Tissue damage alleviation and mucin inhibition by P5 in a respiratory infection mouse model with multidrug-resistant Acinetobacter baumannii.

Although the discovery of antibiotics has made significant positive contributions to public health and medicine, it now poses a serious threat due to the increasing antibiotic resistance in various bacteria. Carbapenem-resistant and multidrug-resistant (MDR) Acinetobacter baumannii is spreading globally, exacerbating respiratory diseases such as chronic obstructive pulmonary disease and cystic fibrosis. Antimicrobial peptides (AMPs), with broad antibacterial activity, have emerged as promising alternatives for treating MDR A.

Repurposing an antimicrobial peptide for the development of a dual ion channel/molecular receptor-like platform for metal ion detection.

The presence of non-essential metals in the environment as contaminants is prone to cause hazardous health problems following accumulation in the human body and the ensuing toxic effects. This calls for continuous discovery and innovation in the realm of developing easy-to-operate, cheap and sensitive sensors. Herein, we describe the proof of concept approach for designing a molecular receptor-like, chimeric sensor based on the pore-forming peptide alamethicin (Alm), tethered a linker with an ultrashort peptide nucleic acid (PNA) moiety, capable of generating functional ion channel oligomers in planar lipid membranes.

Exploring the Therapeutic Potential of Scorpion-Derived Css54 Peptide Against Candida albicans.

Candida albicans (C. albicans) is one of the most common opportunistic fungi worldwide, which is associated with a high mortality rate. Despite treatment, C.

Correction: Considerable slowdown of short DNA fragment translocation across a protein nanopore using pH-induced generation of enthalpic traps inside the permeation pathway.

Correction for 'Considerable slowdown of short DNA fragment translocation across a protein nanopore using pH-induced generation of enthalpic traps inside the permeation pathway' by Loredana Mereuta , , 2023, , 14754-14763, https://doi.org/10.1039/D3NR03344A.

Considerable slowdown of short DNA fragment translocation across a protein nanopore using pH-induced generation of enthalpic traps inside the permeation pathway.

A pressing challenge in the realm of nanopore-based sensing technologies for nucleic acid characterization has been the cheap and efficient control of analyte translocation. To address this, a plethora of methods were tested, including mutagenesis, molecular motors, enzymes, or the optimization of experimental conditions. Herein, we present a paradigm exploiting the manipulation of electrostatic interactions between 22-mer single-stranded DNAs (22_ssDNA) and low pH-induced charges in the alpha-hemolysin (α-HL) nanopore, to efficiently control the passage of captured molecules.

Synthetic Receptor Based on a Peptide Antibiotic-Functionalized Chimera for Hybridization-Based Polynucleotide Detection.

Nanopores offer highly sensitive, low-cost, and single-molecule sensing capabilities, and the societal impact of this approach is best captured by the advent of nanopore-based DNA detection and sequencing technologies, which extract genomic information without amplification. To address a critical difficulty plaguing such undertakings involving especially protein-based nanopores isolated in lipid bilayers, namely, the formation of a stable, long-lasting single nanopore, we pioneer herein an approach for generating functional nanostructures enabling small single-stranded DNA (ssDNA) detection. We designed a dynamic hybrid construct by appending extramembrane peptide nucleic acid (PNA) segments to the C-terminus of modified ion channel-forming alamethicin monomers.

Lycosin-II Exhibits Antifungal Activity and Inhibits Dual-Species Biofilm by and .

The increase and dissemination of antimicrobial resistance is a global public health issue. To address this, new antimicrobial agents have been developed. Antimicrobial peptides (AMPs) exhibit a wide range of antimicrobial activities against pathogens, including bacteria and fungi.

Therapeutic Potential of Antimicrobial Peptide PN5 against Multidrug-Resistant E. coli and Anti-Inflammatory Activity in a Septic Mouse Model.

Antibiotic-resistant bacteria have become a public health problem. Thus, antimicrobial peptides (AMPs) have been evaluated as substitutes for antibiotics. Herein, we investigated PN5 derived from Pinus densiflora (pine needle).

Cathelicidin-related antimicrobial peptide mediates skeletal muscle degeneration caused by injury and Duchenne muscular dystrophy in mice.

Background: Cathelicidin, an antimicrobial peptide, plays a key role in regulating bacterial killing and innate immunity; however, its role in skeletal muscle function is unknown. We investigated the potential role of cathelicidin in skeletal muscle pathology resulting from acute injury and Duchenne muscular dystrophy (DMD) in mice.

Methods: Expression changes and muscular localization of mouse cathelicidin-related antimicrobial peptide (Cramp) were examined in the skeletal muscle of normal mice treated with chemicals (cardiotoxin and BaCl ) or in dystrophic muscle of DMD mouse models (mdx, mdx/Utrn and mdx/Utrn ).

A Nanopore Sensor for Multiplexed Detection of Short Polynucleotides Based on Length-Variable, Poly-Arginine-Conjugated Peptide Nucleic Acids.

Real-time and easy-to-use detection of nucleic acids is crucial for many applications, including medical diagnostics, genetic screening, forensic science, or monitoring the onset and progression of various diseases. Herein, an exploratory single-molecule approach for multiplexed discrimination among similar-sized single-stranded DNAs (ssDNA) is presented. The underlying strategy combined (i) a method based on length-variable, short arginine (poly-Arg) tags appended to peptide nucleic acid (PNA) probes, designed to hybridize with selected regions from complementary ssDNA targets (cDNA) in solution and (ii) formation and subsequent detection with the α-hemolysin nanopore of (poly-Arg)-PNA-cDNA duplexes containing two overhangs associated with the poly-Arg tail and the non-hybridized segment from ssDNA.

Anti-biofilm and anti-inflammatory effects of Lycosin-II isolated from spiders against multi-drug resistant bacteria.

Currently, multidrug-resistant bacteria are rapidly increasing worldwide because of the misuse or overuse of antibiotics. In particular, few options exist for treating infections caused by long-persisting oxacillin-resistant strains and recently proliferating carbapenem-resistant strains. Therefore, alternative treatments are urgently needed.

PEP27-2, a Potent Antimicrobial Cell-Penetrating Peptide, Reduces Skin Abscess Formation during Infections in Mouse When Used in Combination with Antibiotics.

PEP27, a 27-amino acid (aa) peptide secreted by , is an autolytic peptide that functions as a major virulence factor. To develop a clinically applicable antimicrobial peptide (AMP), we designed PEP27 analogs with Trp substitutions to enhance its antimicrobial activity compared to that of PEP27. Particularly, PEP27-2 showed strong antimicrobial activity against a wide variety of bacteria, including multidrug-resistant (MDR) bacteria.

A phage protein-derived antipathogenic peptide that targets type IV pilus assembly.

Phage-inspired antibacterial discovery is a new approach that recruits phages in search for antibacterials with new molecular targets, in that phages are the biological entities well adapted to hijack host bacterial physiology in favor of their own thrive. We previously observed that phage-mediated twitching motility inhibition was effective to control the acute infections caused by and that the motility inhibition was attributed to the delocalization of PilB, the type IV pilus (TFP) assembly ATPase by binding of the 136-amino acid (aa) phage protein, Tip. Here, we created a series of truncated and point-mutant Tip proteins to identify the critical residues in the Tip bioactivity: N-terminal 80-aa residues were dispensable for the Tip activity; we identified that Asp82, Leu84, and Arg85 are crucial in the Tip function.

Intra-Articular Administration of Cramp into Mouse Knee Joint Exacerbates Experimental Osteoarthritis Progression.

Osteoarthritis (OA) is the most common type of arthritis and is associated with wear and tear, aging, and inflammation. Previous studies revealed that several antimicrobial peptides are up-regulated in the knee synovium of patients with OA or rheumatoid arthritis. Here, we investigated the functional effects of cathelicidin-related antimicrobial peptide (Cramp) on OA pathogenesis.

Non-Receptor-Mediated Lipid Membrane Permeabilization by the SARS-CoV-2 Spike Protein S1 Subunit.

Due to the pressing need to generate specific drugs or vaccines for COVID-19 and management of its outbreak, detailed knowledge regarding the SARS-CoV-2 entry into host cells and timely, cheap, and easy-to-use detection methods are of critical importance for containing the SARS-CoV-2 epidemic. Through electrophysiology and fluorescence spectroscopy experiments, we show that even in the absence of the angiotensin-converting enzyme 2 receptor, the S1 subunit from SARS-CoV-2 spike protein binding to neutral phospholipid membranes leads to their mechanical destabilization and permeabilization. A similar cytotoxic effect of the protein was seen in human lung epithelial cells.

Scorpion-Venom-Derived Antimicrobial Peptide Css54 Exerts Potent Antimicrobial Activity by Disrupting Bacterial Membrane of Zoonotic Bacteria.

Antibiotic resistance is an important issue affecting humans and livestock. Antimicrobial peptides are promising alternatives to antibiotics. In this study, the antimicrobial peptide Css54, isolated from the venom of , was found to exhibit antimicrobial activity against bacteria such as , , , and that cause zoonotic diseases.

Author Correction: Sequence-specific detection of single-stranded DNA with a gold nanoparticle-protein nanopore approach.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Sequence-specific detection of single-stranded DNA with a gold nanoparticle-protein nanopore approach.

Fast, cheap and easy to use nucleic acids detection methods are crucial to mitigate adverse impacts caused by various pathogens, and are essential in forensic investigations, food safety monitoring or evolution of infectious diseases. We report here a method based on the α-hemolysin (α-HL) nanopore, working in conjunction to unmodified citrate anion-coated gold nanoparticles (AuNPs), to detect nanomolar concentrations of short single-stranded DNA sequences (ssDNA). The core idea was to use charge neutral peptide nucleic acids (PNA) as hybridization probe for complementary target ssDNAs, and monitor at the single-particle level the PNA-induced aggregation propensity AuNPs during PNA-DNA duplexes formation, by recording ionic current blockades signature of AuNP-α-HL interactions.

Antifungal and Antibiofilm Activities and the Mechanism of Action of Repeating Lysine-Tryptophan Peptides against .

The rapid increase in the emergence of antifungal-resistant strains is becoming a serious health concern. Because antimicrobial peptides (AMPs) may provide a potential alternative to conventional antifungal agents, we have synthesized a series of peptides with a varying number of lysine and tryptophan repeats (KW-NH). The antifungal activity of these peptides increased with peptide length, but only the longest KW peptide displayed cytotoxicity towards a human keratinocyte cell line.

NF-κB Signaling Pathways in Osteoarthritic Cartilage Destruction.

Osteoarthritis (OA) is a type of joint disease associated with wear and tear, inflammation, and aging. Mechanical stress along with synovial inflammation promotes the degradation of the extracellular matrix in the cartilage, leading to the breakdown of joint cartilage. The nuclear factor-kappaB (NF-κB) transcription factor has long been recognized as a disease-contributing factor and, thus, has become a therapeutic target for OA.

Nonfunctionalized PNAs as Beacons for Nucleic Acid Detection in a Nanopore System.

In this work, single-channel current recordings were used to selectively detect individual ssDNA strands in the vestibule of the α-hemolysin (α-HL) protein nanopore. The sensing mechanism was based on the detection of the intrinsic topological change of target ssDNA molecules after the hybridization with complementary PNA fragments. The readily distinguishable current signatures of PNA-DNA duplexes reversible association with the α-HL's vestibule, in terms of blockade amplitudes and kinetic features, allows specific detection of nucleic acid hybridization.

Antibacterial and anti-biofilm activity, and mechanism of action of pleurocidin against drug resistant Staphylococcus aureus.

The abuse of antibiotics has resulted in the emergence of multi-drug-resistant bacteria. Staphylococcus aureus is a frequent cause of infections, and antibiotic-resistant S. aureus has become a serious problem.

Antibacterial and Antibiofilm Activity and Mode of Action of Magainin 2 against Drug-Resistant Acinetobacter baumannii.

Antimicrobial peptides (AMPs) are promising therapeutic agents for treating antibiotic-resistant bacterial infections. Previous studies showed that magainin 2 (isolated from African clawed fogs ) has antimicrobial activity against gram-positive and gram-negative bacteria. The present study was conducted to investigate the antibacterial activity of magainin 2 against .

Antibacterial activity and mechanism of action of analogues derived from the antimicrobial peptide mBjAMP1 isolated from Branchiostoma japonicum.

Objectives: The worldwide increase in antibiotic-resistant bacteria is a growing threat to public health. Antimicrobial peptides (AMPs) are potentially effective alternatives to conventional antibiotics. We therefore tested analogues of the AMP mBjAMP1 from Branchiostoma japonicum, which we produced by adding and/or replacing amino acids to increase antimicrobial activity against Gram-negative bacteria.

Antimicrobial peptide-loaded gold nanoparticle-DNA aptamer conjugates as highly effective antibacterial therapeutics against Vibrio vulnificus.

Vibrio vulnificus causes fatal infections in humans, and antibiotics are commonly used in treatment regimens against V. vulnificus infection. However, the therapeutic effects of antibiotics are limited by multidrug resistance.