Triphenylphosphonium (TPP) derivatives of a decapeptide related to sequences of bactenecin 7 (Bac7) and oncocin (Onc112) were synthesized and studied as potential antimicrobial compounds using various biochemical and microbiological assays. It was shown that while the reduction of the Bac7 length to 10 a.a. residues dramatically decreases the affinity to bacterial ribosomes, the modification of peptide with alkyl-TPP moieties leads to an increase in the affinity. New analogs which structure combines a decapeptide related to Bac7 and Onc112 — Bac(1-10, R/Y) — and TPP, attached to the C-terminal amino acid residue through alkylamide linkers, inhibit translation in vitro and are found to be more selective inhibitors of bacterial translation as compared with eukaryotic translation, than Onc112 and Bac7. Triphenylphosphonium analogs of a decapeptide related to Bac7 and Onc112 suppress the growth of both gram-negative bacteria, similar to Onc112 and Bac7, and gram-positive ones as alkyl-TPP derivatives, and also act against some resistant laboratory strains. Bac(1-10, R/Y)-C2-TPP, containing a short alkylamide linker between the decapeptide and TPP, is transferred into the E. coli cells via the SbmA transporter protein. TPP derivatives of the decapeptide Bac(1-10, R/Y) containing either decylamide or ethylamide linker cause B. subtilis membrane depolarization, similar to alkyl-TPP. The Bac(1-10, R/Y)-C2-TPP analog is proved to be non-toxic for mammalian cells by MTT-test.

The receptor tyrosine kinase (EphB4), which produces erythropoietin, was identified as a molecular target for cancer. We identified six peptides as potential inhibitors of EphB4 using an integrated approach combining online bioinformatics tools. According to PeptideRanker, CSM-peptides, SCMTHP, and AcPEP analysis, all peptides are effective against cancer, with the exception of LTAPGQATLPT and VEQNLVPGLK. Furthermore, Toxin-Pred predicts that none of the peptides are toxic, and that only VQLPGWRVFP and TMKGPPDTLQ are potentially allergenic using AllerTop server. PepSite2, HPEPDOCK, and MDockPeP servers were utilized to perform molecular docking, and PacDock was used to examine molecular interactions. The docking score (kcal/mol) range of six promising anticancer peptides against EphB4 was recorded as follows: VQLPGWRVFP (-240.72), FTKDDEWSCFPF (-201.74), SYLPPLSAEVTAK (-177.52), LTAPGQATLPT (-162.23), VEQNLVPGLK (-157.30), TMKGPPDTLQ (-149.67). The main bindings on the allosteric site to VQLPGWRVFP were with R706, S815, R819 and P843 on EphB4. Collectively, our results demonstrated that M. oleifera peptides ameliorate cancer by inhibiting EphB4, and they are promising candidates for the prevention and treatment of cancer.

Despite significant strides in prevention, diagnosis, and treatment, cardiovascular diseases remain the number one cause of mortality in the United States, with rates climbing at an alarming rate in the developing world. Targeted delivery of therapeutics to the heart has been a lofty goal to achieve with strategies ranging from direct intra-cardiac or intra-pericardial delivery, intra-coronary infusion, to adeno-associated viral vectors which have preference, if not complete cardio-selectivity, for cardiac tissue. Cell penetrating peptides (CPP) are 5-30 amino acid long peptides that are able to breach cell membrane barriers while carrying cargoes up to several times their size, in an intact functional form. Identified nearly three decades ago, the first of these CPPs came from the HIV coat protein transactivator of transcription. Although a highly efficient CPP, its clinical utility is limited by its robust ability to cross any cell membrane barrier, including crossing the blood-brain barrier and transducing neuronal tissue non-specifically. Several strategies have been utilized to identify cell or tissue specific CPPs, one of which is phage display. Using this latter technique, we identified a cardiomyocyte targeting peptide (CTP) more than a decade ago, a finding that has been corroborated by several independent labs across the world that have utilized CTP for myriad different purposes in pre-clinical animal models. The goal of this publication is to provide a comprehensive review of the identification, validation, and application of CTP, and outlining its potential in diagnostic and therapeutic applications especially in the field of targeted RNA interference.

The precise molecular basis of anti-tumor immunity is not yet fully understood, although commensal Bifidobacterium (c-BIF) is expected to be one of the key players in cancer control via antigenic mimicry. We investigated the sequence similarity between c-BIF and cytotoxic T lymphocyte (CTL) epitope peptides against human tumor-associated antigens to better understand the molecular basis of antigenic mimicry. We used two different similarity analyses for this purpose, a linear sequence analysis and a similarity analysis of T cell receptor (TCR)-mediated recognition of CTL epitope peptides on antigen-presenting cells. The linear sequence analysis revealed 3,900 positive numbers of similarity sites between them with 126 mean per peptide and 107 median per peptide, while the TCR-mediated recognition analysis revealed 5,018 positive numbers with a mean of 162 and median of 132 per peptide. These results demonstrated the existence of durable and abundant sequence similarities between c-BIF and CTL epitope peptides, suggesting that the former play a pivotal in inducing cellular and humoral immunity against the latter in the absence of cancer cells via antigenic mimicry.

The development of saltiness enhancement peptides is important in reducing salt intake and promoting dietary health. Our study aimed to analyze and identify straw mushroom enzymatic peptides with salty taste enhancing effects. The taste-related peptides within the straw mush-room extract were isolated via ultrafiltration and identified using UPLC-Q-TOF-MS/MS. Sub-sequent, E-tongue and sensory analyses unveiled that the ultrafiltration fraction (500-2000 Da) of straw mushroom peptides exhibited a saltiness enhancement effect. The UPLC-Q-TOF-MS/MS analysis identified 220 peptides within the ultrafiltration fractions (500-2000 Da), which were then assessed for their interaction with the T1R1/T1R3 receptor. The investigation underscored the significant involvement of Asp223, Gln243, Leu232, Asp251, and Pro254 in the binding of peptides from triple enzymatically hydrolyzed straw mushrooms to T1R1/T1R3. Based on the binding energy and active site analysis, three peptides were selected for synthesis: DFNALPFK (-9.2 kcal/mol), YNEDNGIVK (-8.8 kcal/mol), and VPGGQEIKDR (-8.9 kcal/mol). Notably, 3.2 mmol of VPGGQEIKDR enhanced a 0.05% NaCl solution to the saltiness level of a 0.15% NaCl solution. Also, 0.8 mmol of YNEDNGIVK elevated a 0.05% NaCl solution to the saltiness of a 0.1% NaCl solution.

Background: Functional beverages are ordinary foods with components or ingredients able to provide specific health effects other than purely nutritional effect. Aim: This study aims to formulate a new functional beverage obtained from the recovery of YoAlp® whey, a bovine fermented milk obtained using autochthonous starter cultures, added with Renetta Canada/Golden Delicious-Raspberry (YWL), Renetta Canada-Aronia (YWA) and Ravèntse (YWR) fruit juices to improve the functionality of the beverage. Methods: Microbiological analysis and chemical characterization, by a proteomic approach and spectrophotometric microassay, have been conducted on beverages to investigate the expected shelf-life and potential health promoting effects. Results: The microbiological assessment confirmed the safety of the beverages and the probiotic bacteria vitality over a shelf life of seven days. Biochemical analysis performed highlight the presence of different bioactive peptides (ACE inhibitory and antioxidant), and the betacasomorphin 9 (BCM-9), marker of A2 variant of β-casein typically present in Aosta Valley cattle breeds. Moreover, high amounts of total polyphenols, which concur to the antioxidant activity values observed, have been found. Furthermore, ACE inhibitory activity is well correlated to the bioactive peptides detected. Finally, a consumer test confirmed the YoAlp® whey-based beverages appreciation. Conclusions: The production of these beverages could represent a huge opportunity for Aosta Valley’s farms to increase their income and competitiveness, creating a circular economy by recovering a by-product like whey and following sustainability and healthy trends, which are driving the food sector.

One of the main families of antimicrobial peptides (AMPs) derived from the skin secretions of Hylidae frogs are dermaseptins. Among them, dermaseptin S4 (DS4) is characterized by its broad spectrum of activity against bacteria, protozoa and fungi. This study determined the physicochemical properties of the native peptide DS4(1-28) and its derivatives [DS4(1-28)a and DS4(1-26)a] isolated from the skin of the frog Phyllomedusa sauvagii and examined their antimicrobial properties against two marine pathogenic bacteria (Vibrio harveyi and V. anguillarum). The results indicate that DS4(1-26)a has high bacteriicdal activity against the tested strains and low hemolytic activity (> 30 % lysis at the highest tested concentration of 100 µg mL-1) compared to the other two peptides. In addition, all three peptides affected the membrane and cell wall integrity of both pathogenic bacteria, causing leakage of cellular contents, with DS4(1-26)a having the most severe impact. These properties were corroborated by tansmission electron microscopy and by the variation of cations in their binding sites due to the effect of AMPs. These results suggest that DS4 and its derivatives, particularly the truncated and amidated peptide DS4(1-26)a, could potentially be effective in the treatment of infections caused by these marine pathogenic bacteria. Future experiments are required to validate the use of DS4 in vivo in the prevention of fish bacterial diseases.

Membrane processes, such as microfiltration, ultrafiltration, and nanofiltration are increasingly used for various applications in both upstream and downstream processing. Membrane-based processes play a critical role in the field of separation/purification of biotechnological products, including protein production/purification. The possibility of using membranes to separate peptides from a chicken byproduct hydrolysate and the effect of the performed downstream processing on the DPP-IV inhibitory activity of MDCR (mechanical deboning chicken residue) has been investigated. The chicken byproduct hydrolysate was prepared by enzymatic hydrolysis followed by MF, UF, NF, and RO separation. The LC-OCD analysis confirmed that NF and RO would retain the bioactive peptides in the concentrate in comparison to MF and UF. Bioactivity was correlated with molecular weight distribution profiles and average molecular weights. Permeates after ultrafiltration showed an IC50 value of 0.75 mg/mL, comparable to other potent DPP-IV inhibitors derived from various food sources, and significantly more potent compared to the microfiltration sample, which showed an IC50 value of 1.04 mg/mL. The average molecular weight of the permeates calculated from the SEC chromatograms was 883 g/mol for UF and 1437 g/mol for MF. Of the four membranes studied, the UF membrane showed the best separation properties with respect to maximizing the yield and up-concentration of the bioactive peptides. Overall, UF was demonstrated to be a feasible technology for the removal of the undesired high molecular weight substances and up-concentration of small molecular weight bioactive peptides from chicken byproduct hydrolysate.

Coronaviruses are highly transmissible and pathogenic viruses for humans and animals. The vast quantity of information collected about SARS-CoV-2 during the pandemic helped to unveil details on the mechanisms behind the infection, which are still largely elusive. Recent research demonstrated that different class I/II human leukocyte antigen (HLA) alleles might define an individual susceptibility to SARS-CoV-2 spreading, contributing to the differences in the distribution of the infection through different populations; additional studies suggested that the homolog of the HLA in cats, the Feline Leukocyte Antigen (FLA), plays a pivotal role in the transmission of viruses. With these premises, this study aimed to exploit a bioinformatic approach for the prediction of the transmissibility potential of two distinct Feline Coronaviruses (FCoVs) in domestic cats (Feline enteric Coronavirus, FeCV and Feline Infectious Peritonitis Virus, FIPV) using SARS-CoV-2 as the reference model. We performed an epitope mapping of nonapeptides deriving from SARS-CoV-2, FeCV and FIPV glycoproteins and predicted their affinities for different alleles included in the three main loci in class I FLAs (E, H and K). The predicted complexes with the most promising affinities were then subjected to molecular docking and molecular dynamics simulations to provide insights into the stability and binding energies in the cleft. Results showed the FLA proteins encoded by alleles in FLA-I H (H*00501 and H*00401) and E (E*01001 and E*07001) loci are largely responsive to several epitopes deriving from replicase and spike proteins of the analyzed coronaviruses. The analysis of the most affine epitope sequences resulting from the prediction can stimulate the development of anti-FCoV immunomodulatory strategies based on peptide drugs.

Human Ribonuclease (RNase) 6 is a monocyte and macrophage-derived protein with potent an-timicrobial activity toward uropathogenic bacteria. The RNASE6 gene is heterogeneous in hu-mans due to the presence of single nucleotide polymorphisms (SNPs). RNASE6 rs1045922 is the most common non-synonymous SNP, resulting in a G to A substitution that determines an ar-ginine (R) to glutamine (Q) transversion at position 66 in the protein sequence. By structural analysis we observed that R66Q substitution significantly reduces the positive electrostatic charge at the protein surface. Here, we generated both recombinant RNase 6 -R66 and -Q66 protein variants and determined their antimicrobial activity toward uropathogenic Escherichia coli (UPEC), the most common cause of UTI. We found that the R66 variant, encoded by the major SNP rs1045922 allele, exhibited superior bactericidal activity in comparison to the Q66 variant. The higher bactericidal activity of R66 variant correlated with an increase in the protein lipopolysac-charide binding and bacterial agglutination abilities, while retaining the same enzymatic effi-ciency. These findings encourage further work to evaluate RNASE6 SNP distribution and its impact in UTI susceptibility.

The enormous influence in terms of bioactivity, affinity, and selectivity represented by the replacement of (L)-2,6-dimethyl tyrosine (Dmt) instead of Phenylalanine (Phe) into Nociceptin/orphanin (N/OFQ) neuropeptide analogues, has been well documented in literature. More recently, the non-natural amino acid (L)-2-methyl tyrosine (Mmt), with steric hindrance among Tyr and Dmt, has been studied because of the modulation of steric effects in opioid peptide chains. Here we report a new synthetic strategy to obtain Mmt based on the well-known Pd-catalyzed ortho-C(sp2)–H activation approach, since there is a paucity of other synthetic routes in literature, to achieve it. The aim of this work was to force only the mono ortho-methylation process over the double ortho-methylation one. In this regard we are pleased to report that the introduction of the dibenzylamine moiety on Tyr aromatic nucleus is a convenient and traceless solution to achieve such a goal. Interestingly, our method provided the aimed Mmt either as N-Boc or N-Fmoc derivatives ready to be inserted into peptide chains through solid phase peptide synthesis (SPPS). Importantly, the introduction of Mmt in place of Phe1 in the sequence of N/OFQ(1-13)-NH2 was very well tolerated in terms of pharmacological profile and bioactivity.

Background: Fermented milks are a source of bioactive peptides with different potential benefits on human health (mainly antioxidant and antihypertensive effects) and may be considered as functional foods. Furthermore, those made with sheep milk have higher nutritional value and higher concentrations of proteins, fats, minerals, and vitamins, if compared to milk of other species. Objectives: Aim of this study was to perform a biochemical characterization and a comparison between sheep fermented milk (SFM) made with commercial starter cultures and sheep milk YoAlp®, a fermented milk obtained using local strains of lactic acid bacteria (LABs) (Streptococcus thermophilus and Lactobacillus delbrueckii) which have been isolated during years in Aosta Valley mountain dairy cattle farm. Methods: Sheep milk and fermented milk (Sarda and Lacaune breeds) have been collected and immediately analyzed. Biochemical characterization, by a proteomic approach, GC/MS and microtiter plate assay methods, have been conducted to evaluate their peptide, fatty acid and aromatic profile, and to assess potential health promoting effects. Results: The comparison between SFM and YoAlp® peptide profile shows a higher number of peptides using autochthonous starter cultures (52) than commercial starter cultures (35). Among these peptides 20,78% and 29,87%, respectively, are supposed to be potentially bioactive (DPP - dipeptidyl peptidase-IV - inhibitor, ACE - angiotensin converting enzyme – inhibitor and antioxidant). In both products, the fatty acids profile was similar to that of origin sheep milk; concerning aromatic profile, YoAlp® shows yogurt typical aromatic assets, similar to the commercial one. As far as bioactivity is concerned, ACE inhibitor activity is high for both samples. Similar values, as expected by peptide profile analysis, have been obtained using commercial and autochthonous starters. Even in the case of antioxidant capacity, peptide profile bioactivity prediction has been confirmed by the assay showing a DPPH inhibition higher for SFM than for YoAlp®, but this difference is not statistically significative. Conclusions: Local strains of lactic acid bacteria from Aosta Valley seems to work as well as the commercial, preserving biodiversity and typicality. However, further analyses are needed to identify peptides generated by autochthonous LABs in order to understand microbial proteolytic activities and to investigate gastric digestion resistance of bioactive peptides which can have positive effects on human health.

Celiac disease is an autoimmune disease triggered by oral ingestion of gluten, with certain gluten residues resistant to digestive tract enzymes. Within the duodenum, the remaining peptides incite immunogenic responses, including the generation of autoantibodies and inflammation, leading to irreversible damage. Our previous exploration unveiled a glutenase called Bga1903 derived from the Gram-negative bacterium Burkholderia gladioli. The cleavage pattern of Bga1903 indicated its moderate ability to mitigate the toxicity of pro-immunogenic peptides. The crystal structure of Bga1903, along with the identification of subsites within its active site, was determined. To improve its substrate specificity toward prevalent motifs like QPQ within gluten peptides, the active site of Bga1903 underwent site-directed mutagenesis according to structural insights and enzymatic kinetics. Among the double-site mutants, E380Q/S387L exhibits an approximately 38-fold increase in its specificity constant toward the QPQ sequence, favoring glutamines at the P1 and P3 positions compared to the wild type. Not only does the heightened specificity of E380Q/S387L improve the hydrolytic activity against pro-immunogenic peptides, but also holds this version of the enzyme as a promising candidate as an oral therapy enzyme for celiac disease.

Background: We aimed to evaluate whether baseline GLS and NT-proBNP and their changes after cardiac resynchronization therapy (CRT) can predict the long-term clinical outcomes and the echocardiographic-based response to CRT (defined by 15% relative reduction in left ventricular end-systolic volume). Methods: We enrolled 143 patients with stable, ischemic heart failure (HF) undergoing CRT-D implantation. NT-proBNP and echocardiogram were obtained before and 6 months after. The patients were followed-up (median: 58 months) for HF-related deaths and/or HF hospitalizations (primary endpoint) or HF-related deaths (secondary endpoint) Results: 84 patients achieved the primary and 53 the secondary endpoint, while 104 patients were considered as CRT-responders and 39 as non-responders. At baseline, event-free patients had higher absolute GLS values (p<0.001) and lower NT-proBNP serum levels (p<0001) than those achieving primary endpoint. A similar pattern was observed in favor of CRT-responders vs non-responders. In Cox regression analysis, lower baseline absolute GLS value (HR=0.77;95%CI, 0.51-1.91; p=0.002), higher baseline NT-proBNP levels (HR=1.55;95%CI, 1.43-2.01;p=0.002) and diabetes (HR=1.27;95%CI, 1.12-1.98;p=0.003) were associated with lower incidence of primary endpoint. Conclusions: In HF patients undergoing CRT-D, baseline GLS and NT-proBNP concentrations may serve as prognostic factors, while they may predict the echocardiographic-based response to CRT.

Relative to several model bacteria, the ethanologenic bacterium Zymomonas mobilis is shown here to have an elevated resistance to exogenous antimicrobial peptides (AMPs) – both, with regard to peptide bulk concentration in the medium, and the numbers of peptide molecules per cell. By monitoring integration of the AMPs in the bacterial cell membrane and observing the resulting effect on membrane energy-coupling, it is concluded that the membranotropic effects of the tested AMPs in Z. mobilis and in Escherichia coli are comparable. The advantage of Z. mobilis over E. coli apparently results from its uncoupled mode of energy metabolism that, in contrast to E. coli, does not rely on oxidative phosphorylation, and hence, is less vulnerable to disruption of its energy-coupling membrane by AMPs. It is concluded that the high resistance to antimicrobial peptides (AMPs) observed in Z. mobilis not only proves crucial for its survival in its natural environment but also offers a promising platform for AMP production and sheds light on potential strategies for novel resistance development in clinical settings.

Abstract Octreotide is the first synthetic peptide hormone, consisted of eight amino acids, that mimics the activity of somatostatin, a natural hormone in the body. During the past decades, advanced instrumentation and crystallographic software established X-ray Powder Diffraction (XRPD) as a valuable tool for extracting structural information of biological macromolecules. The latter was demonstrated by the successful structural determination of octreotide at a remarkably high d-spacing resolution (1.87 Å) (PDB code: 6vc1). This study focuses on the response of octreotide to different humidity levels and temperatures, with a particular focus on the stability of the polycrystalline sample. XRPD measurements were accomplished employing an Anton Paar MHC-trans humidity-temperature chamber installed within a laboratory X’Pert Pro diffractometer (Malvern Panalytical). The chamber is employed to control and maintain precise humidity and temperature levels of samples during XRPD data collection. Pawley analysis of the collected data sets revealed that the octreotide polycrystalline sample is remarkably stable and no structural transitions were observed. The compound retains its orthorhombic symmetry (space group: P212121, a = 18.57744(4) Å, b = 30.17338(6) Å, c = 39.70590(9) Å, d~ 2.35 Å). However, a characteristic structural evolution in terms of lattice parameters and volume of the unit-cell is reported mainly upon controlled relative humidity variation. In addition, an improvement of signal-to-noise ratio in the XRPD data under a cycle of dehydration/rehydration is reported. These results underline the importance of considering the impact of environmental factors, as humidity and temperature, in the context of structure-based drug design, thereby contributing to the development of more effective and stable pharmaceutical products.

Background/Aim: Stool gluten immunogenic peptides (GIP) determination is now considered a valuable tool for detecting dietary lapses in treated celiac disease (CeD) patients. Our study aims to explore the diagnostic performance of a qualitative lateral flow immunoassay point-of-care test (LFIA/PoCT) compared with a qualitative enzyme-linked immunosorbent assay (ELISA) for detection of stool GIP. Methods: The study is a post hoc analysis of stool samples collected in the real-life conditions from a cohort of gluten-free diet-treated CeD patients. Stool GIP was measured in µg/g of stool using an ELISA kit (iVYLISA GIP S®, Biomedal SL). For the qualitative evaluation of stool GIP, a LFIA/PoCT test (GlutenDetect®; Biomedal S.L) was employed, which reported results as positive or negative. The LFIA/PoCT performance was evaluated against ELISA, considered as the gold standard. GIP concentrations

The valorization of aquaculture/fisheries processing by-products, as well as unavoidable/unwanted catches and discards in Greece is currently an underutilized activity despite the fact that there are several best practices in Northern Europe and overseas. One of the main challenges is to determine whether the available quantities for processing are sufficient to warrant valorization of discards and fish side streams. This is the first attempt to systematically record and analyze the available quantities of fish by-products and discards in Greece in a spatial and temporal way in an effort to create a national exploitation Master Plan for the valorization of this unavoidable and unwanted biomass. A thorough survey conducted within the VIOAXIOPIO project unveiled a substantial biomass of around 19,000 tonnes annually that could be harnessed for valorization. Furthermore, the production of various High Added Value Biomolecules (HAVB) was investigated, and experimental trials were conducted to assess the potential yields and the collected data were used to formulate four valorization scenarios.

The antimicrobial peptide LRGG (LLRLLRRGGRRLLRLL-NH2) was designed and chemically synthesized in a study conducted by Jia et al. Gram-negative bacteria were found to be sensitive to LRGG and exhibited a high therapeutic index. Genetic engineering methods were used to create the prokaryotic fusion expression vector pQE-GFP-LRGG, and the resulting corresponding fusion protein GFP-LRGG was subsequently expressed and purified. The precursor GFP was then removed by TEV proteolysis, and pure LRGG was obtained after another round of purification and endotoxin removal. The prokaryotic-expressed antimicrobial peptide LRGG displays a broad-spectrum antibacterial effect on gram-negative bacteria and can eliminate 99.99% of E. coli within 100 minutes at the minimal MIC concentration. Compared to the chemically synthesized LRGG, the prokaryotic-expressed LRGG exhibits similar temperature, pH, salt ion, serum stability, and cell selectivity. Furthermore, prokaryotic-expressed LRGG showed excellent therapeutic effects in both the infection model of cell selectivity and no embryotoxicity in a Galleria mellonella infection model. The mechanism by which LRGG causes bacterial death was found to be disruption of Gram-negative cell membrane.

Spinal muscular atrophy (SMA) is a severe neuromuscular disorder that is caused by mutations in the survival motor neuron 1 (SMN1) gene, hindering the production of functional survival motor neuron (SMN) proteins. Antisense oligonucleotides (ASOs), a versatile DNA-like drug, are adept at binding to target RNA to prevent translation or promote alternative splicing. Nusinersen is an FDA-approved ASO for the treatment of SMA. It can effectively promote alternative splicing in SMN2, an analog of SMN1, to produce a greater amount of full length SMN protein, to compensate for the loss of functional protein translated from SMN1. Despite its efficacy in ameliorating SMA symptoms, the cellular uptake of these ASOs is suboptimal and their inability to penetrate the CNS necessitates invasive lumbar punctures. Cell-penetrating peptides (CPPs), that can be conjugated to ASOs, represent a promising approach to improve the efficiency of these treatments for SMA and have the potential to transverse the blood-brain barrier to circumvent the need for intrusive intrathecal injections and their associated adverse effects. This review provides a comprehensive analysis of ASO therapy, their application for the treatment of SMA, and the encouraging potential of CPPs as delivery systems to improve ASO uptake and overall efficiency.

The study of biologically active substances from natural sources shows the prospect of obtaining a new type of antimicrobial agents, highly effective against pathogenic microorganisms and non-toxic to humans. Our study reveals for the first time that Cornu aspersum mucus has the potential to act as a source of antibacterial agents against bacterial pathogens such as Bacillus cereus 1085, Propionibacterium acnes 1897, Salmonella enterica 8691, Enterococcus faecalis 3915, and Enterococcus faecium 8754. Both mucus fractions with MW<20 kDa and MW>20 kDa showed antimicrobial activity and antioxidant properties that’s why they can be turned into an alternative agent to expensive synthetic antibacterial compounds. Using de novo sequencing 16 novel peptides with potential antibacterial activity were identified by in a fraction with MW<20 kDa. The results of electrophoretic and proteomic analysis of mucus fraction with MW >20 kDa presented proteins with potential antibacterial activity highly homologous to hemocyanins, mucus protein Aspernin, lectins, L-amino acid oxidase-like protein, and mucins (mucin-5AC, mucin-5B, mucin-2 and mucin-17). Thanks to the synergistic action of the bioactive components, the mucus fraction with MW > 20 kDa in low concentrations per 8–2 µg/mL showed promising antimicrobial activity against the tested bacteria, comparable to Vancomycin and without unwanted cytotoxic effects against non-target cells. Additionally, C. aspersum mucus fractions were found to have a positive effect on eukaryotic organisms by reducing the levels of intracellular oxidative damage and increasing the antioxidant capacity of the cell. These findings could serve as a basis for the development of a potent non-cytotoxic antibacterial agent to replace conventional antibiotics and avoid the development of antibiotic resistance.

Antimicrobial peptides (AMPs) are promising tools for combating microbial resistance. However, their therapeutic potential is hindered by two intrinsic drawbacks – low target affinity and poor in vivo stability. Macrocyclization, a process that improves the pharmacological properties and bioactivity of peptides, can address these limitations. As a result, macrocyclic peptides represent attractive drug candidates. Moreover, many drugs are macrocycles that originated from natural product scaffolds, suggesting that nature offers solutions to the challenges faced by AMPs. In this review, we explore natural cyclic peptides from the DBAASP database. DBAASP is a comprehensive repository of data on antimicrobial/cytotoxic activities and structures of peptides. We analyze the data on small (≤25 AA) ribosomal and non-ribosomal cyclic peptides from DBAASP according to their amino acid composition, bonds used for cyclization, targets they act on, and mechanisms of action. This analysis will enhance our understanding of the small cyclic peptides that nature has provided to defend living organisms.

Candida auris is considered an emerging Candida species that has rapidly spread all over the world. The evidence of its origin and emerging resistance is still unclear. The severe infection by this species causes significant mortality and morbidity among the elderly and immune compressed individuals. Development of drug resistance is the major factor associated with therapeutic failure of existing antifungal agents. Previous studies addressed the antifungal resistance profile and drug discovery for C. auris. However, comprehensive coverage of these information in a single investigation yet to be available. In this review, we have mainly focused on recent development in therapeutic strategy against C. auris. Based on the available information, several differential approaches were discussed, including existing antifungal drugs, chemical compounds, essential oils, natural products, antifungal peptides, immunotherapy, antimicrobial photodynamic therapy, drug repurposing, and drug delivery systems. Among them, chemical medications, natural products, and antifungal peptides are the prime contributors. However, a limited number of resources are available to prove the efficiency of these potential therapies in clinical usage. Hence, we hope that the data gathered in this review can encourage in vivo studies and clinical trials.