Journal of Peptide Science最新文献

Insects, a majority of animal species, rely on innate immunity and antimicrobial peptides (AMPs), which are a part of their innate immunity, to combat diverse parasites and pathogens. These peptides have applications ranging from agriculture to antimicrobial resistance (AMR). However, there is a lack of a specialized database, prompting the development of the Insect Antimicrobial Peptide Database (IAMPDB) as a pioneering comprehensive Knowledgebase dedicated to insect-derived antimicrobial peptides (IAMPs), serving as a resource for researchers and industry professionals. Curated from UniProt and associated literature(s), IAMPDB currently houses 438 curated entries of IAMPs from various insect species, spanning 10 taxonomical orders of insects. Each entry is meticulously annotated with details on peptide sequence, source organism, activities, physicochemical properties, and more. IAMPDB offers a user-friendly interface with diverse search options, interactive visualizations, and links to external databases; advanced tools, including a peptide sequence alignment toolbox and a peptide feature calculation toolbox, facilitating sequence alignment, physicochemical property calculation, and in-depth analysis. The knowledgebase is accessible online (at URL https://bblserver.org.in/iampdb/).

A divergent synthesis strategy was developed for producing various anabaenopeptins (AP) for harmful algal bloom monitoring. The synthesis involved on-resin stepwise pentapeptide assembly on a MeDbz linker then N-α-ureido amino acid attachment and cyclization. To manage N-methylated amino acids, modified coupling conditions were employed. Lysine's ε-amino group reacted with the activated MeDbz linker in a self-cleaving head-to-side chain cyclization. Cyclization conditions were optimized by screening different pH levels to control lysine α-amine cyclization and prevent hydrolysis. Global cleavage and purification afforded the pure anabaenopeptins. This approach proved effective as a general platform for anabaenopeptin synthesis, allowing rapid access to anabaenopeptins A, B, F, and oscillamide Y.

Peptides binding overexpressed breast and cervical cancer cell surface proteins can be isolated by phage display technology, and their affinity to their potential receptors can be assessed by molecular docking. We isolated 44 phage clones displaying dodecapeptides with high affinity to HeLa cervical cancer and MDA-MB-231 (MDA) breast cancer cells by repeated biopanning of an MK13 phage library and explored their affinity to specific proteins by molecular docking. Six peptides appeared repeatedly during biopanning: two with affinity to HeLa (H5/H21), and four with affinity to MDA cells (M3/M7/M15/M17). Peptide pairs M3/H5 and H1/M17 had affinity to both cell lines. A systematic review identified Annexin A2, EGFR, CD44, CD146, and Integrin alpha V as potential protein targets in HeLa cells, and Vimentin, Galectin-1, and Annexins A1 and A5 in MDA cells. Via virtual screening, we selected six peptides with the highest total docking scores: H1 (−916.32), H6 (−979.21), H19 (−1093.24), M6 (−732.21), M16 (−745.5), and M19 (−739.64), and identified that docking scores were strengthened by the protein type, the interacting amino acid side chains, and the polarity of peptides. This approach facilitates the selection of relevant peptides that could be further explored for active targeting in cancer diagnosis and treatment.

Fluorescent probes are widely used in cellular imaging and disease diagnosis. Acting as substitute carriers, fluorescent probes can also be used to help transport drugs within cells. In this study, commonly used fluorophores, TAMRA (5-carboxytetramethylrhodamine), PBA (1-pyrenebutyric acid), NBD (nitrobenzoxadiazole), OG (Oregon Green), and CF (5-carboxyfluorescein) were conjugated with the dipeptide β-Ala-Lys, the peptide moiety of the well-established peptide transporter substrate β-Ala-Lys(AMCA) (AMCA: 7-amino-4-methyl-coumarin-3-acetic acid) by modifying it with respect to side-chain length and functional end groups. The analogs were tested for transport through or inhibition of YdgR, a prototypical peptide transporter from E. coli and apparently homologous to the human PEPT1. Strikingly, none of the dipeptide-fluorophore conjugates nor minor modifications in the reporter substrate were tolerated by YdgR, indicating discrepancies to PEPT1. These findings underscore intricate substrate recognition mechanisms governing substrate recognition by YdgR.

Developing human papillomavirus (HPV) therapeutic DNA vaccines requires an effective delivery system, such as cell-penetrating peptides (CPPs). In the current study, the multiepitope DNA constructs harboring the immunogenic and conserved epitopes of the L1, L2, and E7 proteins of HPV16/18 (pcDNA-L1-L2-E7 and pEGFP-L1-L2-E7) were delivered using KALA and REV CPPs with different properties in vitro and in vivo. Herein, after confirmation of the REV/DNA and KALA/DNA complexes, their stability was investigated against DNase I and serum protease. Then, their entry into HEK-293T eukaryotic cells was analyzed by qualitative and quantitative methods. Finally, anti-tumor effects of the peptide/DNA complexes were investigated in the C57BL/6 mouse model. Based on the obtained data, the REV/DNA and KALA/DNA complexes at the N/P ratio of 5:1 demonstrated successful penetration into HEK-293T cells. Furthermore, in vivo studies represented that the REV/DNA (survival rate: 75%) and KALA/DNA (survival rate: 50%) complexes provided significant protection against C3 tumors in mice. Indeed, REV CPP exhibited a higher survival rate and lower tumor volume than KALA CPP, 50 days after the C3 challenge. These findings represented the potential of KALA and REV CPPs, especially REV, as promising gene delivery systems for developing HPV therapeutic DNA vaccine candidates.

Short neuropeptide F (sNPF) is an insect-specific neuropeptide named for its C-terminal phenylalanine. It consists of 6–19 amino acids with a conserved RLRFa structure, regulating feeding, growth, circadian rhythms, and water-salt balance in insects. Its receptor belongs to GPCR-As and binds sNPF to regulate the insect nervous system. Many research groups are evaluating sNPF for plant protection and pest control. In this study, the natural sNPF from the pea aphid (Acyrthosiphon pisum) was used as a lead compound. Five novel sNPF analogs were designed and synthesized through molecular docking and peptidomimetics, altering the N-terminal amino acid to Ser, Thr, Tyr, Leu, or Gln. Aphid bioassays showed that the analog I-3 (YLRLRFa, LC₅₀ = 1.820 mg/L) was more active than the natural Acypi-sNPF-1 and pymetrozine. The structure–activity relationship analysis indicated that N-terminal tyrosine incorporation, combined with increased ClogP and TPSA, enhanced aphidicidal activity. Furthermore, Toxtree's toxicity predictions suggest a low risk for all compounds, and a toxicity assay conducted on the honeybee (Apis mellifera) for I-3, which exhibits high aphidicidal activity, indicates that I-3 does not pose a toxicity risk to non-target organisms. Thus, I-3 can be utilized as a selective and environmentally friendly insecticide to manage pea aphids.

Peptides are molecules that consist of at least two amino acids linked by peptide bonds. The difference between peptides and proteins is primarily based on size and structure. Typically, oligopeptides consist of fewer than about 10–20 amino acids, and polypeptides consist of more than 20 amino acids, whereas proteins usually are made up more than 50 amino acids and often contain multiple peptide subunits as stated in the International Union of Pure and Applied Chemistry rules. Beyond the nutritional properties, peptides are also structural components of hormones, enzymes, toxins, and antibiotics and play several fundamental physiological roles in the body. Since the introduction of the first commercial peptide drug, insulin, peptide-based drugs have gained increased interest. So far, more than 80 peptide-based drugs have reached the market for a wide range of conditions, such as diabetes, cardiovascular diseases, and urological disorders. Meanwhile, peptides have also gained significant attention in the cosmetic industry because of their potential in boosting skin health. In this review, peptides were comprehensively summarized in the aspects of sources, function, the use of peptides in cosmetics and skin care, and indications for the delivery of cosmetic peptides.