Search Results (262)

Recombinant protein hydrogels have emerged as transformative biomaterials that overcome the bioinertness and unpredictable degradation of traditional synthetic systems by leveraging genetically engineered backbones, such as elastin-like polypeptides, SF, and resilin-like polypeptides, to replicate extracellular matrix (ECM) dynamics and enable programmable functionality. Constructed through a hierarchical crosslinking strategy, these hydrogels integrate reversible physical interactions with covalent crosslinking approaches, collectively endowing the system with mechanical strength, environmental responsiveness, and controlled degradation behavior. Critically, molecular engineering strategies serve as the cornerstone for functional precision: domain-directed self-assembly exploits coiled-coil or β-sheet motifs to orchestrate hierarchical organization, while modular fusion of bioactive motifs through genetic encoding or site-specific conjugation enables dynamic control over cellular interactions and therapeutic release. Such engineered designs underpin advanced applications, including immunomodulatory scaffolds for diabetic wound regeneration, tumor-microenvironment-responsive drug depots, and shear-thinning bioinks for vascularized bioprinting, by synergizing material properties with biological cues. By uniting synthetic biology with materials science, recombinant hydrogels deliver unprecedented flexibility in tuning physical and biological properties. This review synthesizes emerging crosslinking paradigms and molecular strategies, offering a framework for engineering next-generation, adaptive biomaterials poised to address complex challenges in regenerative medicine and beyond. Full article

The synthesis of novel biodegradable polymers as non-viral vectors remains one of the challenging tasks in the field of gene delivery. In this study, the synthesis of the polysaccharide-g-polypeptide copolymers, namely, hyaluronic acid-g-polylysine (HA-g-PLys), using a copper-free strain-promoted azide-alkyne cycloaddition reaction was proposed. For this purpose, hyaluronic acid was modified with dibenzocyclooctyne moieties, and poly-L-lysine with a terminal azido group was obtained using ring-opening polymerization of N-carboxyanhydride of the corresponding protected amino acid, initiated with the amino group azido-PEG₃-amine. Two HA-g-PLys samples with different degrees of grafting were synthesized, and the structures of all modified and synthesized polymers were confirmed using ¹H NMR and FTIR spectroscopy. The HA-g-PLys samples obtained were able to form nanoparticles in aqueous media due to self-assembly driven by electrostatic interactions. The binding of DNA and model siRNA by copolymers to form polyplexes was analyzed using ethidium bromide, agarose gel electrophoresis, and SybrGreen I assays. The hydrodynamic diameter of polyplexes was ˂300 nm (polydispersity index, PDI ˂ 0.3). The release of a model fluorescently-labeled oligonucleotide in the complex biological medium was significantly higher in the case of HA-g-PLys as compared to that in the case of PLys-based polyplexes. In addition, the cytotoxicity in normal and cancer cells, as well as the ability of HA-g-PLys to facilitate intracellular delivery of anti-GFP siRNA to NIH-3T3/GFP+ cells, were evaluated. Full article

Seafood (fish, crustacean, and mollusk) allergy represents a critical global health issue. Food processing offers a viable strategy for allergenicity mitigation and serves as a critical intervention for seafood allergy prevention. This paper reviews recent advances in seafood allergen research, with particular focus on molecular properties, epitopes, and structure–allergenicity relationships, which are foundations for designing processing technologies to mitigate allergenicity. Furthermore, an analysis of how various food processing techniques modulate allergen structures and epitopes, ultimately affecting their allergenicity, was conducted. Current World Health Organization (WHO)/International Union of Immunological Societies (IUIS) listings include 44 fish allergens and 60 shellfish allergens, with their characterization enabling targeted processing approaches for allergenicity elimination. Physical processing techniques, including thermal and non-thermal treatment, can dramatically influence the conformational and linear epitopes by altering or destroying the structure of an allergen. Chemistry-based processing techniques (enzymatic-catalyzed cross-linking and glycation), which induce covalent/non-covalent interactions between allergens and various modifiers, can effectively mask epitopes through molecular complexation. Biological processing attenuates allergenicity by inducing protein unfolding, polypeptide chain uncoiling, and enzymatic degradation. Nevertheless, the structure–activity relationship of seafood allergens remains insufficiently elucidated, despite its critical role in guiding processing technologies for allergenicity elimination and elucidating the fundamental mechanisms involved. Full article

Organic anion transporting polypeptide 1B1 (OATP1B1) is selectively expressed at the basolateral membrane of human hepatocytes and plays a crucial role in the absorption of various xenobiotic compounds, including many important clinical drugs. Oligomerization with regulatory proteins is a common mechanism for regulating membrane protein functions. In the present study, we found that knocking down the scaffold protein radixin, which is the major member of the ERM family expressed in the liver, significantly enhanced the uptake function of OATP1B1. On the other hand, the overexpression of the phospho-mimic form of radixin (radixin-D) reduced the uptake function and cell surface level of OATP1B1, while the wild-type and phospho-dormant form of radixin (radixin-A) did not exhibit the same effect. Further investigation revealed that radixin interacts with OATP1B1. Activation of protein kinase C (PKC), which our previous study showed accelerates the internalization of OATP1B1, was found to increase the phosphorylation level of radixin associated with OATP1B1. The knockdown of radixin significantly diminished the suppressive effect of PKC on the function and cell surface levels of OATP1B1. These results suggested that OATP1B1 forms complexes with radixin, which may be phosphorylated by PKC, leading to reduced cell surface expression and activity of the transporter. Full article

Glu-Phe-Asp (GFD) proteinoids represent a class of synthetic polypeptides capable of self-assembling into microspheres, fibres, or combinations thereof, with morphology dramatically influencing their electrical properties. Extended recordings and detailed waveforms demonstrate that microspheres generate rapid, nerve-like spikes, while fibres exhibit consistent and gradual variations in voltage. Mixed networks integrate multiple components to achieve a balanced output. Electrochemical measurements show clear differences. Microspheres have a low capacitance of $1.926\pm 5.735$$\mathsf{\mu }$F. They show high impedance at $6646.282\pm 178.664$ Ohm. Their resistance is low, measuring 15,830.739 ± 652.514 m$\mathsf{\Omega }$. This structure allows for quick ionic transport, leading to spiking behaviour. Fibres show high capacitance ($9.912\pm 0.171$$\mathsf{\mu }$F) and low impedance ($209.400\pm 0.286$ Ohm). They also have high resistance (163,067.613 ± 9253.064 m$\mathsf{\Omega }$). This combination helps with charge storage and slow potential changes. The 50:50 mixture shows middle values for all parameters. This confirms that hybrid electrical properties have emerged. The differences come from basic structural changes. Microspheres trap ions in small, round spaces. This allows for quick release. In contrast, fibers spread ions along their length. This leads to slower wave propagation. In mixed systems, diverse voltage zones emerge, suggesting cooperative dynamics between morphologies. This electrical polymorphism in simple proteinoid systems may explain complexity in biological systems. This study shows that structural polymorphism in GFD proteinoids affects their electrical properties. This finding is significant for biomimetic computing and sheds light on prebiotic information-processing systems. Full article

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide that plays significant regulatory roles in the differentiation of the central nervous system and peripheral organs. A lack of the neuropeptide can lead to abnormalities in long bone development. In callus formation, a possible signaling balance shift in PACAP KO mice has been demonstrated, but Notch signalization, with its potential connection with PACAP 1-38, has not been investigated in ossification. Our main goal was to show connections between PACAP and Notch signaling in osteogenesis. Notch signalization showed an elevation in the long bones of PACAP-gene-deficient mice, and it was also elevated during the PACAP 1-38 treatment of UMR-106 and MC3T3-E1 osteogenic cells. Moreover, the inhibition of Notch signaling was compensated by the addition of PACAP 1-38 in vitro. The inorganic and organic matrix production of UMR-106 cells was increased during PACAP 1-38 treatment under the inhibition of Notch signaling. As a possible common target, the expression and nuclear translocation of NFATc1 transcription factor was increased during the disturbance of PACAP and Notch signaling. Our results indicate a possible synergistic regulation during bone formation by PACAP and Notch signalization. The crosstalk between Notch and PACAP signaling pathways highlights the complexity of bone development and homeostasis. Full article

Obesity, insulin resistance, type 2 diabetes mellitus (T2DM) and metabolic syndrome have been largely correlated to a reduction in bacterial load and diversity, resulting in a condition known as intestinal dysbiosis. The recent emergence of novel antidiabetic medications has been demonstrated to exert a favourable influence on the composition of the intestinal microbiota. Incretin-based therapy exerts a multifaceted influence on the composition of the gut microbiota, leading to alterations in bacterial flora. Of particular significance is the capacity of numerous metabolites produced by the gut microbiota to modulate the activity and hormonal secretion of enteroendocrine cells. This review examines the effects of dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide 1 (GLP-1) receptor agonists and GLP-1/gastric inhibitory polypeptide (GIP) receptor dual agonists on the composition of the gut microbiota in both mice and human subjects. The nature of this interaction is complex and bidirectional. The present study demonstrates the involvement of the incretinic axis in modulating the microbial composition, with the objective of providing novel preventative strategies and potential personalised therapeutic targets for obesity and T2DM. Full article

This review explores the mechanisms by which Human Immunodeficiency Virus type 1 (HIV-1) regulatory proteins manipulate host cellular pathways to promote viral replication and immune evasion. Key viral proteins, such as Nef, Vpu, Vif, Vpr, and Env, disrupt immune defenses by downregulating surface molecules such as CD4 (Cluster of Differentiation 4) and Major Histocompatibility Complex (MHC) class I, degrading antiviral enzymes like APOBEC3G (Apolipoprotein B mRNA editing catalytic polypeptide-3G) and SAMHD1 (Sterile Alpha Motif and Histidine Aspartate domain-containing protein 1), and counteracting restriction factors including BST-2 (Bone Marrow Stromal Antigen 2)/Tetherin and SERINC5 (Serin Incorporator 5). These interactions support viral persistence and contribute to the establishment of chronic infection. Emerging therapeutic strategies aim to disrupt these HIV-host interactions to restore innate antiviral responses and enhance immune clearance. Approaches such as stabilizing host restriction factors or blocking viral antagonists offer a promising alternative to conventional antiretroviral therapy. By targeting host-dependent pathways, these interventions may reduce drug resistance, tackle latent reservoirs, and provide a pathway toward sustained viral remission or functional cure. Full article

Type 2 Diabetes (T2D) is a complex metabolic disorder that affects multiple organs, leading to severe complications in the pancreas, kidneys, liver, and heart. Prolonged hyperglycemia, along with oxidative stress and chronic inflammation, plays a crucial role in accelerating tissue damage, significantly increasing the risk of diabetic complications such as nephropathy, hepatopathy, and cardiovascular disease. This review evaluates the protective effects of various antidiabetic treatments on organ tissues affected by T2D, based on findings from experimental animal models. Metformin, a first-line antidiabetic agent, has been widely recognized for its ability to reduce inflammation and oxidative stress, thereby mitigating diabetes-induced organ damage. Its protective role extends beyond glucose regulation, offering benefits such as improved mitochondrial function and reduced fibrosis in affected tissues. In addition to traditional therapies, new classes of antidiabetic drugs, including sodium-glucose co-transporter-2 inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists not only improve glycemic control but also exhibit nephroprotective and cardioprotective properties by reducing glomerular hyperfiltration, oxidative stress, and inflammation. Similarly, GLP-1 receptor agonists have been associated with reduced hepatic steatosis and enhanced cardiovascular function. Preclinical studies suggest that tirzepatide, a dual GLP-1/gastric inhibitory polypeptide receptor agonist may offer superior metabolic benefits compared to conventional GLP-1 agonists by improving β-cell function, enhancing insulin sensitivity, and reducing fatty liver progression. Despite promising preclinical results, differences between animal models and human physiology pose a challenge. Further clinical research is needed to confirm these effects and refine treatment strategies. Future T2D management aims to go beyond glycemic control, emphasizing organ protection and long-term disease prevention. Full article

Growing interest in incretin-based therapies for diabetes mellitus has led to an increased evaluation of their potential effects on cancer development. This review aims to synthesize recent evidence regarding the relationship between incretin-based therapies and cancer risk. We conducted a comprehensive literature review focusing on studies investigating dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and dual GLP-1/glucose-dependent insulinotropic polypeptide (GIP) receptor agonists in relation to various malignancies. Current findings suggest that while these therapies demonstrate potential benefits, including weight reduction and metabolic regulation, concerns remain regarding their long-term safety profile. Notably, some studies indicate an increased risk of thyroid and pancreatic cancers, while others report protective effects against prostate, colorectal, and breast cancers. Given the complexity of their effects, further long-term studies and post-marketing surveillance are warranted. This review highlights the need for careful clinical assessment when prescribing incretin-based therapies to patients who may be at increased risk of cancer. Full article

The construction of artificial microorganisms often relies on the transfer of genomes from donor to acceptor cells. This synthetic biology approach has been considerably fostered by the J. Craig Venter Institute but apparently depends on the use of microorganisms, which are very closely related. One reason for this limitation of the “creative potential” of “classical” transformation is the requirement for adequate “fitting” of newly synthesized polypeptide components, directed by the donor genome, to interacting counterparts encoded by the pre-existing acceptor genome. Transformation was introduced in 1928 by Frederick Griffith in the course of the demonstration of the instability of pneumococci and their conversion from rough, non-pathogenic into smooth, virulent variants. Subsequently, this method turned out to be critical for the identification of DNA as the sole matter of inheritance. Importantly, the initial experimental design (1.0) also considered the inheritance of both structural (e.g., plasma membranes) and cybernetic information (e.g., metabolite fluxes), which, in cooperation, determine topological and cellular heredity, as well as fusion and blending of bacterial cells. In contrast, subsequent experimental designs (1.X) were focused on the use of whole-cell homogenates and, thereafter, of soluble and water-clear fractions deprived of all information and macromolecules other than those directing protein synthesis, including outer-membrane vesicles, bacterial prions, lipopolysaccharides, lipoproteins, cytoskeletal elements, and complexes thereof. Identification of the reasons for this narrowing may be helpful in understanding the potential of transformation for the creation of novel microorganisms. Full article

Epitalon, also known as Epithalon or Epithalone, is a tetrapeptide, Ala-Glu-Asp-Gly (AEDG), which was synthesized based on the amino acids composition of Epithalamin, a bovine pineal gland extract, prior to its discovery in pineal gland polypeptide complex solution. During the last 25 years, this compound has been extensively studied using in vitro, in vivo, and in silico methods. The results of these studies indicate significant geroprotective and neuroendocrine effects of Epitalone, resulting from its antioxidant, neuro-protective, and antimutagenic effects, originating from both specific and nonspecific mechanisms. Although it has been demonstrated that Epitalon exerts, among other effects, a direct influence on melatonin synthesis, alters the mRNA levels of interleukin-2, modulates the mitogenic activity of murine thymocytes, and enhances the activity of various enzymes, including AChE, BuChE, and telomerase, it remains uncertain whether these are the sole mechanisms of action of this compound. Moreover, despite the considerable volume of research on the biological and pharmacodynamic characteristics of Epitalon, the quantity of physico-chemical and structural investigations of this peptide remains quite limited. This review aims to conclude the most important findings from such studies, thus presenting the current state of knowledge on Epitalon. Full article

We describe a method tailored to the in-cell selection of protease inhibitors. In this method, a target protease is co-expressed with a selective substrate, the product of which kills host cells. Therefore, the method can be applied to identify potential inhibitors based on cell host survival when inhibition of the target protease occurs. The TEV protease was chosen for this proof-of-concept experiment. The genetically encoded selective substrate is a single polypeptide chain composed of three parts: (1) a ccdB protein, which can cause host cell death when it accumulates inside the cell; (2) a protease cleavage sequence that can be changed according to the target protease, in this case the TEV substrate ENLYFQ↓G (↓-predicted cleavage site); and (3) the ssrA sequence (AANDENYALAA), which drives the polypeptide to degradation by the ClpX/ClpP complex inside host E. coli cells. In our experiment, co-expression of the active TEV protease and this selective substrate (ccdB-ENLYFQG-ssrA) caused the death of a significant host cell population, while control assays with an inactive mutant TEV Asp81Asn did not. Details of the methodology used are given, providing the basis for the application of similar systems for other proteases of interest. Full article

HUG is the HELP-UnaG recombinant fusion protein featuring the typical functions of both HELP and UnaG. In HUG, the HELP domain is a thermoresponsive human elastin-like polypeptide. It forms a shield enwrapping the UnaG domain that emits bilirubin-dependent fluorescence. Here, we recapitulate the technological development of this bifunctional synthetic protein from the theoretical background of its distinct protein moieties to the detailed characterization of its macromolecular and functional properties. These pieces of knowledge are the foundations for HUG production and application in the fluorometric analysis of bilirubin and its congeners, biliverdin and bilirubin glucuronide. These bile pigments are metabolites that arise from the catabolism of heme, the prosthetic group of cytochromes, hemoglobin and several other intracellular enzymes engaged in electron transfer, oxygen transport and protection against oxygen free radicals. The HUG assay is a powerful, user-friendly and affordable analytical tool that alone supports research at each level of complexity or taxonomy of living entities, from enzymology, cell biology and pathophysiology to veterinary and clinical sciences. Full article

Rotenone, a naturally occurring compound derived from the roots of tropical plants, is used as a broad-spectrum insecticide, piscicide, and pesticide. It is a classical, high-affinity mitochondrial complex I inhibitor that causes not only oxidative stress, α-synuclein phosphorylation, DJ-1 (Parkinson’s disease protein 7) modifications, and inhibition of the ubiquitin-proteasome system but it is also widely considered an environmental contributor to Parkinson’s disease (PD). While prodromal symptoms, such as loss of smell, constipation, sleep disorder, anxiety/depression, and the loss of dopaminergic neurons in the substantia nigra of rotenone-treated animals, have been reported, alterations of metabolic hormones and hyperinsulinemia remain largely unknown and need to be investigated. Whether rotenone and its effect on metabolic peptides could be utilized as a biomarker for its toxic metabolic effects, which can cause long-term detrimental effects and ultimately lead to obesity, hyperinsulinemia, inflammation, and possibly gut–brain axis dysfunction, remains unclear. Here, we show that rotenone disrupts metabolic homeostasis, altering hormonal peptides and promoting infiltration of inflammatory T cells. Specifically, our results indicate a significant decrease in glucagon-like peptide-1 (GLP-1), C-peptide, and amylin. Interestingly, levels of several hormonal peptides related to hyperinsulinemia, such as insulin, leptin, pancreatic peptide (PP), peptide YY (PYY), and gastric inhibitory polypeptide (GIP), were significantly upregulated. Administration of rotenone to rats also increased body weight and activated macrophages and inflammatory T cells. These data strongly suggest that rotenone disrupts metabolic homeostasis, leading to obesity and hyperinsulinemia. The potential implications of these findings are vast, given that monitoring these markers in the blood could not only provide a crucial tool for assessing the extent of exposure and its relevance to obesity and inflammation but could also open new avenues for future research and potential therapeutic strategies. Full article