Promising Peptide Research Articles

Design of Three Residues Peptides against SARS-CoV-2 Infection.

The continuous and rapid spread of the COVID-19 pandemic has emphasized the need to seek new therapeutic and prophylactic treatments. Peptide inhibitors are a valid alternative approach for the treatment of emerging viral infections, mainly due to their low toxicity and high efficiency. Recently, two small nucleotide signatures were identified in the genome of some members of the Coronaviridae family and many other human pathogens. In this study, we investigated whether the corresponding amino acid sequences of such nucleotide sequences could have effects on the viral infection of two representative human coronaviruses: HCoV-OC43 and SARS-CoV-2. Our results showed that the synthetic peptides analyzed inhibit the infection of both coronaviruses in a dose-dependent manner by binding the RBD of the Spike protein, as suggested by molecular docking and validated by biochemical studies. The peptides tested do not provide toxicity on cultured cells or human erythrocytes and are resistant to human serum proteases, indicating that they may be very promising antiviral peptides.

P070 Antimicrobial peptides from the Coleoptera family Scarabaeidae against Candida and Cryptococcus pathogenic yeasts.

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMObjectivesHost defense peptides (HDP) are produced by a diversity of beetles. The aims of this work were (1) to find new promising peptides from the Coleoptera family Scarabaeidae with potential biomedical applications, (2) to modify physicochemical and structural characteristics of one of the most promissory peptides in order to improve its antimicrobial properties, and (3) to evaluate the in vitro activity of the HDPs against reference strains of pathogenic Candida and Cryptococcus yeasts.Materials and MethodsFrom the Scarabaeidae family transcriptome, 14 promising HDPs were identified. Subsequently, we designed 19 new sequences from Act8 peptide modifying the net charge, hydrophobic angle, and the general composition of amino acids, among other properties, in order to improve the HDPs antifungal activity. The in vitro antifungal susceptibility of the 33 HDPs against C. albicans SC5314, C. krusei, ATCC 6558, C. parapsilosis ATCC 22019, C. glabrata ATCC 2001, C. tropicalis ATCC 750, C. neoformans H99, and C. gattii H0058-I-2029 isolates were evaluated by broth microdilution, with a concentration ranging from 0.19 to 50 μg/ml.ResultsAll 14 peptides identified showed in vitro activity against C. krusei, C. parapsilosis, and C. glabrata. One peptide showed in vitro activity against C. albicans, 6 against C. tropicalis, 11 against C. neoformans and 13 against C. gattii. As well the 19 modified peptides showed in vitro activity against C. krusei, C. parapsilosis, C. tropicalis, C. neoformans, and C. gattii. A total of 15 modified peptides showed in vitro activity against C. albicans, and 3 against C. glabrata. MIC ranges per species and per peptide are shown in Table 1.ConclusionsThe HDPs herein analyzed showed a significant in vitro antifungal activity against six Candida and two Cryptococcus pathogenic species. Our findings encourage further work with in vivo experimental models in order to better understand the action mechanisms of these antimicrobial peptides. HDPs from different species are becoming a promising therapeutic alternative in the control of fungal infections.

Electrospun fibers loaded with antimicrobial peptides for treatment of wound infections

The widespread resistance of clinically relevant bacteria against established antibiotics emphasizes the urgent need for novel therapeutics. In this context, wound infections constitute a specific challenge, as most systemically applied antibiotics are insufficiently available at the site of infection. Therefore, the local treatment of infected wounds poses a particular challenge regarding the appropriate release kinetics of actives and their residence time in the wound bed. Consequently, design and development of novel, drug-loaded wound dressings constitute a major research focus for the effective treatment of wound infections. In this study, we employed electrospinning to design drug-loaded wound dressings, incorporating the therapeutically promising antimicrobial peptide tyrothricin. By parallel electrospinning, we combined different ratios of water-soluble polyvinylpyrrolidone and water-insoluble methacrylate copolymer (EudragitE), in order to take advantage of their specific mechanical stability and dissolution properties. We fabricated fiber mats constituting mechanically stable wound dressings with a controlled drug release profile, combining an initial burst release above the minimal inhibitory concentration of known wound pathogens and a subsequent prolonged antimicrobial effect of the active ingredient. Antimicrobial activity against Staphylococcusaureus and Staphylococcusepidermidis was successfully proven, thereby introducing our tyrothricin-loaded fiber mats as a promising prospective therapy against typical wound-associated pathogens.

Synthesis and Evaluation of Two Long-Acting SSTR2 Antagonists for Radionuclide Therapy of Neuroendocrine Tumors.

Somatostatin receptor subtype 2 (SSTR2) has become an essential target for radionuclide therapy of neuroendocrine tumors (NETs). JR11 was introduced as a promising antagonist peptide to target SSTR2. However, due to its rapid blood clearance, a better pharmacokinetic profile is necessary for more effective treatment. Therefore, two JR11 analogs (8a and 8b), each carrying an albumin binding domain, were designed to prolong the blood residence time of JR11. Both compounds were labeled with lutetium-177 and evaluated via in vitro assays, followed by in vivo SPECT/CT imaging and ex vivo biodistribution studies. [177Lu]Lu-8a and [177Lu]Lu-8b were obtained with high radiochemical purity (>97%) and demonstrated excellent stability in PBS and mouse serum (>95%). [177Lu]Lu-8a showed better affinity towards human albumin compared to [177Lu]Lu-8b. Further, 8a and 8b exhibited binding affinities 30- and 48-fold lower, respectively, than that of the parent peptide JR11, along with high cell uptake and low internalization rate. SPECT/CT imaging verified high tumor accumulation for [177Lu]Lu-8a and [177Lu]Lu-JR11 at 4, 24, 48, and 72 h post-injection, but no tumor uptake was observed for [177Lu]Lu-8b. Ex vivo biodistribution studies revealed high and increasing tumor uptake for [177Lu]Lu-8a. However, its extended blood circulation led to an unfavorable biodistribution profile for radionuclide therapy.

Symposium 1-1 - Immunocontraceptive vaccine development using zona pellucida (ZP)

The zona pellucida (ZP) is an extracellular matrix surrounding ovarian oocytes, ovulated eggs and preimplantation embryos. Its constituent glycoproteins are expressed in a tissue-specific manner. Since the 1970s, ZP had been assumed to be a promising candidate for immunocontraceptive vaccines, because anti-ZP antibody blocked fertilization by prevention of sperm binding to ZP in vitro. Biochemical and immunological studies revealed that ZP is composed of glycoproteins and possesses strong antigenicity. It was thus considered that ZP could surely satisfy the requirements for effective contraceptive vaccines. Contraceptive vaccines for human use should be highly effective and reversible as well as safe. However, early animal experiments showed that infertility by ZP immunization resulted from ovarian impairment. Use of immunocontraceptive vaccines with naturally occurring ZP protein has thus been limited to wildlife population control. Application of recombinant ZP proteins was expected to provide safe and irreversible vaccines but ovarian pathology could not be avoided. As a next stage, contraceptive vaccine development continued through DNA engineering, whereby the antigens were not necessarily based on native amino acid sequences of ZP. Artificial DNA constructs coding multiple promising peptides were also prepared with GnRH and promiscuous T-cell epitopes. However, their efficacy was insufficient. Recently, single chain fragment for variable regions (scFv) has been proposed as a future strategy. The scFv is expected to bind directly to ZP in the inoculated animals by skipping the antibody production process. In conclusion, intensive studies and advances in technology have not achieved ideal targets for ZP-based immunocontraceptive vaccines at this moment. We are anticipating future scientific progress.

The antimicrobial peptide DGL13K is active against drug-resistant gram-negative bacteria and sub-inhibitory concentrations stimulate bacterial growth without causing resistance.

Antimicrobial peptides may be alternatives to traditional antibiotics with reduced bacterial resistance. The antimicrobial peptide GL13K was derived from the salivary protein BPIFA2. This study determined the relative activity of the L-and D-enantiomers of GL13K to wild-type and drug-resistant strains of three gram-negative species and against Pseudomonas aeruginosa biofilms. DGL13K displayed in vitro activity against extended-spectrum beta-lactamase (ESBL)-producing and Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (MICs 16–32 μg/ml), MDR and XDR P. aeruginosa, and XDR Acinetobacter baumannii carrying metallo-beta-lactamases (MICs 8–32 μg/ml). P. aeruginosa showed low inherent resistance to DGL13K and the increased metabolic activity and growth caused by sub-MIC concentrations of GL13K peptides did not result in acquired bacterial resistance. Daily treatment for approximately two weeks did not increase the MIC of DGL13K or cause cross-resistance between LGL13K and DGL13K. These data suggest that DGL13K is a promising antimicrobial peptide candidate for further development.

Lunasin as a Promising Plant-Derived Peptide for Cancer Therapy.

Cancer has become one of the main public health problems worldwide, demanding the development of new therapeutic agents that can help reduce mortality. Lunasin is a soybean peptide that has emerged as an attractive option because its preventive and therapeutic actions against cancer. In this review, we evaluated available research on lunasin’s structure and mechanism of action, which should be useful for the development of lunasin-based therapeutic products. We described data on its primary, secondary, tertiary, and possible quaternary structure, susceptibility to post-translational modifications, and structural stability. These characteristics are important for understanding drug activity and characterizing lunasin products. We also provided an overview of research on lunasin pharmacokinetics and safety. Studies examining lunasin’s mechanisms of action against cancer were reviewed, highlighting reported activities, and known molecular partners. Finally, we briefly discussed commercially available lunasin products and potential combination therapeutics.

A new synthetic protegrin as a promising peptide with antibacterial activity against MDR Gram-negative pathogens.

Protegrins are a family of natural peptides from the innate immune system of vertebrates, with broad-spectrum antimicrobial activity. However, the toxicity and haemolysis of protegrin-1 (PG-1) at low concentrations renders it useless for therapeutic application. We rationally designed PLP-3, a novel synthetic PG-1-like peptide, comprising key activity features of protegrins in a constrained bicyclic structure. Our main objective was to investigate PLP-3's activity against MDR strains of Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae and to analyse its haemolysis and cytotoxicity. Peptide synthesis was performed via solid phase and intramolecular ligation in solution, and the correct folding of the peptide was verified by circular dichroism. Antimicrobial activity was performed through broth microdilution. The test panel contained 45 bacterial strains belonging to A. baumannii, P. aeruginosa and K. pneumoniae (15 strains per species) comprising colistin-resistant and MDR strains. Cytotoxicity was assessed by XTT cell viability assays using HeLa and A549 cells and haemolysis of human erythrocytes. PLP-3 was successfully synthesized, and its antiparallel β-sheet conformation was confirmed. Antimicrobial activity screening showed MIC90 values of 2 mg/L for A. baumannii, 16 mg/L for K. pneumoniae and 8 mg/L for P. aeruginosa. The haemolysis IC50 value was 48.53 mg/L. Cytotoxicity against human HeLa and A549 cells showed values of ca. 200 mg/L in both cell lines resulting in a 100-fold selectivity window for bacterial over human cells. PLP-3 has potent antimicrobial activity, especially against A. baumannii, while maintaining low haemolysis and toxicity against human cell lines at antimicrobial concentrations. These characteristics make PLP-3 a promising peptide with an interesting therapeutic window.

Isolation and characterization of novel peptides from fermented products of Lactobacillus for ulcerative colitis prevention and treatment

Ulcerative colitis (UC) is an incurable and highly complex digestive disease affecting millions of people worldwide. Compared to the current therapeutic drugs, bioactive peptides are more promising and safe substances as functional foods or drugs for the prevention and treatment of UC. The alcohol-soluble components from fermentation broth by fresh wheat germ and apple (AC-WGAF) were found to be effective in UC prevention in dextran sulfate sodium-induced mice in vivo. Herein, 4 novel peptides are identified from AC-WGAF by membrane ultrafiltration, recycling preparative high-performance liquid chromatography, and matrix-assisted laser desorption–ionization time-of-flight/time-of-flight mass spectrometry, possessing anti-colitis activity via using an in vitro model. One of those peptides named T24 (PVLGPVRGPFPLL) exhibited the most remarkable anti-colitis activity by preventing tight junction protein loss, maintaining epithelial barrier integrity, and promoting cell proliferation during in vitro and in vivo studies by regulating mitogen-activated protein kinase signaling pathways. Thus, T24 is a promising peptide as a functional food or novel drug for UC prevention and treatment.

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.

Cell-Penetrating Peptide TAT-HuR-HNS3 Suppresses Proinflammatory Gene Expression via Competitively Blocking Interaction of HuR with Its Partners.

Proinflammatory cytokines/chemokines are commonly regulated by RNA-binding proteins at posttranscriptional levels. Human Ag R (HuR)/embryonic lethal abnormal vision-like 1 (ELAVL1) is one of the well-characterized RNA-binding proteins that increases the stability of short-lived mRNAs, which encode proinflammatory mediators. HuR employs its nucleocytoplasmic shuttling sequence (HNS) domain, interacting with poly(ADP-ribose) polymerase 1 (PARP1), which accounts for the enhanced poly-ADP-ribosylation and cytoplasmic shuttling of HuR. Also by using its HNS domain, HuR undergoes dimerization/oligomerization, underlying the increased binding of HuR with proinflammatory cytokine/chemokine mRNAs and the disassociation of the miRNA-induced silencing complex from the targets. Therefore, competitively blocking the interactions of HuR with its partners may suppress proinflammatory mediator production. In this study, peptides derived from the sequence of the HuR-HNS domain were synthesized, and their effects on interfering HuR interacting with PARP1 and HuR itself were analyzed. Moreover, cell-penetrating TAT-HuR-HNS3 was delivered into human and mouse cells or administered into mouse lungs with or without exposure of TNF-α or LPS. mRNA levels of proinflammatory mediators as well as neutrophil infiltration were evaluated. We showed that TAT-HuR-HNS3 interrupts HuR-PARP1 interaction and therefore results in a lowered poly-ADP-ribosylation level and decreased cytoplasmic distribution of HuR. TAT-HuR-HNS3 also blocks HuR dimerization and promotes Argonaute 2-based miRNA-induced silencing complex binding to the targets. Moreover, TAT-HuR-HNS3 lowers mRNA stability of proinflammatory mediators in TNF-α-treated epithelial cells and macrophages, and it decreases TNF-α-induced inflammatory responses in lungs of experimental animals. Thus, TAT-HuR-HNS3 is a promising lead peptide for the development of inhibitors to treat inflammation-related diseases.

Boosting expression level of plectasin in recombinant Pichia pastoris via 2A self-processing peptide assembly.

Plectasin is a promising and potent antimicrobial peptide isolated from the fungus Pseudoplectania nigrella which has been heterologously expressed in various hosts. In this study, a four-copy cassette of plectasin was constructed via 2A peptide assembly to further increase its expression level in recombinant Pichia pastoris. The yeast transformant 4Ple-61 harboring four-copy cassette of plectasin could secrete 183.2mg/L total protein containing 60.8% of plectasin at the flask level within 120h, which was 2.3 times higher than that of the yeast transformant Ple-6 carrying one-copy cassette of plectasin. Western blot confirmed the significant peptide expression level in the transformant 4Ple-61. Furthermore, it yielded as high as 426.3mg/L total protein within 120h during a 5-L fermentation. The purified plectasin shows superior stability and good antimicrobial activity against conventional Staphylococcus aureus ATCC 26,001 and some food-borne antibiotic-resistant S. aureus strains with the MICs ranging from 8 to 32μg/mL. Therefore, the strategy based on 2A peptide assembly can enhance the expression of plectasin and further expand its application prospect. KEY POINTS: • A yeast transformant 4Ple-61 with four-copy cassette of plectasin was constructed. • The plectasin level yield by the transformant 4Ple-61 was boosted by 2.3 times. • The plectasin showed good activity against food-borne antibiotic-resistant S. aureus.

Identification of Potential Vaccine Candidates Against SARS-CoV-2 to Fight COVID-19: Reverse Vaccinology Approach.

BackgroundThe recent emergence of COVID-19 has caused an immense global public health crisis. The etiological agent of COVID-19 is the novel coronavirus SARS-CoV-2. More research in the field of developing effective vaccines against this emergent viral disease is indeed a need of the hour.ObjectiveThe aim of this study was to identify effective vaccine candidates that can offer a new milestone in the battle against COVID-19.MethodsWe used a reverse vaccinology approach to explore the SARS-CoV-2 genome among strains prominent in India. Epitopes were predicted and then molecular docking and simulation were used to verify the molecular interaction of the candidate antigenic peptide with corresponding amino acid residues of the host protein.ResultsA promising antigenic peptide, GVYFASTEK, from the surface glycoprotein of SARS-CoV-2 (protein accession number QIA98583.1) was predicted to interact with the human major histocompatibility complex (MHC) class I human leukocyte antigen (HLA)-A*11-01 allele, showing up to 90% conservancy and a high antigenicity value. After vigorous analysis, this peptide was predicted to be a suitable epitope capable of inducing a strong cell-mediated immune response against SARS-CoV-2.ConclusionsThese results could facilitate selecting SARS-CoV-2 epitopes for vaccine production pipelines in the immediate future. This novel research will certainly pave the way for a fast, reliable, and effective platform to provide a timely countermeasure against this dangerous virus responsible for the COVID-19 pandemic.

Neuroprotective effects on microglia and insights into the structure-activity relationship of an antioxidant peptide isolated from Pelophylax perezi.

Tryptophyllins constitute a heterogeneous group of peptides that are one of the first classes of peptides identified from amphibian’s skin secretions. Here, we report the structural characterization and antioxidant properties of a novel tryptophyllin‐like peptide, named PpT‐2, isolated from the Iberian green frog Pelophylax perezi. The skin secretion of P. perezi was obtained by electrical stimulation and fractionated using RP‐HPLC. De novo peptide sequencing was conducted using MALDI MS/MS. The primary structure of PpT‐2 (FPWLLS‐NH2) was confirmed by Edman degradation and subsequently investigated using in silico tools. PpT‐2 shared physicochemical properties with other well‐known antioxidants. To test PpT‐2 for antioxidant activity in vitro, the peptide was synthesized by solid phase and assessed in the chemical‐based ABTS and DPPH scavenging assays. Then, a flow cytometry experiment was conducted to assess PpT‐2 antioxidant activity in oxidatively challenged murine microglial cells. As predicted by the in silico analyses, PpT‐2 scavenged free radicals in vitro and suppressed the generation of reactive species in PMA‐stimulated BV‐2 microglia cells. We further explored possible bioactivities of PpT‐2 against prostate cancer cells and bacteria, against which the peptide exerted a moderate antiproliferative effect and negligible antimicrobial activity. The biocompatibility of PpT‐2 was evaluated in cytotoxicity assays and in vivo toxicity with Galleria mellonella. No toxicity was detected in cells treated with up to 512 µg/ml and in G. mellonella treated with up to 40 mg/kg PpT‐2. This novel peptide, PpT‐2, stands as a promising peptide with potential therapeutic and biotechnological applications, mainly for the treatment/prevention of neurodegenerative disorders.

Exploration of corn distillers solubles from selective milling technology as a novel source of plant-based ACE inhibitory protein hydrolysates

Plant-based protein concentrate (PC) was extracted from under-utilized corn distillers solubles comprising a distinctive heat-treated blend of corn and yeast proteins. Enzymolysis of PC with alcalase generated protein hydrolysate (PH) containing angiotensin converting enzyme (ACE) inhibitory peptides. A novel kinetic model is developed to elucidate enzymolysis kinetics of PC. The PH of greatest DH (∼25%) revealed maximum ACE inhibition (%). Fractionated PH (<3 kDa) had non-toxic and non-allergenic unique peptides encrypted with anti-ACE fragments. Promising bioactive peptides (PeptideRanker > 0.85) docked with ACE had free energies between −8.40 and −10.60 kcal.mol−1 greater than captopril (−6.34 kcal.mol−1). The yeast-derived RLLPF peptide interacted with all active pockets of ACE (S1, S2, S’) via hydrogen-, polar- and hydrophobic-bonds. Docking results suggested that ARG522, VAL518, TRP357, TYR523, GLU384, ALA356, ARG124, HIS387, HIS410, ASN66, and ALA354 of ACE aided in stabilizing complexes with peptides. Thus, PH could be used as antihypertensive ingredient for feed, food, or pharmaceutical industries.

Peptide-Based Vaccine against SARS-CoV-2: Peptide Antigen Discovery and Screening of Adjuvant Systems.

The SARS-CoV-2 virus has caused a global crisis, resulting in 0.5 billion infections and over 6 million deaths as of March 2022. Fortunately, infection and hospitalization rates were curbed due to the rollout of DNA and mRNA vaccines. However, the efficacy of these vaccines significantly drops a few months post immunization, from 88% down to 47% in the case of the Pfizer BNT162 vaccine. The emergence of variant strains, especially delta and omicron, have also significantly reduced vaccine efficacy. We propose peptide vaccines as a potential solution to address the inadequacies of the current vaccines. Peptide vaccines can be easily modified to target emerging strains, have greater stability, and do not require cold-chain storage. We screened five peptide fragments (B1–B5) derived from the SARS-CoV-2 spike protein to identify neutralizing B-cell peptide antigens. We then investigated adjuvant systems for efficient stimulation of immune responses against the most promising peptide antigens, including liposomal formulations of polyleucine (L10) and polymethylacrylate (PMA), as well as classical adjuvants (CFA and MF59). Immune efficacy of formulations was evaluated using competitive ELISA, pseudovirion neutralization, and live virus neutralization assays. Unfortunately, peptide conjugation to L10 and PMA dramatically altered the secondary structure, resulting in low antibody neutralization efficacy. Of the peptides tested, only B3 administered with CFA or MF59 was highly immunogenic. Thus, a peptide vaccine relying on B3 may provide an attractive alternative to currently marketed vaccines.

Host cell targeting of novel antimycobacterial 4-aminosalicylic acid derivatives with tuftsin carrier peptides

Mycobacterium tuberculosis is an intracellular pathogen and the uptake of the antimycobacterial compounds by host cells is limited. Novel antimycobacterials effective against intracellular bacteria are needed. New N-substituted derivatives of 4-aminosalicylic acid have been designed and evaluated. To achieve intracellular efficacy and selectivity, these compounds were conjugated to tuftsin peptides via oxime or amide bonds. These delivery peptides can target tuftsin- and neuropilin receptor-bearing cells, such as macrophages and various other cells of lung origin. We have demonstrated that the in vitro antimycobacterial activity of the 4-aminosalicylic derivatives against M. tuberculosis H37Rv was preserved in the peptide conjugates. The free drugs were ineffective on infected cells, but the conjugates were active against the intracellular bacteria and have the selectivity on various types of host cells. The intracellular distribution of the carrier peptides was assessed, and the peptides internalize and display mainly in the cytosol in a concentration-dependent manner. The penetration ability of the most promising carrier peptide OT5 was evaluated using Transwell-inserts and spheroids. The pentapeptide exhibited time- and concentration-dependent penetration across the non-contact monolayers. Also, the pentapeptide has a fair penetration rate towards the center of spheroids formed of EBC-1 cells.

In silico investigation of molecular targets, pharmacokinetics, and biological activities of chicken egg ovalbumin protein hydrolysates

Food-derived bioactive peptides are promising ingredients for developing functional foods and nutraceuticals due to their putative safety, low cost, and multiple health benefits. Chicken egg is considered a major source of dietary protein, lipids, vitamins, and minerals but is also highly allergenic. The aim of this work was to investigate the inherent bioactive properties of chicken ovalbumin peptides using in silico approaches. Ovalbumin was in silico hydrolyzed with gastrointestinal proteases (chymotrypsin, trypsin, and pepsin) and results indicated cleavage of the most allergenic protein with an overall 36.62% theoretical degree of hydrolysis, consisting of 132 fragments of which 65 were di-, tri-, tetra- or oligopeptides. The most represented biological targets obtained for these peptides include HLA class I histocompatibility antigen A-3, E3 ubiquitin-protein ligase XIAP, and angiotensin-converting enzyme. Notably, peptides AIVF and AVL were found to have multi-target potentials. Gene enrichment analysis showed interaction of these peptides with some kinases and transcription factors. Overall, results from binding affinity, pharmacokinetics and physicochemical properties, and therapeutic activity showed that PGF, SSL, GGL, AVL, VY, and IL are promising peptide candidates for further studies. These results are important in the design of peptide-based functional foods and therapeutic products devoid of allergenic property of ovalbumin.

Discovery of antimicrobials by massively parallelized growth assays (Mex)

The number of newly approved antimicrobial compounds has been steadily decreasing over the past 50 years emphasizing the need for novel antimicrobial substances. Here we present Mex, a method for the high-throughput discovery of novel antimicrobials, that relies on E. coli self-screening to determine the bioactivity of more than ten thousand naturally occurring peptides. Analysis of thousands of E. coli growth curves using next-generation sequencing enables the identification of more than 1000 previously unknown antimicrobial peptides. Additionally, by incorporating the kinetics of growth inhibition, a first indication of the mode of action is obtained, which has implications for the ultimate usefulness of the peptides in question. The most promising peptides of the screen are chemically synthesized and their activity is determined in standardized susceptibility assays. Ten out of 15 investigated peptides efficiently eradicate bacteria at a minimal inhibitory concentration in the lower µm or upper nm range. This work represents a step-change in the high-throughput discovery of functionally diverse antimicrobials.

Design of chemically defined synthetic substrate surfaces for the in vitro maintenance of human pluripotent stem cells: A review.

Human pluripotent stem cells (hPSCs) have the potential of long-term self-renewal and differentiation into nearly all cell types in vitro. Prior to the downstream applications, the design of chemically defined synthetic substrates for the large-scale proliferation of quality-controlled hPSCs is critical. Although great achievements have been made, Matrigel and recombinant proteins are still widely used in the fundamental research and clinical applications. Therefore, much effort is still needed to improve the performance of synthetic substrates in the culture of hPSCs, realizing their commercial applications. In this review, we summarized the design of reported synthetic substrates and especially their limitations in terms of cell culture. Moreover, much attention was paid to the development of promising peptide displaying surfaces. Besides, the biophysical regulation of synthetic substrate surfaces as well as the three-dimensional culture systems were described.