Journal of Peptide Science最新文献

Various approaches to make peptides have been adopted globally owing to their high demand. The three main approaches commonly used for this purpose are solution synthesis, also called classical solution-phase peptide synthesis (CSPS), solid-phase peptide synthesis (SPPS), and liquid-phase peptide synthesis (LPPS). Each method offers unique advantages: CSPS for scalability, SPPS for automation and efficiency, and LPPS for combining solution-phase simplicity with iterative synthesis using soluble tags.

Marine sponges are sessile invertebrates found in moderate, arctic, and tropical regions, serving as a valuable reservoir of bioactive compounds, particularly Pro-rich peptides. Among these, cyclic peptides have attracted significant interest due to their diverse therapeutic properties. One notable example is Stylissatin A (SA), a Pro-rich cyclic peptide reported from the marine sponge Stylissa massa. SA and its analogues have shown promising biological activities, including anti-inflammatory, anticancer, and anti-obesity effects. Despite the vast potential of marine-derived peptides, only a small number have progressed to the pharmaceutical market. Cyclic peptides like SA offer unique opportunities for molecular modifications and total synthesis, enabling the enhancement of potency, improvement of physicochemical properties, and optimization of synthetic yields. This review highlights the synthetic strategies developed for the total synthesis of SA, explores its structural features and related analogues, and discusses their therapeutic potential, underscoring the promise of SA-based scaffolds as novel peptide-based drug candidates.

Peptide-drug conjugates (PDCs) are advancing as targeted cancer therapies, leveraging lessons from antibody-drug conjugates (ADCs) to improve tumour specificity. These molecules combine a homing peptide with a cytotoxic payload via a linker, enabling precise drug delivery while sparing healthy tissue. Despite their potential, PDCs face challenges including metabolic instability, premature payload release and rapid clearance, limiting clinical success. Only Lutathera remains FDA-approved after Pepaxto's withdrawal, though Pepaxto retains EMA and MHRA approval—highlighting regulatory and technical complexities. Most PDCs target overexpressed receptors (e.g., somatostatin and GnRH), though novel designs like CBX-12 employ alternative strategies. Currently, six PDCs are in Phase III trials, with ~96 in development, signalling growing interest. This review explores how ADC research has guided PDC optimisation, particularly in linker chemistry and payload selection. We analyse key structural features governing PDC efficacy, including peptide-receptor binding and intracellular trafficking. Innovations in stable linkers and tumour-selective activation mechanisms are critical to overcoming pharmacokinetic hurdles. Promising candidates in late-stage trials are highlighted, emphasising their potential to address unmet needs in oncology. By refining targeting precision and payload delivery, next-generation PDCs may expand treatment options for resistant cancers, bridging the gap between biologics and small-molecule therapies.

The oxidation of Met residue(s) in peptides and proteins is sometimes found in solid phase peptide synthesis (SPPS). In this study, in order to develop a method to prevent the oxidation of Met during SPPS, various sulfide compounds were added to the solvent and the oxidation rate was measured. As a result, it was found that tetrahydrothiophene (THT) was most efficient for reducing the extent of Met oxidation. THT tended to prevent the oxidation of Met in a concentration-dependent manner, although the oxidation of Met could not be completely prevented even at a concentration of 20% (v/v). On the other hand, when the SPPS in the presence of THT and then reduction of Met(O) to Met with NH₄I were performed, the yield was much improved. These results indicate that the combination of preventing oxidation with THT and reducing Met with NH₄I is effective for the synthesis of peptides containing Met residue(s). Using the method established here, we could synthesize an insulin-like peptide from the kuruma shrimp. This method is likely to be applicable to the synthesis of various Met-containing peptides.

Ubiquitylation is a highly conserved post-translational modification (PTM) in eukaryotes, which serves as a critical regulatory mechanism for protein homeostasis, cellular transport, signal transduction pathways, and numerous other functions. The biological function of ubiquitylation is dictated predominantly by the topology of its linkage. Deciphering ubiquitin's complex biochemistry necessitates novel synthetic methods that deliver well-defined, biosimilar ubiquitylation. To this end, a semisynthetic strategy relying on the recombinant expression of ubiquitin combined with chemoselective photocatalytic diselenide contraction (PDC) was established to enable site-selective biomimetic selenalysine-linked ubiquitylation. The modification of ubiquitin with a C-terminal selenol was fine-tuned to avoid hydrolysis. The conditions of the PDC reaction, such as solvent composition, phosphine concentration, and irradiation, were optimized for efficient ubiquitylation of a Tau F derived peptide. Furthermore, it was demonstrated that the selenalysine linkage undergoes efficient cleavage by deubiquitylating enzymes, comparable to the native isopeptide linkage. The presented method expands the toolbox of site-selective ubiquitylation techniques. It is tolerant to many functional groups and will help to further elucidate the complexities of ubiquitylation.

This study explores the use of a novel polymeric mesoporous support (pDVB) for solid-phase peptide synthesis (SPPS), with the aim of improving the efficiency and sustainability of the process. The pDVB support, functionalized with the Fmoc-Rink amide linker, offers advantages over conventional supports based on gel-type, lightly crosslinked polymer skeletons, particularly with regard to reduced reliance on swelling capacity, which allows the use of a wider range of solvents. The work focuses on greener and eco-friendly solvents such as TEP, ACN, IPA, and their mixtures with DMSO to replace toxic solvents such as DMF. The synthesis of two model peptide sequences, Fmoc-LLVF-NH₂ and ACP(65–74), showed that pDVB-Rink performs better than a conventional-type Rink Amide MBHA support, especially when using environmentally friendly solvents. These results suggest that mesoporous pDVB-Rink is a promising solid support for SPPS to reduce the use of toxic solvents and to improve sustainability.