International Journal of Peptide Research and Therapeutics最新文献

Angiotensin-converting enzyme-2 (ACE2) is a important cell surface receptor of SARS-CoV-2 S protein. The initial stage of SARS-COV-2 cell infection involves the binding of the S protein to ACE2. Hence, this work presents an innovative strategy to designing ACE2-based peptide inhibitors by considering the surface property and morphology of the S protein RBD. The aim is to develop a short peptide inhibitor that can effectively inhibit S protein-ACE2 interaction Through computational analysis and molecular simulation, the surface properties and morphology of S protein receptor-binding structural domain (RBD) were investigated, while the key residues of ACE2 ligand-binding structural domain (LBD) were identified based on their contributions and non-covalent interactions. Then, peptide inhibitors, consisting of ACE2 key residues, were developed by fitting to the surface characteristics and topographical features of the S protein RBD. Molecular simulation showed that two novel short peptides, IEPFF (I5) and WIEPFF (W6) had high affinity for S protein RBD but a low affinity for the cell membrane. Cellular adsorption studies demonstrated that both I5 and W6 effectively blocked ACE2-S protein binding without significant cytotoxicity. Flow cytometry analysis revealed that both I5 and W6 effectively inhibited S protein binding to the ACE2, resulting in a significant reduction (75 and 79%, respectively) in fluorescence intensity after 30 min of incubation at a concentration of 200 μM. Both I5 and W6 were excellent potential anti SARS-COV-2 drugs. This work provides an innovative perspective for the development of functional peptides for the prevention and management of SARS-COV-2.

The rapid emergence of multidrug-resistant (MDR) bacteria has motivated researchers to develop new antibiotic agents including antimicrobial adjuvants that resensitise against multidrug-resistance. In this study, four peptides, two 12-mer and two 8-mer derived from the primary structure of human glucose-dependent insulinotropic polypeptide (GIP), were synthesized by solid-phase peptide synthesis (SPPS). These peptides were designated as AO1, AO2, AO3, and AO4, respectively. Their antimicrobial activity was tested against bacteria possessing an AcrAB-TolC efflux pump system, namely Escherichia coli TG1 and Erwinia amylovora 1189. Although the peptides were shown to have no antimicrobial activity, through a synergistic action they each reduced the MIC values of the selected AcrAB-TolC antibiotic substrates by 4 to 8-fold in E. coli TG1 and 4 to 16-fold in E. amylovora 1189. The activity of synthetic peptides as AcrAB-TolC inhibitors in E. coli TG1 and E. amylovora 1189 was tested by intercellular ethidium bromide (EtBr) accumulation assay at different concentrations ranging from 12.5 to 100 µg mL^− 1. When compared to a reference efflux pump inhibitor, the four peptides each demonstrated good inhibitory action, with the optimum being 100 µg mL^− 1. Our results show these to be promising lead peptides for further development as potential antibacterial adjuvants against MDR bacteria.

Neglected tropical diseases (NTDs) are a group of at least 20 infectious diseases that primarily affect tropical regions. Despite impacting 1.6 billion people worldwide, these diseases have not received adequate global priority and attention. Currently, NTDs caused by protozoa have limited therapeutic options, and the emergence of drug-resistant strains further exacerbates the situation. In recent years, several antimicrobial peptides (AMPs) have emerged as potential therapeutic candidates against NTDs. This review analyzes the contemporary trends of AMPs, explores their antiparasitic properties, and mechanisms of action against three parasitic protozoan NTDs: Chagas disease, human African trypanosomiasis, and leishmaniasis and one parasitic helminth NTD: lymphatic filariasis. Furthermore, notable drawbacks associated with AMPs are highlighted, and future research directions are proposed. Overall, this review points out the potential of AMPs as therapeutic agents for these three protozoan neglected tropical diseases and one parasitic helminth NTDs as well as emphasizes the imperative need for continued research in this field.

Peptides are a kind of compounds formed by α-amino acids linked together by peptide bonds, which are also intermediate products of protein hydrolysis. Nowadays, they mostly come form laboratory chemical synthesis and protein degradation. Peptides are important in maintaining the normal functioning of our bodies, involved in many aspects such as nerve, homeostasis, growth and development and healing, as well as wound repair. When human skin is exposed to external mechanical, physical and chemical stimuli, it forms wounds. When the body or wound environment is in a special state (hyperglycemia, infection, etc.), the process of wound healing will be limited or even non-healing. In this review, we will introduce the peptides which can promote wound healing and describe their function after partial tissue damage in the field of sports system. In addition, we introduce peptides combined with modern tissue engineering, material science and 3D technology, which can exploit the advantages of peptides and overcome their disadvantages. Finally, we discuss the current development status and prospects of the field of peptides.

Among all health-related issues, the rising concerns about drug resistance led to the look for alternative pharmaceutical drugs that are effective against both infectious and noninfectious diseases. Antimicrobial peptides (AMPs) are small molecular peptides that play a crucial role in the innate immunity of various organisms. They have amphiphilic structure and net positive charge, allowing them to interact with membranes and hydrophobic surfaces, showing strong broad-spectrum activity against different microorganisms, including bacteria, fungi, and viruses. They also exhibit other host-beneficial activities, including immunomodulation, anti-inflammatory, tissue regeneration, etc. AMPs exhibit antimicrobial activity through wide mechanisms of action, particularly by focusing on intracellular targets to inhibit the synthesis of nucleic acids and proteins. These wide ranges of mechanisms of action of AMPs have contributed to the slow development of resistance against microorganisms. The increasing pathogen resistance is a major global public health threat, and AMPs are constantly being explored and developed as another treatment for viral diseases such as HIV infection and (COVID-19). This review analyzes the potential of AMPs to combat antimicrobial resistance developed by several antimicrobial-resistant (AMR) microorganisms against existing antibiotics. This review focuses on the highlights of the sources, synthesis, mode, and mechanism of action, the evaluation of several benefits, and the outline of various hurdles. The review has also included the possible solution to the limitations associated with the clinical applications of AMPs, along with its future perspectives and development needed in drug discovery against AMR pathogens.

Bacteriocins are membrane-acting peptides and generally kill closely related bacteria using pore formation. In this study, we have studied a bacteriocin, weissellicin LM85 from Weissella confusa LM85 to monitor its antimicrobial activity against Escherichia coli ATCC 25922. It was purified from cell-free supernatant of W. confusa LM85 with molecular weight ~ 6.5 kDa and showed minimum inhibitory concentration, 138.3 µg/mL and minimum bactericidal concentration, 553.3 µg/mL against E. coli ATCC 25922. The loss of cell-viability, tested by staining with propidium iodide, suggested bactericidal effect of weissellicin LM85. There was efflux of potassium (K⁺) ions, dissipation of membrane potential (∆ψ) and transmembrane pH gradient (∆pH) in bacteriocin-treated cells. The target cells were found swollen and ruptured when visualized under electron microscope. It inhibited range of Gram-positive and Gram-negative bacteria such as Lactiplantibacillus plantarum NRRL B-4496, Lpb. plantarum LD4, Lactobacillus acidophilus NRRL B-4495, Enterococcus faecium NRRL B-2354, E. hirae LD3, E. faecalis ATCC 29212, Pediococcus pentosaceus LB44, Vibrio sp., Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311, Shigella flexneri, Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853. The above results indicate weissellicin LM85 is a membrane-acting peptide with broad host-range of antimicrobial activity and may be used as alternative to clinical antibiotics.

Antimicrobial peptides (AMPs) have garnered attention for their differential regulation in cancers like oral squamous cell carcinomas (OSCC), suggesting their potential as novel anti-cancer agents. These small cationic peptides play crucial roles in innate immunity, particularly in the oral cavity where they are produced by salivary glands and epithelium to combat microbial invasion. AMPs exhibit antimicrobial and anti-cancer activities, disrupting microbial cell membranes and inducing cytotoxicity in cancer cells by binding to exposed phosphatidylserine moieties. Certain AMPs also trigger the release of tumor antigens and damage-associated molecular patterns. With increasing resistance to conventional chemotherapy, AMPs present a promising avenue for the development of effective therapeutic agents in oncology. In addition to their direct cytotoxic effects on cancer cells, AMPs exhibit potential in activating adaptive immunity and functioning as tumor suppressor genes. This review explores the properties, mode of action, and potential interaction of AMPs and specific cancer cells, emphasizing their role in combating oral cancer and the need for further research in this area.

We have previously shown that lyophilized mixtures of six- and twelve-melanoma peptide vaccines retain stability, purity, and amino acid sequence identity for up to five years when stored at -80 °C. However, this temperature requirement presents a significant obstacle to storage and distribution of vaccines for low-resource environments. Thus, we examined the stability of these peptides over a range of temperatures for varying durations of time. When stored at +4 °C or at room temperature for up to three months, 17 of the 18 peptides remained stable. The only change for the remaining peptide was an increase in an oxidized methionine residue. The results presented in this report support broadening the accessibility of these and other peptide-based vaccines to resources-limited communities.

The persistent development of bacterial resistance to β-lactam antibiotics presents a serious risk to public health worldwide. The ability of metallo-β-lactamases (MBLs) to hydrolyze a wide range of β-lactam antibiotics and render them ineffective makes them a difficult challenge. The identification and design of clinically useful inhibitors against MBLs like Verona integron-encoded metallo-β-lactamase-2 (VIM-2) is still challenging. In this study, we examine the inhibitory capacity of peptides against VIM-2 of Pseudomonas aeruginosa. Deriving inspiration from earlier studies on arginine-rich peptides, we hypothesized that lysine repeats with similar nature may show comparable binding with VIM-2.We found that lysine repeats are much more stable than arginine repeats, and show comparable binding with VIM-2. Initially, we designed a library of peptides containing various combinations of lysine and arginine residues, with the sequence length of 30 amino acids. By means of computational modeling, Protein-Peptide docking and molecular dynamics simulations, we evaluated the stability and binding affinity of these peptides in complex with VIM-2. Peptides showing best binding with VIM-2 were subjected to optimization where length was reduced to 12 residues. This optimization was performed to reduce charge and potential toxicity, enhancing the translational prospects of the sequences. We observed that PolyKR (6) was found to be the lead candidate. We demonstrate that incorporation of KR repeats in peptide sequences can be of help in enhancing their binding affinity towards VIM-2. Further, wet-laboratory validation needs to be performed in order to study the interaction of the peptide with the VIM-2 MBL in detail.

Liver cancer is a worldwide issue that also affects the Malaysian population. The occurrence is closely related to risk factors like chronic infections and environmental exposures. Due to the toxicity of conventional therapeutic drugs for liver cancer, bioactive peptides have emerged as a popular alternative anticancer agent. Although the full-length pardaxin from Pardachirus marmoratus was proven with anticancer effects, its concurrent haemolytic effects are yet to be resolved. Therefore, this study utilized in silico and in vitro analyses to assess cytotoxic effects induced by the shortened pardaxin derivatives. The in silico findings led to the discovery of a series of shortened pardaxin derivatives with 13 amino acids, where single residue replacement prediction by bioinformatics tools was done on the shortened sequences. Among the top five shortened derivatives, the derivative where amino acid threonine was replaced by proline, was identified as the most potential candidate, namely LL13. The LL13 peptide was predicted with improved anticancer effects, non-toxic, and alleviated haemolytic effects as compared to its parental peptide. The subsequent cytotoxicity testing further validated its selective toxicity against liver cancer cells, HepG2 cells, with relatively lower killing effects on the normal cells, Vero cells. These in vitro findings validated the in silico predictions and also indicated that this peptide has potential as an anticancer drug with selective targeting capabilities. In conclusion, this study has highlighted the potential of using a combination of in silico and in vitro approaches to discover potentially shortened peptides as a novel therapeutic option for liver cancer treatment.