Molecular Mechanistic Insights into Dipeptidyl Peptidase-IV Inhibitory Peptides to Decipher the Structural Basis of Activity.

Dipeptidyl peptidase-IV (DPP-IV) inhibiting peptides have attracted increased attention because of their possible beneficial effects on glycemic homeostasis. However, the structural basis underpinning their activities has not been well understood. This study combined computational and in vitro investigations to explore the structural basis of DPP-IV inhibitory peptides. We first superimposed the Xaa-Pro-type peptide-like structures from several crystal structures of DPP-IV ligand-protein complexes to analyze the recognition interactions of DPP-IV to peptides. Thereafter, a small set of Xaa-Pro-type peptides was designed to explore the effect of key interactions on inhibitory activity. The intramolecular interaction of Xaa-Pro-type peptides at the first and third positions from the N-terminus was pivotal to their inhibitory activities. Residue interactions between DPP-IV and residues of the peptides at the fourth and fifth positions of the N-terminus contributed significantly to the inhibitory effect of Xaa-Pro-type tetrapeptides and pentapeptides. Based on the interaction descriptors, quantitative structure-activity relationship (QSAR) studies with the DPP-IV inhibitory peptides resulted in valid models with high R2 values (0.90 for tripeptides; 0.91 for tetrapeptides and pentapeptides) and Q2 values (0.33 for tripeptides; 0.68 for tetrapeptides and pentapeptides). Taken together, the structural information on DPP-IV and peptides in this study facilitated the development of novel DPP-IV inhibitory peptides.

Self-Assembled Food Peptides: Recent Advances and Perspectives in Food and Health Applications.

Self-assembling peptides are rapidly gaining attention as novel biomaterials for food and biomedical applications. Peptides self-assemble when triggered by physical or chemical factors due to their versatile physicochemical characteristics. Peptide self-assembly, when combined with the health-promoting bioactivity of peptides, can also result in a plethora of biofunctionalities of the biomaterials. This perspective highlights current developments in the use of food-derived self-assembling peptides as biomaterials, bioactive nutraceuticals, and potential dual functioning bioactive biomaterials. Also discussed are the challenges and opportunities in the use of self-assembling bioactive peptides in designing biocompatible, biostable, and bioavailable multipurpose biomaterials.

Microalgae Proteins as Sustainable Ingredients in Novel Foods: Recent Developments and Challenges.

Microalgae are receiving increased attention in the food sector as a sustainable ingredient due to their high protein content and nutritional value. They contain up to 70% proteins with the presence of all 20 essential amino acids, thus fulfilling human dietary requirements. Microalgae are considered sustainable and environmentally friendly compared to traditional protein sources as they require less land and a reduced amount of water for cultivation. Although microalgae's potential in nutritional quality and functional properties is well documented, no reviews have considered an in-depth analysis of the pros and cons of their addition to foods. The present work discusses recent findings on microalgae with respect to their protein content and nutritional quality, placing a special focus on formulated food products containing microalgae proteins. Several challenges are encountered in the production, processing, and commercialization of foods containing microalgae proteins. Solutions presented in recent studies highlight the future research and directions necessary to provide solutions for consumer acceptability of microalgae proteins and derived products.

Screening, separation and identification of metal-chelating peptides for nutritional, cosmetics and pharmaceutical applications.

Metal-chelating peptides, which form metal-peptide coordination complexes with various metal ions, can be used as biofunctional ingredients notably to enhance human health and prevent diseases. This review aims to discuss recent insights into food-derived metal-chelating peptides, the strategies set up for their discovery, their study, and identification. After understanding the overall properties of metal-chelating peptides, their production from food-derived protein sources and their potential applications will be discussed, particularly in nutritional, cosmetics and pharmaceutical fields. In addition, the review provides an overview of the last decades of progress in discovering food-derived metal-chelating peptides, addressing several screening, separation and identification methodologies. Furthermore, it emphasizes the methods used to assess peptide-metal interaction, allowing for better understanding of chemical and thermodynamic parameters associated with the formation of peptide-metal coordination complexes, as well as the specific amino acid residues that play important roles in the metal ion coordination.

Changes in Polar Lipid Composition in Balsam Fir during Seasonal Cold Acclimation and Relationship to Needle Abscission.

Needle abscission in balsam fir has been linked to both cold acclimation and changes in lipid composition. The overall objective of this research is to uncover lipid changes in balsam fir during cold acclimation and link those changes with postharvest abscission. Branches were collected monthly from September to December and were assessed for cold tolerance via membrane leakage and chlorophyll fluorescence changes at -5, -15, -25, -35, and -45 °C. Lipids were extracted and analyzed using mass spectrometry while postharvest needle abscission was determined gravimetrically. Cold tolerance and needle retention each significantly (p < 0.001) improved throughout autumn in balsam fir. There were concurrent increases in DGDG, PC, PG, PE, and PA throughout autumn as well as a decrease in MGDG. Those same lipids were strongly related to cold tolerance, though MGDG had the strongest relationship (R2 = 55.0% and 42.7% from membrane injury and chlorophyll fluorescence, respectively). There was a similar, albeit weaker, relationship between MGDG:DGDG and needle retention (R2 = 24.3%). Generally, a decrease in MGDG:DGDG ratio resulted in better cold tolerance and higher needle retention in balsam fir, possibly due to increased membrane stability. This study confirms the degree of cold acclimation in Nova Scotian balsam fir and presents practical significance to industry by identifying the timing of peak needle retention. It is suggested that MGDG:DGDG might be a beneficial tool for screening balsam fir genotypes with higher needle retention characteristics.

Quantitative Structure-Activity Relationship Modeling of Pea Protein-Derived Acetylcholinesterase and Butyrylcholinesterase Inhibitory Peptides.

The aim of this work was to determine the structural requirements for peptides that inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities. The data set used consisted of 19 oligopeptides that had been identified through mass spectrometry analysis of enzymatic digests of yellow field pea protein. The structure-function relationship was analyzed by partial least squares regression using the 5z scores. A nine-component model was created from 16 peptides for AChE inhibitory peptides (Q2 = 67.2% and R2 = 0.9974), while three data sets were prepared for BuChE inhibitory peptides to improve the quality of the models (Q2 = 26.7-46.4% and R2 = 0.9577-0.9958). The most active peptides from the PLS models have threonine, leucine, alanine, and valine at the N terminal, asparagine, histidine, proline, and arginine at the second position, with aspartic acid and serine at the third, and arginine at the C terminal.

Big Things, Small Packages: An Update on Microalgae as Sustainable Sources of Nutraceutical Peptides for Promoting Cardiovascular Health.

In 2017, a review of microalgae protein-derived bioactive peptides relevant in cardiovascular disease (CVD) management was published. Given the rapid evolution of the field, an update is needed to illumininate recent developments and proffer future suggestions. In this review, the scientific literature (2018-2022) is mined for that purpose and the relevant properties of the identified peptides related to CVD are discussed. The challenges and prospects for microalgae peptides are similarly discussed. Since 2018, several publications have independently confirmed the potential to produce microalgae protein-derived nutraceutical peptides. Peptides that reduce hypertension (by inhibiting angiotensin converting enzyme and endothelial nitric oxide synthase), modulate dyslipidemia and have antioxidant and anti-inflammatory properties have been reported, and characterized. Taken together, future research and development investments in nutraceutical peptides from microalgae proteins need to focus on the challenges of large-scale biomass production, improvement in techniques for protein extraction, peptide release and processing, and the need for clinical trials to validate the claimed health benefits as well as formulation of various consumer products with the novel bioactive ingredients.

Relation of amino acid composition, hydrophobicity, and molecular weight with antidiabetic, antihypertensive, and antioxidant properties of mixtures of corn gluten and soy protein hydrolysates.

New mixed Alcalase-hydrolysates were developed using corn gluten meal (CP) and soy protein (SP) hydrolysates, namely CPH, SPH, SPH30:CPH70, SPH70:CPH30, and SPH50:CPH50. Amino acid profile, surface hydrophobicity (H 0), molecular weight (MW) distribution, antioxidant activity, angiotensin-converting enzyme (ACE), α-amylase, and α-glucosidase inhibitory activities, and functional characteristics of hydrolysates were determined. Hydrolysis changed the amount of hydrophilic and hydrophobic amino acid composition and significantly increased the H 0 values of hydrolysates, especially for CPH. The DPPH radical scavenging activity (RSA) was higher for CPH, SPH30:CPH70, and SPH50:CPH50 than SPH and SPH70:CPH30. Moreover, SPH, SPH70:CPH30, and SPH50:CPH50 showed lower MW than CPH, and this correlated with the higher hydrophilicity, and ABTS and hydroxyl RSA values obtained for SPH and the mixed hydrolysates with predominantly SPH. SPH70:CPH30 exhibited higher ACE, α-glucosidase, and α-amylase inhibitory activities among all samples due to its specific peptides with high capacity to interact with amino acid residues located at the enzyme active site and also low binding energy. At 15% degree of hydrolysis, both SPH and CPH showed enhanced solubility at pH 4.0, 7.0 and 9.0, emulsifying activity, and foaming capacity. Taken together, SPH70:CPH30 displayed strong antioxidant, antihypertensive, and antidiabetic attributes, emulsifying activity and stability indexes, and foaming capacity and foaming stability, making it a promising multifunctional ingredient for the development of functional food products.

Flavour encapsulation: A comparative analysis of relevant techniques, physiochemical characterisation, stability, and food applications.

Flavour is an important component that impacts the quality and acceptability of new functional foods. However, most flavour substances are low molecular mass volatile compounds, and direct handling and control during processing and storage are made difficult due to susceptibility to evaporation, and poor stability in the presence of air, light, moisture and heat. Encapsulation in the form of micro and nano technology has been used to address this challenge, thereby promoting easier handling during processing and storage. Improved stability is achieved by trapping the active or core flavour substances in matrices that are referred to as wall or carrier materials. The latter serve as physical barriers that protect the flavour substances, and the interactions between carrier materials and flavour substances has been the focus of many studies. Moreover, recent evidence also suggests that enhanced bioavailability of flavour substances and their targeted delivery can be achieved by nanoencapsulation compared to microencapsulation due to smaller particle or droplet sizes. The objective of this paper is to review several relevant aspects of physical-mechanical and physicochemical techniques employed to stabilize flavour substances by encapsulation. A comparative analysis of the physiochemical characterization of encapsulates (particle size, surface morphology and rheology) and the main factors that impact the stability of encapsulated flavour substances will also be presented. Food applications as well as opportunities for future research are also highlighted.

Molecular Interaction of Pea Glutelin and Lipophilic Bioactive Compounds: Structure-Binding Relationship and Nano-/Microcomplexation.

This study investigated the impact of ionic strength and lipophilicity of bioactive compounds on their interaction with the alkaline soluble pea glutelin fraction (ASF) using the fluorescence quenching technique. A Stern-Volmer quenching constant, KD, of 8.9 ± 0.10, 5.3 ± 0.06, 4.0 ± 0.01, 1.1 ± 0.00, 0.9 ± 0.02, and 0.1 ± 0.00 (×104 M-1) was observed for curcumin-ASF (CuASF), astaxanthin-ASF (AsASF), cholecalciferol-ASF (ChASF), ß-carotene-ASF (ßCaASF), coenzyme Q10-ASF (Q10ASF), and ß-sitosterol-ASF (ßSiASF) complexes, respectively. An increase in ionic strength did not significantly change KD, the effective quenching constant K, and the bimolecular quenching rate constant KQ. However, it changed the mode of interaction of the ASF with cholecalciferol, ß-carotene, coenzyme Q10, and ß-sitosterol from static to static-dynamic quenching. Transmission electron microscopy showed that the morphology formed with protein (spherical nanocomplexes, microaggregates, or fiber-like particles) differed among the compounds. The favorable binding of CuASF, AsASF, ChASF, and ßCaASF complexes provides stable matrices for formulating protein-based delivery systems for lipophilic nutraceuticals.

In Silico Exploration of Metabolically Active Peptides as Potential Therapeutic Agents against Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is regarded as a fatal neurodegenerative disease that is featured by progressive damage of the upper and lower motor neurons. To date, over 45 genes have been found to be connected with ALS pathology. The aim of this work was to computationally identify unique sets of protein hydrolysate peptides that could serve as therapeutic agents against ALS. Computational methods which include target prediction, protein-protein interaction, and peptide-protein molecular docking were used. The results showed that the network of critical ALS-associated genes consists of ATG16L2, SCFD1, VAC15, VEGFA, KEAP1, KIF5A, FIG4, TUBA4A, SIGMAR1, SETX, ANXA11, HNRNPL, NEK1, C9orf72, VCP, RPSA, ATP5B, and SOD1 together with predicted kinases such as AKT1, CDK4, DNAPK, MAPK14, and ERK2 in addition to transcription factors such as MYC, RELA, ZMIZ1, EGR1, TRIM28, and FOXA2. The identified molecular targets of the peptides that support multi-metabolic components in ALS pathogenesis include cyclooxygenase-2, angiotensin I-converting enzyme, dipeptidyl peptidase IV, X-linked inhibitor of apoptosis protein 3, and endothelin receptor ET-A. Overall, the results showed that AGL, APL, AVK, IIW, PVI, and VAY peptides are promising candidates for further study. Future work would be needed to validate the therapeutic properties of these hydrolysate peptides by in vitro and in vivo approaches.

In vitro inhibition of acetylcholinesterase activity by yellow field pea (Pisum sativum) protein-derived peptides as revealed by kinetics and molecular docking.

Compounds with structural similarities to the neurotransmitter (acetylcholine) are mostly used to inhibit the activity of acetylcholinesterase (AChE) in Alzheimer's disease (AD) therapy. However, the existing drugs only alleviate symptoms of moderate to mild conditions and come with side effects; hence, the search is still on for potent and safer options. In this study, High performance liquid chromatography (HPLC) fractionations of AChE-inhibitory pea protein hydrolysates obtained from alcalase, flavourzyme and pepsin digestions were carried out followed by sequence identification of the most active fractions using mass spectrometry. Subsequently, 20 novel peptide sequences identified from the active fractions were synthesized and five peptides, QSQS, LQHNA, SQSRS, ETRSQ, PQDER (IC50 = 1.53 - 1.61 µg/mL) were selected and analyzed for ability to change AChE protein conformation (fluorescence emission and circular dichroism), kinetics of enzyme inhibition, and enzyme-ligand binding configurations using molecular docking. The kinetics studies revealed different inhibition modes by the peptides with relatively low (<0.02 mM and <0.1 mM) inhibition constant and Michaelis constant, respectively, while maximum velocity was reduced. Conformational changes were confirmed by losses in fluorescence intensity and reduced α-helix content of AChE after interactions with different peptides. Molecular docking revealed binding of the peptides to both the catalytic anionic site and the peripheral anionic site. The five analyzed peptides all contained glutamine (Q) but sequences with Q in the penultimate N-terminal position (LQHNA, SQSRS, and PQDER) had stronger binding affinity. Results from the different analysis in this study confirm that the peptides obtained from enzymatic digestion of pea protein possess the potential to be used as novel AChE-inhibitory agents in AD management.

Transepithelial transport and cellular mechanisms of food-derived antioxidant peptides.

Considering the involvement of oxidative stress in the etiology of many non-communicable diseases, food-derived antioxidant peptides (FDAPs) are strong candidates for nutraceutical development for disease prevention and management. This paper reviews current evidence on the transepithelial transport and cellular mechanisms of antioxidant activities of FDAPs. Several FDAPs have multiple health benefits such as anti-inflammatory and anti-photoaging activities, in addition to antioxidant properties through which they protect cellular components from oxidative damage. Some FDAPs have been shown to permeate the intestinal epithelium, which could facilitate their bioavailability and physiological bioactivities. Molecular mechanisms of FDAPs include suppression of oxidative stress as evidenced by reduction in intracellular reactive oxygen species production, lipid peroxidation and apoptotic protein activation as well as increase in antioxidant defense mechanisms (enzymatic and non-enzymatic). Since many FDAPs have demonstrated promising antioxidant activity, future investigation should focus on further elucidation of molecular mechanisms and human studies to explore their practical application for the prevention and management of oxidative stress-related diseases.

Self-assembly and Hydrogelation Properties of Peptides Derived from Peptic Cleavage of Aggregation-prone Regions of Ovalbumin.

Egg white protein hydrolysate generated with pepsin was investigated for the presence of peptides with self-assembly and hydrogelation properties. Incubation of the hydrolysates for 16 h resulted in aggregates with significantly (p < 0.05) lower free amino nitrogen and sulfhydryl contents, and higher particle diameter and surface hydrophobicity compared to the hydrolysates. LC-MS/MS analysis of the aggregates resulted in identification of 429 ovalbumin-derived peptides, among which the top-six aggregation-prone peptides IFYCPIAIM, NIFYCPIAIM, VLVNAIVFKGL, YCPIAIMSA, MMYQIGLF, and VYSFSLASRL were predicted using AGGRESCAN by analysis of the aggregation "Hot Spots". NIFYCPIAIM had the highest thioflavin T fluorescence intensity, particle diameter (5611.3 nm), and polydispersity index (1.0) after 24 h, suggesting the formation of ß-sheet structures with heterogeneous particle size distribution. Transmission electron microscopy of MMYQIGLF, and VYSFSLASRL demonstrated the most favorable peptide self-assembly, based on the formation of densely packed, intertwined fibrils. Rheological studies confirmed the viscoelastic and mechanical properties of the hydrogels, with IFYCPIAIM, NIFYCPIAIM, VLVNAIVFKGL, and VYSFSLASRL forming elastic solid hydrogels (tan δ < 1), while YCPIAIMSA and MMYQIGLF formed viscous liquid-like hydrogels (tan δ > 1). The results provide valuable insight into the influence of peptide sequence on hydrogelation and self-assembly progression, and prospects of food peptides in biomaterial applications.

Preparation, pungency and bioactivity of gingerols from ginger (Zingiber officinale Roscoe): a review.

Ginger has been widely used for different purposes, such as condiment, functional food, drugs, and cosmetics. Gingerols, the main pungent component in ginger, possess a variety of bioactivities. To fully understand the significance of gingerols in the food and pharmaceutical industry, this paper first recaps the composition and physiochemical properties of gingerols, and the major extraction and synthesis methods. Furthermore, the pungency and bioactivity of gingerols are reviewed. In addition, the food application of gingerols and future perspectives are discussed. Gingerols, characterized by a 3-methoxy-4-hydroxyphenyl moiety, are divided into gingerols, shogaols, paradols, zingerone, gingerdiones and gingerdiols. At present, gingerols are extracted by conventional, innovative, and integrated extraction methods, and synthesized by chemical, biological and in vitro cell synthesis methods. Gingerols can activate transient receptor potential vanilloid type 1 (TRPV1) and induce signal transduction, thereby exhibiting its pungent properties and bioactivity. By targeted mediation of various cell signaling pathways, gingerols display potential anticancer, antibacterial, blood glucose regulatory, hepato- and renal-protective, gastrointestinal regulatory, nerve regulatory, and cardiovascular protective effects. This review contributes to the application of gingerols as functional ingredients in the food and pharmaceutical industry.

Osteo-modulatory dietary proteins and peptides: A concise review.

The integrity of the bone is dependent on the strict balance between osteoclastogenesis and osteoblastogenesis, and any imbalance results in bone diseases. Dietary proteins (DP) have been shown to promote osteogenesis while inhibiting bone resorption in cultured osteoblasts, and in animal models of bone diseases such as ovariectomy, 1α,25-dihydroxy-vitamin D3 (VD3), and prostaglandin E2 (PGE2)-induced bone resorption. Hydrolysis of some of these DPs with osteo-modulatory properties has been shown to generate hydrolysates with bioactive peptides that exhibit higher osteo-modulatory properties in comparison to intact (parent) proteins. The higher bioactivity of the isolated peptides and protein hydrolysates compared to intact proteins indicates that the osteo-modulatory properties are dependent on the degree of exposure of the functional groups of amino acid residues involved in target interaction. This review provides an overview of the preparation of DP and select peptides with osteo-modulatory properties, and summarizes the potential underlying mechanisms of action through which the bioactive peptides help maintain bone health. PRACTICAL APPLICATIONS: Bone diseases such as osteoporosis (OP), osteoarthritis (OA), bone cancer (BC), and others have negative impacts on the quality of life, especially in older women after menopause. Current drugs used in treating many bone diseases such as bisphosphonates, anabolic steroids, and selective estrogen receptor modulators have been limited by worrisome adverse effects such as organ toxicity, increased risk of cancer, and cardiovascular abnormalities, and gastrointestinal discomfort. There is growing scientific evidence that certain multifunctional dietary proteins and bioactive peptides may positively modulate bone health by modifying risk factors for bone diseases including inflammation, oxidative stress, hyperlipidemia, and hyperglycemia.

Legume Seed Protein Digestibility as Influenced by Traditional and Emerging Physical Processing Technologies.

The increased consumption of legume seeds as a strategy for enhancing food security, reducing malnutrition, and improving health outcomes on a global scale remains an ongoing subject of profound research interest. Legume seed proteins are rich in their dietary protein contents. However, coexisting with these proteins in the seed matrix are other components that inhibit protein digestibility. Thus, improving access to legume proteins often depends on the neutralisation of these inhibitors, which are collectively described as antinutrients or antinutritional factors. The determination of protein quality, which typically involves evaluating protein digestibility and essential amino acid content, is assessed using various methods, such as in vitro simulated gastrointestinal digestibility, protein digestibility-corrected amino acid score (IV-PDCAAS), and digestible indispensable amino acid score (DIAAS). Since most edible legumes are mainly available in their processed forms, an interrogation of these processing methods, which could be traditional (e.g., cooking, milling, extrusion, germination, and fermentation) or based on emerging technologies (e.g., high-pressure processing (HPP), ultrasound, irradiation, pulsed electric field (PEF), and microwave), is not only critical but also necessary given the capacity of processing methods to influence protein digestibility. Therefore, this timely and important review discusses how each of these processing methods affects legume seed digestibility, examines the potential for improvements, highlights the challenges posed by antinutritional factors, and suggests areas of focus for future research.

TNKPVI, a Putative Bioaccessible Pharmacophore of Anti-Inflammatory Potato Patatin-Derived Decapeptide DIKTNKPVIF.

Potato protein-derived decapeptide DIKTNKPVIF exerted anti-inflammatory activity in animal models when delivered via intragastric gavage and intraperitoneal injection. However, DIKTNKPVIF is susceptible to hydrolysis in the digestive tract, which will decrease its bioaccessibility and possibly bioactivity. In this study, the anti-inflammatory activity of fragments generated from in silico gastrointestinal enzymatic hydrolysis of DIKTNKPVIF was investigated using the human monocytic (THP-1) cell line. The simulated digestion by pepsin and trypsin released four fragments, DIKTNKPVI, TNKPVIF, DIK and TNKPVI. The peptides lacked the cleavage sites of chymotrypsin. All five peptides were predicted to be non-toxic, which was validated using cytotoxicity assay at 0.25-1 mM peptide concentration. However, the peptides were predicted to possess poor pharmacokinetic profiles, including low passive gastrointestinal absorption and blood-brain barrier permeability. TNKPVIF, DIK and TNKPVI significantly reduced the amount of pro-inflammatory interleukin (IL)-6, IL-8 and tumor necrosis factor in lipopolysaccharide-activated THP-1 cells. Notably, the anti-inflammatory activity of fragment TNKPVI was comparable to that of the parent decapeptide while peptide fragment DIKTNKPVI had no apparent effect on the pro-inflammatory cytokines. This highlights the important role of the C-terminal phenylalanine residue of the parent peptide in the bioactivity. Furthermore, given its activity and the absence of cleavage sites of major digestive proteases, TNKPVI could be the biostable and bioaccessible pharmacophore of potato patatin-derived anti-inflammatory decapeptide DIKTNKPVIF.

Bioinformatics analysis of adhesin-binding potential and ADME/Tox profile of anti-Helicobacter pylori peptides derived from wheat germ proteins.

Anti-adhesive activity of wheat germ-derived peptides, which is considered as one of the promising strategies for preventing Helicobacter pylori infection, was investigated. The underlying mechanism of anti-adhesive action was due to peptides acting as receptor analogues and binding to H. pylori adhesin proteins. However, there is lack of information on the nature and strength of this molecular interaction as well as the participating species and drug-likeness of the food-derived bioactive peptides. In this study, the biostability and ADME/Tox (absorption, distribution, metabolism, excretion and toxicity) profile of the anti-adhesive peptides were analyzed using bioinformatic tools, and their binding potential to H. pylori's adhesins estimated by molecular docking. Binding is facilitated by mostly hydrogen bonding and hydrophobic interaction occurring in the active site of the adhesin proteins with affinities ranging from -6.0 to -7.4 and -6.0 to -7.8 kcal/mol for BabA and SabA, respectively. The results indicate highly possible binding capabilities of the peptides to adhesin proteins. Out of 16 peptides studied, 14 bound in the vicinity of the active site of BabA and SabA whereas two different peptides demonstrated allosteric binding. The most hydrophobic peptide, P210 showed strong binding affinity for both BabA and SabA and, therefore, predicted to be the most promising peptide for further development in the prevention, management and treatment of H. pylori infection. The selected peptides were shown to be non-toxic, and to have high potential of localized effect of interfering with bacterial adherence. This work provides insights into the anti-adhesive mechanism of peptides and new evidence demonstrating bioactive peptides as promising nutraceutical candidates for preventing H. pylori infection.

Lentil Protein and Tannic Acid Interaction Limits in Vitro Peptic Hydrolysis and Alters Peptidomic Profiles of the Proteins.

In this study, the nature of lentil protein-tannic acid (LPTA) interaction and its effect on in vitro pepsin digestion were investigated. LPTA mixtures containing 1% w/v LP and 0.001-0.5% TA were prepared and characterized in terms of particle size, thermal properties, and secondary and tertiary structures. A 20-fold increase in particle size was observed in LPTA0.5% compared to LP control (without TA), indicating aggregation. Static quenching of tryptophan residues within the protein hydrophobic folds was observed. Increasing TA levels also enhanced protein thermal stability. Over 50% reduction in free amino groups of LPTA 0.5%, relative to LP, was observed after pepsin digestion. Cleavage specificity of pepsin and peptidomic profile of LP were modified by the presence of TA in LPTA 0.5%. This study showed that 0.5% w/v TA induced protein aggregation and reduced LP digestibility by hindering the accessibility of pepsin to the protein network, thus modifying the profile of released peptides.