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Background: Deoxynivalenol is one of the common fungal toxins in processed grain foods. It has the characteristic of high temperature resistance. Dietary intake of DON contaminated food can cause adverse symptoms. Its cytotoxicity is mainly associated with the expression of apoptosis and interfering with protein synthesis. Among which, caspase family proteases play a crucial role in different types of apoptosis signaling pathways. Thus, it is important to develop a platform for real-time and in situ monitoring of caspase in living cells., Results: In this paper, a polypeptide functionalized gold nanoprobe was designed for real-time and in situ detection of caspase-9 in living cells during DON induced apoptosis. Highly anisotropic gold nanostars (AuNSs) with good LSPR effect were synthesized. It could either serve as the surface enhanced Raman scattering (SERS) substrate or quench fluorescence through fluorescence resonance energy transfer (FRET). Polypeptide containing the LEHD (Leu-Glu-His-Asp) sequence was connected to AuNSs through Au-S bonds. During DON induced cell apoptosis, caspase-9 was activated, which could specifically cleave the recognition site LEHD, causing the polypeptide chain modified with Rhodamine B (Rb) signal group to fall off and move away from AuNSs, ultimately reducing the SERS signal and enhancing the fluorescence signal in the system. The experimental results showed that the nanoprobe had high sensitivity, with a linear range of 5 ng/mL to 400 ng/mL and a minimum detection limit of 0.38 ng/mL., Significance: This method achieved dual signal quantification and visualization imaging of fluorescence and SERS for caspase-9 in living cells. The application of nanomaterials has been broadened and the assay was well versatile in different human cell lines. It provided a new platform in studying the relationship between food safety and cellular homeostasis mechanisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Food-derived salty peptides have been considered promising substitutes for sodium salt. In this work, three novel salty dipeptides Asp-Pro (DP), Asp-Arg (DR), and Arg-Glu (RE) were identified from bovine bone hydrolysates. The salt reduction rates were 76.85 %, 77.28 %, and 73.72 % by the three peptides (2 mg/mL) in a NaCl concentration of 0.203 g/100 mL, respectively. According to Stevens' law, a non-linear relationship between saltiness intensity and concentration was quantified, showing a slower increase in the sensory intensity perception compared with the changes in physical concentration (β < 1). In molecular detail, electrostatic energy and van der Waals energy were the main energetic contributions to forming stable complexes. The binding of salty peptides to TMC4 was driven by hydrogen bonding and salt bridge, and the main binding sites were Glu319, Ala579, and Thr581. These results could provide new insight into the salt-enhancing property and interaction mechanism of salty peptides as novel sodium substitutes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

To elucidate the correlation between variations in thermal hysteresis activity (THA) and the physicochemical properties and structure, antifreeze peptides (AFPs) of isolated fractions (CCP-1 and CCP-2) were characterized on based peptidomics and bioinformatics. The results revealed a positive correlation between the THA of cod collagen antifreeze peptide (CCAFP) and peptide chain length, isoelectric point, and hydrophobic amino acid content. Notably, the THA of CCP-1, which has higher alkaline amino acid content, was 2.60 °C at a concentration of 10 mg/mL, significantly higher than CCP (1.90 °C) and CCP-2 (2.27 °C). Glycine, proline, and valine were the vital amino acids to the formation of hydrogen bonds. Conversely, aspartic and glutamic acids at terminal regions of AFPs tended to introduce kinks in their structures. This distortion reduced binding sites for ice crystals, thereby decreasing their THA, providing a theory for understanding the physicochemical properties and structure of AFPs that influence their THA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

This study focused on unlocking the potential of Jinhua ham-derived peptides (JHP) for enhancing saltiness. JHP (<3 kDa) was obtained through ultrafiltration and desalting, reducing the salt content by 96 %. Four peptide fractions (JHP-P1/P2/P3/P4) were isolated using Sephadex G-25 gel filtration and anion-exchange chromatography. Sensory evaluation and electronic tongue analysis revealed that JHP-P2 (0.5 mg/mL) exhibited the highest saltiness which could replace four-fold NaCl salinity. Three peptides (DL, FMSALF, and HVRRK) identified by UPLC-QTOF-MS/MS were simulated with salty taste receptors ENaC/TMC4. Results indicated that Ser84 and Phe89 of ENaC and Asn404 and Lys567 of TMC4 are crucial for peptide docking related to salty taste. Molecular dynamics simulations showed that the three peptides bind to the TMC4 and ENaC through van der Waals forces, electrostatic interactions, and hydrogen bonds. These findings establish a robust theoretical foundation for salt reduction strategies and provide novel insights into the potential applications of Jinhua ham., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

This study aimed to identify umami peptides in corn fermented powder (CFP) and investigate their umami enhancing effect. Ultrafiltration and ethanol precipitation was used to separate the umami peptides in CFP. Dynamic sensory evaluations were used to identify the peptide fraction with the intense umami taste, and the peptides in the fraction were identified by nano-liquid chromatography-tandem mass spectrometry. Subsequently, ten umami-enhancing peptide candidates were screened using an integrated virtual screening strategy. Molecular docking revealed that Ser382, Ser104, Leu334, Glu338 and Glu148 of the T1R1 and T1R3 taste receptors are important amino acid residues for binding of the ten umami peptides. Three umami peptides (VDW, WGDDP, and WPAGE) exhibited the stronger binding affinity with the umami receptors. Moreover, molecular dynamics simulation revealed that the T1R1/T1R3 formed stable complexes with the three umami peptides during the simulation. Sensory evaluation indicated that the three peptides exhibited diverse taste characteristics (detection thresholds:0.0315-0.0625 mg/mL). The sigmoid curve analysis further confirmed peptides were identified as synergistically (VDW and WGDDP) or additively (WPAGE) enhancing the umami of 3 mg/mL MSG solution. This study uncovers the mechanism of umami-peptide-driven taste in fermented corn products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study isolated a novel antioxidant peptide from black soldier fly larvae (BSFL) using enzymatic hydrolysis. Firstly, the BSFL enzymatic hydrolysate was fractionated through ultrafiltration, with the <3 kDa fraction exhibiting the strongest DPPH and ABTS radical scavenging activity. Subsequently, this fraction was further fractionated through gel filtration chromatography and RP-HPLC. Totally, 153 peptides were identified through LC-MS/MS analysis, from which a novel peptide EDEGTYKCVLS (Pep6) was screened according to activity prediction and verification. Pep6 exhibited high radical scavenging capacity and cytoprotective effect on HepG2 cells against H 2 O 2 damage, meanwhile significantly increasing the intracellular antioxidant enzymes activity. Molecular docking analysis indicated that Pep6 competitively bound to Keap1, thereby inhibiting the formation of Keap1-Nrf2 complex, ultimately protecting cells from oxidative stress damage. In this study, a novel antioxidant peptide Pep6 was identified from BSFL, and its antioxidant mechanism was elucidated, providing a theoretical basis for its use as a natural antioxidant., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Sesame is a commonly used food ingredient, yet it is one of the eight major allergens. As sesame is often consumed in various processed forms, it is important to establish methods for detecting sesame allergens in processed foods. Liquid chromatography-tandem mass spectrometry (LC-MS/MS), using characteristic peptides as biomarkers, detects multiple allergenic proteins simultaneously with high sensitivity and accuracy. Choosing robust biomarkers is beneficial for developing a specific, universal, and sensitive method. To obtain excellent peptides of sesame allergens, sixteen commercial products were used as test materials. Proteins from these materials were extracted, digested, and analyzed. Peptides were screened based on several criteria, including specificity and amino acid composition. Only peptides showing process robustness were retained. Ultimately, nine peptides were selected as the best biomarkers. Based on the above peptides, it is possible to achieve precise and high-sensitivity detection of sesame allergens in processed products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The taste mechanisms of beef umami and umami-enhancing peptides are not well understood. Therefore, novel umami and umami-enhancing peptides from beef M. semimembranosus hydrolysates were explored. Beef hydrolysates treated with Flavourzyme® showed an overall strong umami intensity compared to those treated with Alcalase®, papain, or Protamex®. The peptides were isolated via consecutive separation processes, and 31 potential umami peptides were identified. Molecular docking results showed that WGSEPIRIQ and TERGYSF had considerably low docking energies with the T1R1/T1R3 taste receptor through potential key binding sites for hydrogen bonding, including Ser48, Gly49, and Gln278 in T1R1, and Ser67, Asn68, and Arg247 in the T1R3 subunit. The taste of the identified peptides dissolved in ultrapure water was dominated by sourness. Instead, they demonstrated an umami-enhancing effect in the presence of monosodium glutamate. These results broaden our understanding of the taste mechanisms of beef umami-enhancing peptides and their potential applications as flavoring agents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Zearalenone (ZEN) is a nonsteroidal estrogenic mycotoxin with widespread contamination. Inspired by lactone hydrolases, a peptide-based enzyme mimetic material for degrading ZEN was developed by combining serine, histidine and glutamate (S/H/E) catalytic triad with pro-hydrophobic self-assembling sequences and oxyanion hole site. Chitosan hybrid membranes were prepared, followed by immobilizing enzyme mimic on the membrane surface to fabricate biocatalytic membrane reactor. The membrane reactor, with good thermal stability and high catalytic activity after repeated use, can be applied to the degradation of ZEN in food. Computer simulation studies of the degradation mechanism indicated that the carbon atom on the lactone bond within ZEN molecule was susceptible to catalytic triplex attack, leading to lactone bond broken, followed by spontaneous decarboxylation to produce dihydroxyphenyl derivatives with greatly reduced binding capacity to the estrogen receptors. This kind of peptide-based enzyme mimetic material would be very promising in degrading mycotoxins in food safety field., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Mastitis is the most important bovine disease, causing dramatic economic losses to the dairy industry, worldwide. This study explores the valorization of whey from cows affected by mastitis, through a novel separation approach. Surface Active Maghemite Nanoparticles (SAMNs) were used as magnetic baits to selectively bind bioactive peptides with potential health benefits. Advanced techniques such as HPLC and LC-MS/MS highlighted SAMN capability of isolating a restricted group of peptides, drastically diverging from the control profile (Solid Phase Extraction, SPE) and characterized by a peculiar acidic residue distribution. Most importantly, both magnetically purified and nano-immobilized peptides (SAMN@peptides) showed protective activity against oxidative stress and inflammation, when tested on Caco-2 cells; with SAMN@peptides being associated with the strongest biological effect. SAMNs exhibited excellent characteristics, they are environmentally sustainable, and their synthesis is cost-effective prompting at a scalable and selective tool for capturing bioactive peptides, with potential applications in functional foods and nutraceuticals., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The purpose of this paper is to investigate the potential prebiotic properties and proliferation mechanism of fermented milk-derived peptides. In this study, fermented milk-derived polypeptides were obtained by extraction, separation, and purification. The purified peptides were used to culture fecal flora in vitro, and the relative abundance and composition of the flora were analyzed by high-throughput 16S rRNA sequencing technology. The results showed that peptides can promote the proliferation of beneficial bacteria Lactococcus in the intestine and inhibit the proliferation of harmful bacteria Escherichia coli-Shigella. The amino acid sequence of polypeptide components was determined and synthesized in vitro to verify the proliferation of intestinal flora; the proliferation mechanism of peptides on Lactococcus lactis was studied using non-targeted LC-MS metabolomics technology. Five important peptides with molecular weights of 1000-2000 Da were identified by LC-MS: GRP1 (LTEEEK), GRP2 (ENDAPSPVM*K), GRP3 (ITVDDK), GRP4 (EAM*APK) and GRP5 (LPPPEK). The results showed that the peptides could affect the arginine biosynthesis pathway and the amino sugar and nucleotide sugar metabolism of Lactococcus lactis. In addition, the peptides increased the expression of organic acids and their derivatives in Lactococcus lactis. This study provides a research basis for expanding the potential sources of new prebiotics and also opens up a new idea for discovering new prebiotics in vitro., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In today's social environment, the objective reality of people's increasing life pressure, environmental deterioration, and enhanced ultraviolet rays caused by the destruction of the ozone layer has led to the aggravation of people's oxidative stress. Therefore, exogenous antioxidant peptides have become a hot topic in research. In the context of insufficient protein supply and resource recycling, almond meal was used as raw material in this study. As a by-product of oil processing, it has a protein content of 68 % and antioxidant-related amino acids accounted for 84.62 %, which can be used as a high-quality natural source of antioxidant peptides. Taking antioxidant activity as the only indicator, papain was screened as a hydrolase, and 7 antioxidant peptides such as YLSF, LPSYVN and SPHWNVN were separated and purified. The affinity energy of docking with Keap1-Nrf2-ARE protein molecules was -7.5--8.9 kal/mol, and hydrophobic stacking, hydrogen bonding and intermolecular forces were maintained. Seven antioxidant peptides were synthesized in solid phase, and the IC 50 values of in vitro ABTS + scavenging rates were 3.59 μg/mL-6.73 μg/mL, and the antioxidant capacity was stronger than that of glutathione and ascorbic acid. In the in vitro cellular ROS scavenging capacity, all seven peptides had the effect of scavenging intracellular ROS, among which YLSF and ESWNPRDPQF had stronger scavenging capacity than glutathione. Finally, the mouse skin staining method determined that apricot antioxidant peptides had a significant inhibitory effect on UV damage to mouse skin, and targeted proteomics was used to clarify that apricot antioxidant peptides inhibited UV damage by mainly affecting three pathways, including the base excision repair pathway. This study not only improved the economic value of processing by-products, but also obtained 7 highly active almond antioxidant peptides, tapping the potential ability of apricot antioxidant peptides to be incorporated into functional food or cosmetic formulations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Hypothesis: Lanthanide Binding Tag (LBT) peptides that coordinate selectively with lanthanide ions can be used to replace the energy intensive processes used for the separation of rare earth elements (REEs). These surface-active biomolecules, once selectively complexed with the trivalent REE cations, can adsorb to air/aqueous interfaces of bubbles for foam-based REEs recovery. Glutaraldehyde, an organic compound that is a homobifunctional crosslinker for proteins and peptides, can be used to enhance the adsorption and interfacial stabilization of lanthanide-bound peptides films., Experiments: The stability of the interfacial cross-linked films was tested by measuring their dilational and shear surface rheological properties. Surface activity of the adsorbed species was analyzed using pendant drop tensiometry, while surface density and molecular arrangement were determined using x-ray reflectivity and x-ray fluorescence near total reflection., Findings: Glutaraldehyde cross-linked REE-peptide complexes enhance the adsorption of lanthanides to air-water interfaces, resulting in thicker interfacial structures. Subsequently, these thicker layers enhance the dilational and shear interfacial rheological properties. The interfacial film stabilization and REEs extraction promoted by the cross-linker presented in this work provides an approach to integrate glutaraldehyde as a substitute of common foam stabilizers such as polymers, surfactants, and particles to optimize the recovery of REEs when using biomolecules as extractants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This study aimed to unravel the peptide profiles of six distinct yeast protein samples and identify novel umami peptides within them. Peptide characteristics analysis support the proposition that yeast protein peptide pools represent exceptional reservoirs of umami peptides. Nine potential umami peptides were screened using the iUmami&#95;SCM, UMPred-FRL, Umami&#95;YYDS, Umami-MRNN, Innovagen, Expasy-ProtParam, and ToxinPred tools. Peptides AGVEDVY, LFEQHPEYRK, AFDVQ, GPTVEEVD, NVVAGSDLR, ATNGSR, and VEVVALND (1 mg/mL) were confirmed to possess umami taste, and the first five peptides exhibited significant umami-enhancing effects on 0.35 % monosodium glutamate. Molecular docking indicated that peptide residues His, Arg, Tyr, Asp, Gln, Thr, Ser, and Glu primarily bound to His71, Ser107/109/148, Asp147/218, and Arg277 of T1R1 and Ser104/146, His145, Asp216, Tyr218, and Ala302 of T1R3 through hydrogen bonds. This study enriches the umami peptide repository for potential food additive use and establishes a theoretical foundation for exploring taste compounds in yeast proteins and their broader applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Hypoglycemic foods have attracted increasing research interest. This study prepared a hypoglycemic product from Bacillus subtilis fermented with Pyropia (PBP), which has promising industrial potential, and elucidated its hypoglycemic mechanism. The aqueous PBP solution was orange, with protein as the main functional component. In vivo experiments demonstrated that PBP could increase insulin secretion and inhibit α-glucosidase activity, resulting in a hypoglycemic effect superior to that of acarbose at the same dose. Molecular docking revealed that the peptides APPVDID, GPPDSPY, PPSSPRP, and SPPPPPA from PBP could inhibit both α-glucosidase and dipeptidyl peptidase-IV (DPP-IV) activities. Pro residues promoted PBP peptide binding to the hydrophobic pocket S1 of DPP-IV. Additionally, PBP reduced inflammation and promoted the growth of beneficial gut bacteria (Prevotellaceae&#95;UCG&#95;003, Lachnospiraceae&#95;UCG&#95;001). This study presents a novel approach for the high-value utilization of Pyropia and a new option for the production of hypoglycemic functional foods and medicines., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Fish sauce, derived from fermented fish, exhibits a notable antioxidant effect after a six-month fermentation process, and we propose that potential antioxidant peptides were present in the fish sauce. We isolated, purified, and identified potential bioactive antioxidant peptides by using fish sauce fermented for 6 months. Additionally, molecular simulation was employed to investigate the antioxidant action mechanism of these bioactive peptides. The molecular docking results revealed that FS4-1 (MHQLSKK), FS4-2 (VLDNSPER), FS4-3 (MNPPAASIK), FS6-1(VLKQAAAGR), and FS6-2 (SPDVSPRR), could dock with the Keap1 receptor. The primary force (Van der Waals' force and hydrogen bonds) and key sites (GLY509 and ALA510) of Keap1 binding to peptides were determined. The active center was located in the side chain of amino acid Met at positions C7H78 and C7H79. We here identified antioxidant peptides in fish sauce and revealed the antioxidant mechanism through molecular simulations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Nonspecific adsorption of biomolecules (notably, proteins) and bacteria from unsterilized food may occur on sensor surfaces, which is still a challenge for food safety sensing. To achieve sensitive detection of unsterilized raw-food materials, in this study, a U-shaped four-in-one peptide with the sequence Ac-FLKLLKKLL-DOPA 3 -PPPPEEKDQDKEKaa that exhibited anchoring, antifouling, antibacterial, and recognition properties was designed. The peptide-modified sensor surface effectively prevented bacterial adhesion and proliferation while resisting biomolecule adsorption (signal inhibition rate as low as 0.51 % in single-protein solutions). A highly conductive polymer layer of poly(3,4-ethylenedioxythiophene) was introduced to improve the electrochemical performance before U-shaped four-in-one peptide anchoring. The proposed sensor could accurately detect vancomycin, with a wide linear range and limit of detection of 0.05-10 μg mL -1 and 2.06 ng mL -1 (S/N = 3), respectively. Satisfactory recovery rates (101.3-105.3 %) were achieved using diluted fresh goat milk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In this study, rice husk biochar was engineered with abundant iron ion sites to enhance the enrichment of antioxidant peptides from rice protein hydrolysates through metal-chelating interactions. The π-π interactions and metal ion chelation were identified as the primary mechanisms for the enrichment process. Through peptide sequencing, four peptides were identified: LKFL (P1: Leu-Lys-Phe-Leu), QLLF (P2: Gln-Leu-Leu-Phe), WLAYG (P3: Trp-Leu-Ala-Tyr-Gly), and HFCGG (P4: His-Phe-Cys-Gly-Gly). The vitro analysis and molecular docking revealed that peptides P1-P4 possessed remarkable scavenging ability against radicals and Fe 2+ chelating ability. Notably, peptide P4 showed radical scavenging activity comparable to glutathione (GSH) against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzthiazoline-6-sulphonate (ABTS) radicals. Cellular experiments further confirmed that peptide P4 effectively protected HepG2 cells from oxidative stress-induced damage. The modified rice husk biochar proved to be an effective means for enriching rice antioxidant peptides from protein hydrolysates., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Dynamic self-assembly has significant implications in the regulation of the enzyme activities. In this study, we present a histidine-based enzyme-mimicking catalyst, formed by the self-assembly of carefully-engineered FH-based short peptides with hemin, showcasing switchable catalytic activity of hemin due to externally induced reversible inclusion of a cucurbit[7]uril-peptide hybrid. 1H NMR, ITC and theoretical simulation are employed to examine the binding affinity between the guest and host components, and UV-vis spectra are used to investigate changes in the hemin coordination environment. The histidine segment of the short peptide can be partially shielded by the cucurbituril and released following addition of the azo compound, leading to a decrease and subsequent restoration of the histidine-hemin coordination affinity and hemin activity. The photoisomeriziable nature of the azo compound enabled the activation of FHH/hemin activity to be switched on and off by exposure to different wavelengths of light. During the operation, the Phe residue remained within the cucurbituril, allowing reversible inclusion and exposure of the histidine residues. The hemin stayed connected to FHH/cucurbit[7]uril hybrid, preventing the severe aggregation of hemin and irreversible deactivation. This work may provide insights into engineering the dynamic behaviors of the cofactor-dependent catalytic assemblies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Interfacial properties determine biomaterial performances, such as cell adhesion, signal exchange, and biomineralization, which affect the tissue repair cycle and efficiency of clinical applications. Peptides, as short protein sequences that have defined functionalities, are highly stable and easy to synthesize and have enormous potential to reshape interfacial properties. However, the lack of a universal strategy for presenting peptides on various substrates substantially hinders the application of peptides. In this study, we report a facile and universal strategy for customizing desired interfacial functionalities by a well-known layer-by-layer (LbL) technique through the assembly polyphenols with positively charged short peptide-coupling functional sequences. Polyphenol-peptide interactions were elucidated in detail by assembling polyphenols and peptides possessing different characteristics (charged, uncharged, hydrophobic, and sequence length) in combination with molecular dynamics simulations, and isothermal titration calorimetry further revealed the favorable enthalpy change due to electrostatic interactions is the main driving force for assembling peptides with polyphenols. LbL coatings assembled from polyphenols and positively charged peptides exhibited good substrate generalization, stability, cell proliferation, and antioxidant properties, when prepared as hollow capsules by sacrificing the template, exhibited significant pH and ultrasound stimulation responses, which could be suitable candidates for drug carriers. Most importantly, the LbL assembly strategy of positively charged peptides could be utilized to present various functional molecules (such as arginyl-glycyl-aspartic acid (RGD), a cell adhesion motif; CM15, an antibacterial peptide; and PEG, an antifouling surface) on various substrates for customizing desired surfaces. This study not only provides new insights into the understanding and regulation of interactions between proteins/peptides and polyphenols but also paves the way toward the interfacial functionalization of biomaterials., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: All authors are agreed to publish this paper. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

The systematic annotation of novel peptides found in the venom of scorpions needs revision. The commonly used two-letter acronym with the initials of the genus and the species is not discriminative and induces confusion. A new universal five-letter abbreviated code is here proposed. With this code, every species can be unambiguously identified. The code contains the initial capital letter of the genus, followed by four letters from the species. This code discriminates the large majority of the species. For the few others from the same genus and with coinciding initial letters of the species name, a change in the fifth letter ensures uniqueness. For scorpions belonging to different genera with identical initial letters and the same exact species name, a five-letter identifier can be generated by using two letters from the genus (in uppercase) and three letters from the species (in lowercase). Following this proposal, the peptides belonging to all scorpion species can be properly annotated., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Lourival D. Possani reports financial support was provided by Consejo Nacional de Humanidades, Ciencias y Tecnologías (Conahcyt). Baltazar Becerril reports financial support was provided by Consejo Nacional de Humanidades, Ciencias y Tecnologías (Conahcyt). Gustavo Delgado-Prudencio reports financial support was provided by Consejo Nacional de Humanidades, Ciencias y Tecnologías (Conahcyt). If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Coregonus peled is rich in protein and is a plentiful resource of bioactive peptides. This study was aimed at extracting novel Angiotensin I-converting enzyme (ACE) inhibitory peptides from Coregonus peled and revealing their potential hypotensive mechanisms. This paper screened six ACE inhibitory peptides with high bioactivity, good water solubility, and ADMET properties by computerized enzyme digestion of myosin-heavy chain from Coregonus peled, and LCYPR had the greatest ACE inhibition activity (IC 50  = 47.8782 μM). There were 47 potentially critical targets of LCYPR for hypertension treatment, involving 135 biological processes (BP), 30 cellular components (CC), and 30 molecular functions (MF). The results of KEGG pathway analyse showed that the LCYPR participated in 50 pathways including the renin-angiotensin system, renin secretion, lipid and atherosclerosis, relaxin signaling pathway, IL-17 signaling pathway, atherosclerosis, fluid shear stress, and others, through the key targets such as AGT, AKT1, ACE, REN, CTSB, STAT3, PLG, SRC, MMP2, and F2 to regulate the blood pressure of organisms. In conclusion, the study obtained a novel ACE inhibitory peptide from the myosin-heavy chain of Coregonus peled and revealed the potential target and pathway of LCYPR to improve hypertension. The study provides new ideas and methods for developing novel antihypertensive peptides. The results provide a theoretical basis for developing functional foods of the Xinjiang specialty cold-water fish., Competing Interests: Declaration of competing interest The authors claim that they have any known economic interests or individual relationships that might affect the work reported in the article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The concept of mass balance is discussed as it pertains to the pharmaceutical development of therapeutic peptides. Case studies are presented demonstrating how to perform a mass balance assessment on solid drug substance and solution drug product, and the role of mass balance in the context of the overall product control strategy is discussed. Utilizing mass balance as a specification test where the result is calculated from other critical quality attribute tests, each with their own specification, offers little value as a formalized quality acceptance criterion and may create more deviations, non-value added investigations, and potential batch failures. While useful in characterizing the performance of analytical methods and as part of a rigorous understanding of the manufacturing process and control strategy development, mass balance should not be required as a specification control and should instead be demonstrated during method development and through well-designed forced degradation experiments. Analytical method variability is discussed in relation to the analytical target profile, and the overall impact of sources of variability on the mass balance calculation is described in support of this position., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Several anions present in the extracellular matrix (ECM) not only have significant physiological functions in ECM but also play an important role in regulating peptide-based self-assembly. Herein, we have employed a non-conventional approach to overcome the limitations of the positively charged Cardin-motif peptide that failed to self-assemble at physiological pH. We used a simple and elegant strategy by employing different anions such as HPO 4 2- , Cl - and I - to mask the overall surface charge of peptide. Interestingly, these anions were utilized to modulate the nanostructure formation and mechanical stiffness of peptide hydrogels owing to their differential interactions with water molecules according to the Hofmeister series. Interestingly, these anions induced hydrogels showed diverse cellular responses on two different cell lines, fibroblast and neuronal, indicating diverse application potential of the new scaffold. Thus, this study emphasizes the importance of anions to regulate the self-assembly of Cardin-motif peptide and this approach can be utilized in developing the ideal biomimetic model of ECM for futuristic applications., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Sea anemones are a rich source of peptide toxins spanning a diverse range of biological activities, typically targeting proteins such as ion channels, receptors and transporters. These peptide toxins and their analogues are usually highly stable and selective for their molecular targets, rendering them of interest as molecular tools, insecticides and therapeutics. Recent transcriptomic and proteomic analyses of the sea anemone Aulactinia veratra identified a novel 28-residue peptide, designated Avt1. Avt1 was produced using solid-phase peptide synthesis, followed by oxidative folding and purification of the folded peptide using reversed-phase high-performance liquid chromatography. The liquid chromatography-mass spectrometry profile of synthetic Avt1 showed a pure peak with molecular mass 6 Da less than that of the reduced form of the peptide, indicating the successful formation of three disulfide bonds. The solution structure determined by NMR revealed that Avt1 adopts an inhibitor cystine knot (ICK) fold, in which a ring is formed by two disulfide bonds with a third disulfide penetrating the ring to create the pseudo-knot. This structure provides ICK peptides with high structural, thermal and proteolytic stability. Consistent with its ICK structure, Avt1 was resistant to proteolysis by trypsin, chymotrypsin and pepsin, although it was not a trypsin inhibitor. Avt1 at 100 nM showed no activity in patch-clamp electrophysiological assays against several mammalian voltage-gated ion channels, but has structural features similar to toxins targeting insect sodium ion channels. Although sequence homologues of Avt1 are found in a number of sea anemones, this is the first representative of this family to be characterised structurally and functionally., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the results reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Anticancer therapies with cisplatin and volasertib (BI-6727) were monitored by fluorescence lifetime imaging microscopy (FLIM) in live SK-Mel-2 melanoma cells. A CdSe/ZnS quantum dot functionalized with a peptide containing D-penicillamine and histidine (CdSe/ZnS-PH) was used as intracellular pH fluorescent probe. A faster cytosol acidification was observed for cells treated with cisplatin when compared to volasertib. The first changes in the intracellular pH were found after 2 hours of treatment with cisplatin and 8 hours with volasertib. Additionally, the relationship between cytosol acidification and apoptosis was investigated using an innovative methodology based on time-resolved fluorescence measurements. Similar low percentages of apoptotic cells were observed after short incubation periods (2 - 8 hours) with both drugs. In contrast, late apoptosis and death were found for a large fraction of cells during 24-hour incubation with cisplatin but not volasertib. Thus, the early acidification observed in cisplatin treatment could accelerate apoptosis and cell death. Despite volasertib treatment shows slower mechanism of action than cisplatin, similar inhibitory effects were found for both drugs at longer incubation periods (72 hours). This study proves the potential of CdSe/ZnS-PH nanoparticle as a fluorescence lifetime probe in the study of the mechanism of action of antitumor drugs., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ivan Bravo reports financial support was provided by Junta de Comunidades de Castilla-La Mancha. Andres Garzon-Ruiz reports financial support was provided by Spain Ministry of Science and Innovation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Fungal infections are becoming an increasingly serious challenge in clinic due to the increase in drug resistance and the lack of anti-fungal drugs. Vaccination is a useful approach to prevent fungal infections. However, the balance between effectiveness and side effects presents a challenge in vaccine development. In this work, we designed a plant virus-based conjugate vaccine. The non-infectiveness and innate immunogenicity of plant viruses make this vaccine both safe and effective. By conjugating a fungal antigenic peptide to the tobacco mosaic virus (TMV), the resultant vaccine improved the uptake efficiency of antigenic peptides by antigen-presenting cells and enhanced the ability to target lymph nodes. The results of in vivo vaccination in mice showed a significant increase of antigen-specific IgG antibody levels induced by the TMV conjugate vaccine. This work suggests that TMV conjugate vaccines may become a potential vaccine candidate for preventing fungal infections., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Advanced diagnostic materials, such as aptamers, are required due to the scarcity of efficient diagnostic antibodies and the low sensitivity of rapid diagnostic kits at detecting the malaria parasite, Plasmodium falciparum., Methods: Two peptides M2.9 [(KPTAEQTESPELQSAPEN) and M2.17 (KILFNVYSPLGCTCECWV)] were designed using simple epitope prediction tools and modified against the merozoite surface antigen 2 of P. falciparum (Pf.MSP2) by 3-dimensional modeling based on binding affinity. Based on five prediction tools for hydropathy, M2.17 was selected as an appropriate capture peptide. A peptide-based fluorescence-linked immunosorbent assay (FLISA) and a peptide pair-based fluorescent immunochromatographic test strip (FICT) were developed to detect P. falciparum 3D7 (drug-sensitive) and P. falciparum K1 (multi drugs-resistant) strains., Results: Bioinformatic analysis of two peptides demonstrated the potential binding affinity with the merozoite surface protein 2 of P. falciparum (Pf.MSP2) with a positive hydropathy value. The limit of detection (LOD) of FLISA was 10 parasites/μL and of a peptide pair-linked rapid FICT system was 5 and 200 parasites/μL for P. falciparum 3D7 and K1, respectively. Compared to commercial rapid detection systems (RDTs), a peptide pair-linked FICT system exhibited a 20-fold greater efficiency in detecting P. falciparum 3D7 and specifically discriminated another protozoan spp., Conclusion: A peptide pair-linked rapid diagnostic strip could be an alternative to conventional RDTs for monitoring wild-type and drug-resistant malaria parasites., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Seon-Ju Yeo, Hyun Park reports financial support was provided by National Research Foundation of Korea. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Fortification of human milk (HM) is often necessary to meet the nutritional requirements of preterm infants. The present experiment aimed to establish whether the supplementation of HM with either an experimental donkey milk-derived fortifier containing whole donkey milk proteins, or with a commercial bovine milk-derived fortifier containing hydrolyzed bovine whey proteins, affects peptide release differently during digestion. The experiment was conducted using an in vitro dynamic system designed to simulate the preterm infant's digestion followed by digesta analysis by means of LC-MS-MS. The different fortifiers did not appear to influence the cumulative intensity of HM peptides. Fortification had a differential impact on the release of either donkey or bovine bioactive peptides. Donkey milk peptides showed antioxidant/ACE inhibitory activities, while bovine peptides showed opioid, dipeptil- and propyl endo- peptidase inhibitory and antimicrobial activity. A slight delay in peptide release from human lactoferrin and α-lactalbumin was observed when HM was supplemented with donkey milk-derived fortifier., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Laura Cavallarin has patent #Food Composition - EP 3057450 B1 issued to n.a. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

This study isolated a novel peptide MMGGED with strong calcium-binding capacity from defatted walnut meal and synthesized a novel peptide‑calcium chelate COS-MMGGED-Ca with high stability via glycation. Structural characterization and computer simulation identified binding sites, while in vitro digestion stability and calcium transport experiments explored the chelate's properties. Results showed that after glycation, COS-MMGGED bound Ca 2+ with 88.75 ± 1.75 %, mainly via aspartic and glutamic acids. COS-MMGGED-Ca released Ca 2+ steadily (60.27 %), with thermal denaturation temperature increased by 18 °C and 37 °C compared to MMGGED-Ca, indicating good processing performance. Furthermore, COS-MMGGED significantly enhanced Ca 2+ transport across Caco-2 monolayers, 1.13-fold and 1.62-fold higher than CaCl 2 and MMGGED, respectively, at 240 h. These findings prove glycation enhances structural properties, stability, calcium loading, and transport of peptide‑calcium chelates, providing a scientific basis for developing novel efficient calcium supplements and high-value utilization of walnut meal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Peptides have attracted great interest as platforms for the design of nanocomposite hydrogels due to their distinct bioactivity, biofunctionality and biocompatibility. Previously, we have reported on a family of peptides that self-assembled to form stabilised three-dimensional hydrogel networks, displaying potent antimicrobial activity. In this paper, we report on the use of these hydrogelator sequences and their analogues as stabilisers and growth controllers to synthesise anisotropic gold nanoparticles (AuNPs) of different sizes and shapes. In particular, hollow spherical nanoparticles were obtained for HG2.81-AuNPs, whereas hexagonal nanoparticles were observed for TOH&#95;1N-AuNPs and PentaOH-AuNPs in their respective hydrogel networks. The PentaOH-AuNPs' hydrogel exhibited excellent results with high antimicrobial potency against Staphylococcus aureus and Pseudomonas aeruginosa ATCC 27853 and negligible cytotoxicity. On the other hand, TOH&#95;1N-AuNPs showed no antibacterial activity and no cytotoxicity, demonstrating the versatility of these peptides. This work gives credence towards the development of these materials towards further applications such as in tissue culture technology and wound dressing materials., (© 2024 The Author(s). Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd.)

Mesenchymal stem cells (MSCs) are expected to be useful therapeutics in osteoarthritis (OA), the most common joint disorder characterized by cartilage degradation. However, evidence is limited with regard to cartilage repair in clinical trials because of the uncontrolled differentiation and weak cartilage-targeting ability of MSCs after injection. To overcome these drawbacks, here we synthesized CuO@MSN nanoparticles (NPs) to deliver Sox9 plasmid DNA (favoring chondrogenesis) and recombinant protein Bmp7 (inhibiting hypertrophy). After taking up CuO@MSN/Sox9/Bmp7 (CSB NPs), the expressions of chondrogenic markers were enhanced while hypertrophic markers were decreased in response to these CSB-engineered MSCs. Moreover, a cartilage-targeted peptide (designated as peptide W) was conjugated onto the surface of MSCs via a click chemistry reaction, thereby prolonging the residence time of MSCs in both the knee joint cavity of mice and human-derived cartilage. In a surgery-induced OA mouse model, the NP and peptide dual-modified W-CSB-MSCs showed an enhancing therapeutic effect on cartilage repair in knee joints compared with other engineered MSCs after intra-articular injection. Most importantly, W-CSB-MSCs accelerated cartilage regeneration in damaged cartilage explants derived from OA patients. Thus, this new peptide and NPs dual engineering strategy shows potential for clinical applications to boost cartilage repair in OA using MSC therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The mechanical properties and bioactive motif densities of extracellular matrix materials play crucial roles in regulating cell behaviors, such as cell adhesion, migration, proliferation, and differentiation. However, current studies on cellular responses to ECM predominantly concentrated on polymer hydrogels featuring a single factor, such as the mechanical strength, the types of bioactive motifs, and the morphology of the polymers. This limited focus may overlook the complex interplay of multiple factors. Here, we developed dual gradient peptide Q 3 GT-I 3 K hydrogels with tunable mechanical strength (0.3–4.0 kPa) and different density of bioactive motif (0.45–3.67 mM) by enzymatic crosslinking. These hydrogels can mimic the viscoelasticity of natural soft tissues. The properties of mechanical strength and cell responsive motif density could be controlled by modulating the proportion of the substrates in the enzymatic reaction. MC3T3 cells significantly differentiated into osteoblasts after seeded on the Q 3 GT-I 3 K hydrogel (2.8 kPa, 1.83 mM Q 3 GT) for 21 days, identifying from the elevated expression of alkaline phosphatase and substantial calcium nodule formation. Importantly, the engineered hydrogels exert a synergistic effect on the cell behaviors such as early adhesion, late proliferation, and differentiation of MC3T3-E1 cells. This paper introduces a new strategy for designing tissue engineering scaffold materials with specific functions. • Q 3 GT-I 3 K hydrogel with adjustable mechanical strength and bioactive density were prepared by TGase crosslinking. • Q 3 GT-I 3 K hydrogel have similar viscoelastic properties to natural soft tissues, control osteoblast differentiation. • Mechanical strength and bioactive density of Q 3 GT-I 3 K hydrogel exhibit a synergistic effect on MC3T3-E1 cell differentiation. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has exposed a number of key challenges that need to be urgently addressed. Mass spectrometric studies of blood plasma proteomics provide a deep understanding of the relationship between the severe course of infection and activation of specific pathophysiological pathways. Analysis of plasma proteins in whole blood may also be relevant for the pandemic as it requires minimal sample preparation. The frozen whole blood samples were used to analyze 203 plasma proteins using multiple reaction monitoring (MRM) mass spectrometry and stable isotope-labeled peptide standards (SIS). A total of 131 samples (FRCC, Russia) from patients with mild (n=41), moderate (n=39) and severe (n=19) COVID-19 infection and healthy controls (n=32) were analyzed. Levels of 94 proteins were quantified and compared. Significant differences between all of the groups were revealed for 44 proteins. Changes in the levels of 61 reproducible COVID-19 markers (SERPINA3, SERPING1, ORM1, HRG, LBP, APOA1, AHSG, AFM, ITIH2, etc.) were consistent with studies performed with serum/plasma samples. The best-performing classifier built with 10 proteins achieved the best combination of ROC-AUC (0.97–0.98) and accuracy (0.90–0.93) metrics and distinguished patients from controls, as well as patients by severity. Here, for the first time, frozen whole blood samples were used for proteomic analysis and assessment of the status of patients with COVID-19. The results obtained with frozen whole blood samples are consistent with those from plasma and serum. [ABSTRACT FROM AUTHOR]