutionizing cell culture studies and biotechnological applications.

Alared: Solvatochromic and Fluorogenic Red Amino Acid for Ratiometric Live-Cell Imaging of Bioactive Peptides.

To fill the need for environmentally sensitive fluorescent unnatural amino acids able to operate in the red region of the spectrum, we have designed and synthesized Alared, a red solvatochromic and fluorogenic amino acid derived from the Nile Red chromophore. The new unnatural amino acid can be easily integrated into bioactive peptides using classical solid-phase peptide synthesis. The fluorescence quantum yield and the emission maximum of Alared-labeled peptides vary in a broad range depending on the peptide's environment, making Alared a powerful reporter of biomolecular interactions. Due to its red-shifted absorption and emission spectra, Alared-labeled peptides could be followed in living cells with minimal interference from cellular autofluorescence. Using ratiometric fluorescence microscopy, we were able to track the fate of the Alared-labeled peptide agonists of the apelin G protein-coupled receptor upon receptor activation and internalization. Due to its color-shifting environmentally sensitive emission, Alared allowed for distinguishing the fractions of peptides that are specifically bound to the receptor or unspecifically bound to different cellular membranes.

Decreased plasma ELABELA level as a novel screening indicator for heart failure: a cohort and observational study.

The predictive power of B-type natriuretic peptide (BNP) and left ventricular ejection fraction (LVEF) is limited by its low specificity in patients with heart failure (HF). Discovery of more novel biomarkers for HF better diagnosis is necessary and urgent. ELABELA, an early endogenous ligand for the G protein-coupled receptor APJ (Apelin peptide jejunum, Apelin receptor), exhibits cardioprotective actions. However, the relationship between plasma ELABELA and cardiac function in HF patients is unclear. To evaluate plasma ELABELA level and its diagnostic value in HF patients, a total of 335 patients with or without HF were recruited for our monocentric observational study. Plasma ELABELA and Apelin levels were detected by immunoassay in all patients. Spearman correlation analysis was used to analyze the correlation between plasma ELABELA or Apelin levels and study variables. The receiver operating characteristic curves were used to access the predictive power of plasma ELABELA or Apelin levels. Plasma ELABELA levels were lower, while plasma Apelin levels were higher in HF patients than in non-HF patients. Plasma ELABELA levels were gradually decreased with increasing New York Heart Association grade or decreasing LVEF. Plasma ELABELA levels were negatively correlated with BNP, left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left ventricular posterior wall thickness and positively correlated with LVEF in HF patients. In contrast, the correlation between plasma Apelin levels and these parameters is utterly opposite to ELABELA. The diagnostic value of ELABELA, Apelin, and LVEF for all HF patients was 0.835, 0.673, and 0.612; the sensitivity was 62.52, 66.20, and 32.97%; and the specificity was 95.92, 67.23, and 87.49%, respectively. All these parameters in HF patients with preserved ejection fraction were comparable to those in total HF patients. Overall, plasma ELABELA levels were significantly reduced and negatively correlated with cardiac function in HF patients. Decreased plasma ELABELA levels may function as a novel screening biomarker for HF. A combined assessment of BNP and ELABELA may be a good choice to increase the accuracy of the diagnosis of HF.

First report of antioxidant potential of peptide fraction derived from Colaconema formosanum (Rhodophyta) protein hydrolysates

Foods that contain natural antioxidants can improve people's health and performance and make them more resistant to environmental stressors like diseases, lousy living conditions, and heat stress. Marine algae are well known for their function as an antioxidant. Colaconema formosanum is a new rhodophyte discovered in Taiwan and its bioactive activities are rarely studied. This work aims to prepare the protein hydrolysate fraction with antioxidant properties in C. formosanum using single enzyme or complex enzyme hydrolysis. Afterward, a 3 kDa molecular weight cut-off (MWCO) was used for centrifugation, and then fractionation was carried out using Strong Cation Exchange (SCX) Chromatography. The quantification of antioxidant activity was performed using the DPPH test. The results showed that the thermolysin hydrolysate (IC50 1.48 ± 0.92 mg/mL) and the combination of trypsin-thermolysin hydrolysates (IC50 1.37 ± 0.84 mg/mL) had the highest antioxidant activity. The fractionation procedure with strong cation exchange (SCX) yielded fraction C from thermolysin hydrolysates, which exhibited the most significant antioxidant activity with an IC50 value of 0.47 ± 0.02 mg/mL. The fraction 4 derived from trypsin-thermolysin hydrolysates exhibited the most potent antioxidant activity (IC50: 0.34 ± 0.002 mg/mL). No previous reports have been made about the antioxidant properties of the hydrolysate fractions derived from C. formosanum proteins. Consequently, these findings could serve as a foundation for exploring peptides that have potential therapeutic sources for reducing oxidative stress.

Fractionation and identification of bioactive peptides from red macroalgae protein hydrolysates: In silico analysis and in vitro bioactivities

Recently, bioactive peptides derived from algae sources have gained significant recognition as vital functional ingredients in the development of health-enhancing foods and nutraceuticals. In this study, protein hydrolysates (SCPH and GSPH) derived from two red macroalgae (Sphaerococcus coronopifolius and Gelidium spinosum) were fractionated using semi-preparative-reversed phase high-performance liquid chromatography (RP-HPLC). Then, the peptides contained in the obtained fractions were identified by RP-HPLC coupled with tandem mass spectrometry (MS/MS). In silico analyzes of hydrophobicity, potential bioactivity using PeptideRanker, and toxicity of identified peptides were performed. Moreover, the prediction of Angiotensin-converting enzyme (ACE)- and Dipeptidyl-peptidase (DPP-IV)-inhibitory peptides using a quantitative structure-activity relationship (QSAR) was also carried out. Furthermore, in vitro evaluation of antioxidant and antibacterial activities, as well as ACE-, and DPP-IV-inhibitory properties was conducted for all peptide fractions. Our results showed that SCPH and GSPH fractions contain a large percentage of highly hydrophobic peptides with low molecular weight, and they exhibit no toxic effect. Among all identified peptides, 61 and 39 peptides, respectively from SCPH and GSPH fractions, presented a PeptideRanker score superior to 0.8. These peptide sequences exhibited a high proportion of potent predicted ACE- and DPP-IV-inhibitory peptides. Additionally, most of the peptide fractions exerted antioxidant, antibacterial, anti-ACE, and anti-DPP-IV inhibitory activities at different levels. Among them, F2 to F6 were the most active fractions. Overall, the results suggest that the bioactive peptide fractions separated from two red macroalgae protein hydrolysates could be considered as a beneficial ingredient for nutraceutical and functional food industries.

Acetaminophen used at therapeutic dosage causes significant changes in signaling pathways in mouse hearts

Acetaminophen (APAP) is a common over-the-counter medication that is used to treat pain and fever. It can be taken orally, topically, or intravenously and is considered a safe and effective drug when taken at therapeutic doses for a short amount of time. However, recent research suggests that APAP taken regularly can result in increased blood pressure, resulting in increased cardiovascular risk. Previous publications found that non-steroidal anti-inflammatory drugs (NSAIDs) resulted in increased Reactive Oxygen Species (ROS) in cardiomyocytes, resulting in cardiac dysfunction. Although APAP is not an NSAID, it is likely that APAP has similar effects. Our hypothesis is that regular usage of APAP increases ROS levels, leading to potential dysfunction in hearts and other organs. We treated five 6-month-old female mice with either water or acetaminophen dissolved in water for seven days. The concentration of acetaminophen that mice were given was 103 mg/kg/day, which is equivalent to a daily 500 mg dosage of acetaminophen in humans. The heart samples from these mice were homogenized in urea lysis buffer and then centrifuged to separate the supernatant from the pellet. After discarding the pellet, the proteins in the supernatant were discarded, and the pellet was treated with acetone overnight to allow the protein to precipitate. The supernatant was discarded, and the pellet was kept and denatured with tris(2-carboxyethyl) phosphine (TCEP) while incubating in a 55ºC dry bath, iodoacetamide was added to prevent disulfide bonds from forming, and acetone was added to the supernatant and left overnight to make proteins precipitate. After precipitation, the sample was centrifuged again to separate the supernatant from the pellet, and the pellet was saved while the supernatant was discarded. The pellet was resuspended and Tandem Mass Tags (TMT) label reagents were added to the samples, the samples quenched, and then combined and analyzed using mass spectroscopy (MS) after fractionating the samples using a Pierce High pH Reverse-Phase Peptide Fractionation kit (Thermofisher), then separated and eluted in liquid chromatography (LC) to determine any changes in the protein. LC/MS/MS data underwent a power analysis and Sequest-HT to compare samples to all mouse sequences. Target Decoy PSM was used to analyze and exclude decoy sequences from the samples, and Scaffold Q+ was used to quantify the peptides and proteins identified from the MS and LC data. Pathway analysis of the significant protein expression changes suggests antioxidant pathways, the ubiquitin-proteasome system, fatty acid oxidation, oxidative phosphorylation, and de novo purine synthesis and degradation. Proteasome assays were also conducted for the β5, β2, and β1 proteolytic subunits. There was a significant decrease in the β5 chymotrypsin-like activity in the hearts of APAP-treated mice compared to the control mice and no significant change in the β2 and β1 proteasome activity. Overall, these results show that mice treated with a therapeutic dosage of APAP regularly over the course of a week exhibited increased stress in the heart. NIEHS/Superfund Research Program (P42 ES004699). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Influence of Soy Protein Hydrolysates on Thermo-Mechanical Properties of Gluten-Free Flour and Muffin Quality

The influence of protease-assisted hydrolysis on the impact exerted by the soy protein isolate on the thermo-mechanical behavior and baking performance of the gluten-free composite flour, consisting of a mixture of rice and quinoa flours, was investigated. The mPAGE analysis revealed that soluble fractions of the hydrolysates, obtained with bromelain, Neutrase or trypsin, concentrated the peptides with a molecular weight lower than 20 kDa, whereas the insoluble ones retained higher molecular weight fragments. The influence of the separate and cumulative addition of the soluble and insoluble soy peptide fractions on the thermo-mechanical properties of dough was tested by means of a Mixolab device. Regardless of the enzyme used for hydrolysis, the addition of the soluble peptide fraction to the gluten-free composite flour resulted in delayed starch gelatinization, whereas the insoluble one caused a considerable increase in the dough consistency. The most important improvements in the dough behavior were observed when supplementing the gluten-free flour with 10% soy protein hydrolysates obtained with bromelain and trypsin. The gluten-free muffins enriched in soy protein hydrolysate exhibited important differences in terms of moisture, height and specific volume, compared to the control. Moreover, the ABTS- and DPPH-based methods indicated that protein hydrolysate addition caused a significant improvement in the antioxidant activity (by at least 38% and 23%, respectively) compared to the control. In conclusion, soy protein hydrolysate might be successfully used for increasing both the protein content and the antioxidant activity of the muffin samples.

Biological properties of LMW-peptide fractions from apricot kernel protein: Nutritional, antibacterial and ACE-inhibitory activities

In this study, angiotensin-converting enzyme (ACE) inhibitory, antioxidant and antibacterial activities, and nutritional quality of low molecular weights (LMWs) peptide fractions (PFs) from apricot-kernel (Prunus armeniaca cv. Tabarzeh) with PFs <3, 3–10, 10–30 and 30–100 kDa were investigated. The ratio of essential to total (E/T) amino acids (∼34.5 %) and PER value (1.8–1.9) indicated the high nutritional and digestibility of peptide fractions. Antioxidant indices were affected by enzymatic hydrolysis, molecular weight (Mw) and concentration of peptides. In general, the highest inhibition of DPPH− (89.2 %), ABTS+ (93.1 %), TEAC (2.52 mM), OH• (78.1 %), NO• (70.4 %), total antioxidant activity (2.01), reducing power (1.27), ACE inhibitory (75.1 %), chelation of Fe2+ (90.2 %) and Cu2+ (40.2 %) metal-ions were related to low Mw fractions (PF-3 and PF-10). The hydrolysates and primary protein showed enhanced antibacterial effects against Escherichia coli and Bacillus cereus with diameter of inhibition zones of 17 and 14 mm, respectively. Overall, apricot-kernel peptides can be considered as a nutrient source, natural antioxidant and preservative with ACE-inhibitory effect in dietary supplements and food formulations.