α-Amino lactam (Agl) units have served as conformational constraints in peptide-based drug discovery since the pioneering studies of Freidinger and Veber [1]. In peptides, Agl residues have been shown to adopt the i + 1 position of β-turn secondary structure which play privileged roles in molecular recognition. N-Aminoimidazolone (Nai) residues offer similar means for constraining peptide backbone geometry in β- and γ-turn conformers and are apt for functionalization with substituents to study side chain orientation [2].

Our presentation discusses a general organocatalytic method for the synthesis of 4-, 5- and 4,5-substituted Nai dipeptides [3,4]. The synthesis and application of substituted Nai dipeptides will be showcased in structure-activity relationship studies of cluster of differentiation-36 receptor ligands that act as modulator of inflammation [3,4].

1. Freidinger, R. M. Design and Synthesis of Novel Bioactive Peptides and Peptidomimetics Med. Chem. 2003, 46, 5553- 5566.

2. St-Cyr D.J., García-Ramos Y., Doan N.D., Lubell W.D. Peptidomimetics I. Springer; Cham, Switzerland: 2017. Aminolactam, N-Aminoimidazolone, and N-Aminoimdazolidinone Peptide Mimics; pp. 125–175.

3. Hamdane, Y.; Poupart, J.; Lubell, W. D. Synthesis, 2022, 54 (6), 1518–1526.

4. Hamdane, Y.; Chauhan, S. P.; Vutla, S.; Mulumba, D.; Ong, H.; Lubell, W. D. Lett. 2021, 23 (9), 3491–3495.

Amyloidoses result from protein misfolding and aggregation into insoluble amyloid deposits, impairing organ function. These deposits are linked to diseases like Alzheimer's, Parkinson’s, and type 2 diabetes (T2DM). T2DM involves the pancreatic deposition of islet amyloid polypeptide (IAPP), a peptide hormone critical for glucose regulation. However, IAPP can misfold, forming cytotoxic aggregates in pancreatic islets and leading to β-cell dysfunction. Targeting IAPP aggregation is a promising treatment strategy for T2DM. Naturally occuring gallotannins are potential amyloid-aggregation inhibitors, although their effects are not fully understood. This study examines two gallotannins, corilagin and 1,3,6-tri-O-Galloyl-β-D-glucose (β-TGG), and their inhibitory effects on IAPP aggregation. Thioflavin T fluorescence, atomic force microscopy and circular dichroism showed that gallotannins delay IAPP self-assembly and reduce length and quantity of amyloid fibrils. By monitoring cell metabolism, release of cytosolic enzymes and production of reactive oxygen species, we showed that corilagin protects INS-1E pancreatic cells against IAPP toxicity and plasma membrane damage. Peptide-gallotannin interactions were further investigated using all-atom explicit solvent molecular dynamic simulations, revealing hydrogen bonds and π-π stacking interactions. Overall, these experimental and computational findings highlight the potent anti-aggregative and cytoprotective properties of gallotannins, thus, potential candidates to prevent or modulate the progression of amyloidoses.

Over the past decade, the growing field of synthetic biology has allowed the manipulation of an organism's biological system for a specific purpose. To avoid unwanted interactions, non-host molecular components can be used to create orthogonal proteins. We developed a DNA-binding protein that is orthogonal to any host system by combining bacterial and mammalian transcription factor elements. Our protein HinZip recognizes and strongly binds a large DNA site of at least 24 base pairs with high specificity and selectivity. This results in selective regulation of gene circuits by recognition of a large, unique DNA sequence inserted in the host’s genome. HinZip is easily expressed in bacterial systems, for which fewer synthetic biology tools exist. We tested HinZip in a bacterial-one-hybrid system that ties the survival of E. coli cells with HinZip binding to a target site, showcasing HinZip’s ability to function in bacterial synthetic circuits. This can be generalized to any synthetic biological system making it a versatile synthetic biology modulator.

Transdermal matrices modified with proteins and peptides containing adaptogens represent a promising approach in skin therapy and care. Adaptogens, known for their antioxidant properties and stress-resistance benefits, have been incorporated into transdermal matrices to support skin regeneration and protection. Modification with proteins and peptides enhances the stability and efficacy of active ingredient transport across the skin barrier, enabling gradual and controlled release. The study examined the physicochemical properties, stability of the matrices, and the effectiveness of adaptogens in reducing oxidative stress and supporting skin regeneration processes. Results indicate that these matrices could be an effective tool in treating inflammatory conditions and skin aging processes, opening new possibilities for applications in dermatological and cosmetic products. The potential of this technology could contribute to the development of innovative therapies that support skin health.

Acknowledgments: The project is financed with funds from the state budget granted by the Minister of Science within the framework of the "Student Scientific Clubs Create Innovations" (SKN/SP/601893/2024) "Application of Biohydrogels Containing Adaptogens in Innovative Chronic Wound Therapy" .The research work was carried out within the SMART-MAT Functional Materials Science Club (section Smart-Mat) at the Faculty of Materials Engineering and Physics of the Cracow University of Technology.

Peptide nanocarriers incorporated with adaptogens represent an innovative approach in the fields of medicine and cosmetology, offering new possibilities in therapy and skin care. Adaptogens, known for their antioxidant properties, stress resistance, and support of homeostasis, have been introduced into peptide nanocarriers to enhance their stability and effectiveness. With a carefully designed peptide structure, these nanocarriers enable precise delivery of adaptogens to cells, increasing the bioavailability of active ingredients. The study evaluated the physicochemical properties, stability, and therapeutic efficacy of the nanocarriers, demonstrating their potential in combating oxidative stress and aging processes. The results indicate the feasibility of applying this technology in future therapeutic products, particularly for the treatment of skin disorders.

Acknowledgments: The project is financed with funds from the state budget granted by the Minister of Science within the framework of the "Student Scientific Clubs Create Innovations" (SKN/SP/601893/2024) "Application of Biohydrogels Containing Adaptogens in Innovative Chronic Wound Therapy" .The research work was carried out within the SMART-MAT Functional Materials Science Club (section Smart-Mat) at the Faculty of Materials Engineering and Physics of the Cracow University of Technology.

Protein engineering is an important tool for modifying biomolecules and can be classified into two categories: rational design and directed evolution. Combined with rational design, we use Phage Assisted Non-Continuous Evolution (PANCE), in which the protein of interest (POI) is subjected to cycles of mutagenesis and selection to improve its structure and function. Due to lack of specificity and low mutation rates observed with other mutagenesis plasmids, we shifted to the eMutaT7 mutagenesis plasmid in our viral PANCE system to mutate genes. Since the cytidine deaminase in eMutaT7 is fused to T7 RNA Polymerase, the addition of the T7 promoter and terminator encourages accumulation of mutations in the POI only. We will present the application of our viral eMutaT7 Phage Assisted Evolution (eMPAE) system to evolve proteins that bind specifically to large DNA target ligands. In this way, we are optimizing our system for phage-assisted evolution toward evolving DNA-binding proteins by circumventing the limitations of other bacterial mutagenesis plasmids.

Biofunctionalities of bioactive peptides (BAPs) are sequences of 3 to 40 amino acid residues in length. These proteins, which have similar properties to those of endogenous peptide hormones, are derived from parental polypeptide sequences through controlled and specific proteolytic cleavages. In the first half of the 20^th century, BAPs fundamental to medicine were discovered, such as insulin, regarded as one of the largest scientific achievements in drug discovery for its impact on the treatment of diabetes. Novel tools are expeditiously being used to screen and target BAPs chain-based drug candidates. Molecular docking has drawn attention since its fundamental theoretical simulation capabilities in computational chemistry. It is a core method in drug research for testing how BAPs and target proteins can interact with small molecules. The algorithms simulate binding affinities to identify potential candidates, optimizing their specificity, which is essential for therapeutic safety and efficacy. Better scoring methods and their integration with structural biology not only streamline the process, but also progress the comprehension of protein-peptide relationships and aid in the discovery of more targeted and effective drugs. The review seeks assess the scope of this field and underline the crucial role that proteins play in the drug's discovery and development.

Glycans are essential carbohydrates that play a role in cell recognition, immune responses, and disease progression. Changes in glycosylation, the process of adding glycans to proteins or lipids, are linked to diseases like cancer. In cancer, altered glycosylation helps tumour cells evade the immune system. Fucosylation is one such modification that supports cancer growth and immune escape, making it a promising target for therapies. Lectins are proteins that bind specific glycans, useful in identifying and separating glycans, especially in cancer biomarkers. However, most lectins have limitations in drug development because of their size, immunogenicity, and potential toxicity. Odorranalectin (Odo), a small, fucose-binding lectin-mimicking peptide (17 amino acid residues) derived from Odorrana grahami, exhibits high affinity toward tumour-associated glycans while maintaining low immunogenicity and potential for nasal drug delivery. Using the Liquid Glycan Array (LiGA) platform (which decodes glycan-binding profiles through DNA-barcoded glycan libraries), we present a structure-activity relationship (SAR) study of Odorranalectin. This approach evaluates Odo modifications, including C- and N-terminal alterations, linker types, and Odo from D-AA (mirror structure), for optimal glycan recognition. Our findings advance the understanding of Odo’s glycan binding, offering insight into potential therapeutic applications.

In the study of peptide structure-activity relationships, the α-amino γ-lactam (Agl), so-called Freidinger-Veber lactam residues are important tools due in part to ability to favour β-turn conformers (Figure) [1]. In examinations of peptide molecular recognition, the β-amino γ-lactam (Bgl) residue has been less commonly used as the Agl counterpart but offers similar potential to stabilize turn conformers [2]. For example, notable activity has been exhibited by Bgl analogs of allosteric modulators of the interleukin-1 and the cluster of differentiation-36 receptors (IL-1R and CD-36) [2, 3]. Our presentation will describe advances in the synthesis and application of Bgl residues for studying peptide conformation and activity.

References

1. Freidinger, R. M.; Veber, D. F.; Perlow, D. S.; Brooks, J. R., Bioactive conformation of luteinizing hormone-releasing hormone: evidence from a conformationally constrained analog. Science 1980, 210 (4470), 656-658.
2. Boutard, N.; Turcotte, S.; Beauregard, K.; Quiniou, C.; Chemtob, S.; Lubell, W. D., Examination of the active secondary structure of the peptide 101.10, an allosteric modulator of the interleukin‐1 receptor, by positional scanning using β‐amino γ‐lactams. Pept. Sci. 2011, 17 (4), 288-296.
3. Boutard, N.; Jamieson, A. G.; Ong, H.; Lubell, W. D., Structure–Activity Analysis of the Growth Hormone Secretagogue GHRP-6 by α- and β-Amino γ-Lactam Positional Scanning. Biol. Drug Des. 2010, 75 (1), 40-50.

Benzotriazepines are a class of heterocycles that have exhibited binding affinity and activity at various receptors [1]. 1,3,5,8-Tetrasubstituted 1,3,4-benzotriazepin-2-ones have been shown to mimic both type I and I’ β-turn conformations due in part to nitrogen pyramidalization and dynamic chirality [2]. Moreover, biological assessment of tetrasubstituted benzotriazepinones designed to mimic the peptide allosteric modulator Urocontrin have demonstrated ability to selectively enhance or diminish the activity of one of the two endogenous urotensin II receptor ligands without influence on the activity of its counterpart [3]. Our presentation focuses on the development of a modular strategy to prepare tetrasubstituted benzotriazepinones. Notably, photoreactive components are being introduced on the heterocycle structure with the goal of creating photoaffinity probes to label the binding site of the urotensin II receptor.