Broad-spectrum hybrid antimicrobial peptides derived from PMAP-23 with potential LPS binding ability

Association of idealized amphiphiles and protease inhibitors: Conferring antimicrobial peptides with stable antibacterial activity under physiological conditions to combat multidrug-resistant bacteria

AIMS

The unstable antimicrobial activity of antimicrobial peptides (AMPs) under physiological conditions (especially the degradation instigated proteases) seems to be a persistent impediment for their successful implementation in clinical trials. Consequently, our objective was to devise AMP engineering frameworks that could sustain robust antibacterial efficacy within physiological environments.

METHODS

In this work, we harvested AMPs with stable antimicrobial activity under the physiological barriers through the combination of idealized amphiphiles and trypsin inhibitors.

RESULTS

We screened and identified the lead peptides IK3-A and IK3-S, which showed potent activity against Gram-negative bacteria, including multidrug-resistant (MDR) bacteria, and exhibited promising biocompatibility with mammalian cells. Remarkably, IK3-A and IK3-S maintained sustained antibacterial potency under physiological salts, serum, and protease conditions. Furthermore, both IK3-A and IK3-S kill Gram-negative bacteria by attacking the bacterial cell membrane and inducing oxidative damage (at high concentrations). Crucially, IK3-A and IK3-S have optimal safety and efficacy in mice.

CONCLUSIONS

This is the first work to compare the effects of different trypsin inhibitors on the resistance of AMPs to protease hydrolysis on the same sequence platform. In conclusion, these findings provide guidance for the molecular design of AMPs with stable antibacterial activity under physiological conditions and facilitates the process of clinical translation of AMPs as antimicrobial biomaterials against MDR bacteria. Moreover, this may stimulate a more general interest in protease inhibitors as molecular scaffolds in the creation of highly stable peptide-based biomaterials.

Dendritic Antifungal Peptides as Potent Agents against Drug-Resistant Candida albicans and Biofilm

Candida albicans infection is a major public health problem, exacerbated by the emergence of drug-resistant fungi with the widespread use of antifungal drugs. Therefore, the development of novel antifungal drugs for drug-resistant C. albicans infections is crucial. We constructed a series of dendritic antifungal peptides (AFPs) with different chain lengths of fatty acids as hydrophobic ends and 2 or 3 protease-stable repeats (Arg-Pro) as dendritic peptide branches. Among them, C4-3RP exhibited excellent antidrug-resistant fungal and biofilm activity (GMall = 5.04 μM) and was nontoxic. Furthermore, C4-3RP demonstrated high protease stability and salt ion tolerance, making it highly effective in murine skin infection mediated by C. albicans. In addition, C4-3RP uses multiple mechanisms of action to achieve excellent antifungal effects. In conclusion, the construction of dendritic peptides holds substantial potential in the treatment of fungal infections and provides a broader perspective on the design of peptide-based antifungal drugs.

Combating Antibiotic-Resistant Bacterial Infection Using Coassembled Dimeric Antimicrobial Peptide-Based Nanofibers

The emergence of multidrug-resistant (MDR) pathogens, coupled with the limited effectiveness of existing antibiotics in eradicating biofilms, presents a significant threat to global health care. This critical situation underscores the urgent need for the discovery and development of antimicrobial agents. Recently, peptide-derived antimicrobial nanomaterials have shown promise in combating such infections. Amino acid noncovalent forces, notably π-π stacking and electrostatic interactions, remain underutilized for guiding the coassembly of peptides into bacteriostatic nanomaterials. Thus, we constructed a dimeric nanopeptide system using the disulfide bonds of cysteine. The self-assembly of dimeric peptides into nanofibers was realized by the interaction of π-π aromatic amino acids (Trp, Phe, and Pyr) and the electrostatic attraction between oppositely charged amino acids (Asp and Arg). The optimal dimeric peptide 2D2W exhibits potent antibacterial activity against resistant bacteria and is nontoxic. Mechanistically, 2D2W penetrated the outer membrane after electrostatic adsorption, resulting in plasma membrane depolarization, homeostatic disruption, and ultimately bacterial death. In a mouse model of peritonitis, 2D2W demonstrated efficacy in the in vivo treatment of bacterial infections. In conclusion, the design of dimeric nanopeptides co-driven by intermolecular forces provides a promising avenue for the development of high-performance antimicrobial nanomaterials. These advances may also facilitate the application and advancement of peptide-based bacteriostatic agents in clinical practice.

Positive Charge-Concentrated Dimeric Lipopeptides with Enhanced Protease Resistance: A Potential Solution for Systemic Bacterial Infections

Antimicrobial peptides (AMPs) show potential as antibiotic alternatives for bacterial infections; nevertheless, the susceptibility to proteases limits their broader utilization. This study developed engineered lipopeptides using antienzymolysis modifications and cysteine (Cys)-dimerization strategy. As the key parameters for the functioning of AMPs, hydrophobicity and positive charges were concentrated within the peptide sequence by adjusting the intermolecular disulfide bond placement to study their distribution effects. Their centralization in the sequence induces a differential propensity of engineered lipopeptides toward bacterial membranes. Positive charge-concentrated dimeric lipopeptide (C-C10)C-C displayed strong resistance to various proteases, and demonstrated excellent stability and activity in vitro, effectively eliminating systemic bacterial infections in mice without eliciting in vivo toxicity. The bactericidal effects of (C-C10)C-C were achieved through a synergistic mechanism involving membrane cleavage and the inhibition of energy metabolism. In summary, these advances offered valuable insights into enhancing the protease resistance of AMPs and the potential for modifying peptide-based biomaterials through Cys-dimerization.

Novel multidomain peptide self-assembly biomaterials based on bola structure and terminal anchoring: Nanotechnology meets antimicrobial therapy

To ameliorate the diminished antimicrobial efficiency and physiological stability associated with monomeric antimicrobial peptides (AMPs) molecules, future research will focus on the artificial design of self-assembling peptides to replace monomeric entities, aiming to combat the antibiotic resistance crisis caused by microbial infections. In this study, the "bola" structure was used as the foundational architecture driving molecular self-assembly, with hydrophobic amino acids at the termini to anchor and finely adjust the sequence, thereby organizing a range of novel multidomain peptides (MDPs) templates into an ABA block motif. The results indicate that FW2 (GMSI = 53.94) exhibits the highest selectivity index among all MDPs and can form spherical micelles in an aqueous medium without the addition of any exogenous additives. FW2 exhibited high stability in vitro in the presence of physiological salt ions, serum, and various pH conditions. It exhibited excellent biocompatibility and efficacy both in vivo and in vitro. Furthermore, FW2 strongly interacts with the lipid membrane and employs various synergistic mechanisms, such as reactive oxygen species (ROS) accumulation, collectively driving cellular apoptosis. This study demonstrates a straightforward strategy for designing self-assembling peptides and promotes the advancement of peptide-based biomaterials integration progress with nanotechnology.

Optimizing therapeutic efficacy of antifungal peptides via strategic terminal amino acid modification

INTRODUCTION

Antifungal peptides (AFPs) have the potential to treat antifungal-resistant infections; however, their structure-function relationship remains unknown, hindering their rapid development. Therefore, it is imperative to investigate and clarify the structure-function relationships of AFPs.

OBJECTIVES

This study aimed to investigate the impact of end-tagging single hydrophobic amino acids and capping the N-terminus with glycine (Gly) on the antifungal activity of peptide W4.

METHODS

The antifungal efficacy of the engineered peptides was initially assessed by determining the minimum inhibitory concentration (MIC) /minimal fungicidal concentration (MFC), killing kinetics, and drug resistance induction, in addition to evaluating the biocompatibility and stability. Subsequently, the antifungal mechanism was investigated using fluorescence labeling, electron microscopy, reactive oxygen species (ROS) detection, and measurement of mitochondrial membrane potential and apoptosis. The impact of the engineered peptides on Candida albicans (C. albicans) biofilm and their potential application in the scratch keratomycosis model were investigated.

RESULTS

The antifungal activity of W4 was significantly enhanced by capping Gly at the N-terminus, resulting in a decrease in average activity from 11.86 μM to 6.25 μM (GW4) and an increase in TI values by 1.9-fold (TIGW4 = 40.99). Mechanistically, GW4 exerted its antifungal effect by disrupting the cellular membrane structure in C. albicans, forming pores and subsequent leakage of intracellular contents. Concurrently, it facilitated intracellular ROS accumulation while decreasing the mitochondrial membrane potential. Additionally, GW4 demonstrated an excellent ability to inhibit and eliminate biofilms of C. albicans. Notably, GW4 demonstrated significant therapeutic potential in a C. albicans-associated keratitis model.

CONCLUSION

Capping Gly at the N-terminus increased residue length while significantly enhancing the helical propensity of W4, thereby augmenting its antifungal activity. Our exploratory study demonstrated the potential strategies and avenues for optimizing the structure-function relationships of AFPs and developing highly effective antifungal drugs.

Biomimetic Peptide Nanonets: Exploiting Bacterial Entrapment and Macrophage Rerousing for Combatting Infections

The alarming rise in global antimicrobial resistance underscores the urgent need for effective antibacterial drugs. Drawing inspiration from the bacterial-entrapment mechanism of human defensin 6, we have fabricated biomimetic peptide nanonets composed of multiple functional fragments for bacterial eradication. These biomimetic peptide nanonets are designed to address antimicrobial resistance challenges through a dual-approach strategy. First, the resulting nanofibrous networks trap bacteria and subsequently kill them by loosening the membrane structure, dissipating proton motive force, and causing multiple metabolic perturbations. Second, these trapped bacterial clusters reactivate macrophages to scavenge bacteria through enhanced chemotaxis and phagocytosis via the PI3K-AKT signaling pathway and ECM-receptor interaction. In vivo results have proven that treatment with biomimetic peptide nanonets can alleviate systemic bacterial infections without causing noticeable systemic toxicity. As anticipated, the proposed strategy can address stubborn infections by entrapping bacteria and awakening antibacterial immune responses. This approach might serve as a guide for the design of bioinspired materials for future clinical applications.

Activity and mechanism of action of antimicrobial peptide ACPs against Candida albicans

AIMS

Candida albicans is the most prevalent pathogenic fungus, exhibiting escalating multidrug resistance (MDR). Antimicrobial peptides (AMPs) represent promising candidates for addressing this issue. In this research, five antimicrobial peptides, ACP1 to ACP5 which named ACPs were studied as alternative fungicidal molecules.

MAIN METHODS

CD assay was used to analyze the 2D structures, Absorbance method was used to test the antimicrobial activity, haemolytic activity, time-kill kinetics, biofilm inhibition and reduction activity, resistance induction activity and assessment against fluconazole-resistant C. albicans. SEM, TEM, CLSM, flow cytometer and FM were carried out to provide insight into the mechanisms of anti-Candida action.

KEY FINDINGS

ACPs possessed an α-helical structure and strong anti-Candida activities, with minimum inhibitory concentrations (MICs) from 3.9 to 15.6 μg/mL. In addition, ACPs did not produce hemolysis at concentrations lower than 10 or 62 × MIC, indicating their low cytotoxicity. Fungicidal kinetics showed that they completely killed C. albicans within 8 h at 2 to 4 × MIC. Notably, ACPs were highly fungicidal against fluconazole-resistant C. albicans and showed low resistance. In addition, they were effective in inhibiting mycelium and biofilm formation. Fluorescence microscopy revealed that while fluconazole had minimal to no inhibitory effect on biofilm-forming cells, ACPs induced apoptosis in all of them. The research on mechanism of action revealed that ACPs disrupted the cell membranes, with ROS increasing and cellular mitochondrial membrane potential decreasing.

SIGNIFICANCE

ACPs could be promising candidates for combating fluconazole-resistant C. albicans infections.

Antibacterial Hydrogels for Wound Dressing Applications: Current Status, Progress, Challenges, and Trends

Bacterial infection treatment for chronic wounds has posed a major medical threat and challenge. Bacteria at the wounded sites can compete with the immune system and subsequently invade live tissues, leading to more severe tissue damage. Therefore, there is an urgent demand for wound dressings with antibacterial and anti-inflammatory properties. Considering the concept of moist healing, hydrogels with a three-dimensional (3D) network structure are widely used as wound dressings due to their excellent hydrophilicity, water retention properties, and biocompatibility. Developing antibacterial hydrogels for the treatment of infected wounds has been receiving extensive attention recently. This article categorizes antibacterial hydrogels according to their materials and antibacterial modes, and introduces the recent findings and progress regarding their status. More importantly, with the development of emerging technologies, new therapies are utilized to prepare antibacterial hydrogels such as nanoenzymes, photothermal therapy (PTT), photodynamic therapy (PDT), metal-organic frameworks (MOFs), and other external stimuli-responsive methods. Therefore, this review also examines their progress, challenges, and future trends as wound dressings. In the following studies, there will still be a focus on antibacterial hydrogels that have a high performance, multi-functions, and intelligence, especially biocompatibility, a high and long-lasting antibacterial property, responsiveness, and on-demand therapeutic ability.

Design of Proteolytic-Resistant Antifungal Peptides by Utilizing Minimum d-Amino Acid Ratios

Antifungal peptides are an appealing alternative to standard antifungal medicines due to their unique mechanism of action and low-level resistance. However, their susceptibility to protease degradation keeps hindering their future development. Herein, a library was established to design peptides with protease resistance and high antifungal activity. The peptides were incorporated with minimal D-amino acids to further improve the protease stability. The most active peptide, IR3, demonstrated good antifungal activity and low toxicity, and its molecular integrity was maintained after protease hydrolysis for 8 h at 2 mg/mL. Furthermore, IR3 could permeate the fungal cell wall, disrupt the cell membrane, produce reactive oxygen species, and induce apoptosis in fungal cells. In vivo experiments confirmed that IR3 could effectively treat fungal keratitis. Collectively, these findings suggest that IR3 is a promising antifungal agent and may be beneficial in the design and development of protease-resistant antifungal peptides.

The gain effect of microbial consortia induced by adaptive domestication for efficient conversion of Chinese cabbage waste by anaerobic fermentation

The resource-based treatment of Chinese cabbage waste by anaerobic fermentation can effectively mitigate air, soil, and groundwater pollution. However, the compatibility between fermentative microorganisms and the environment might be a crucial limiting factor for the resource recycling of Chinese cabbage waste. Therefore, the gain effect of microbial consortia (JMRS, JMRST, JMRSZ, JCCW, JCCWT and JCCWZ) induced by adaptive domestication for efficient conversion of Chinese cabbage waste by anaerobic fermentation were explored in this study. A total of 42 single subsamples with same weights were randomly divided into seven treatments: sterile deionized water (Control); anaerobic fermentation inoculated with JMRS (MRS); anaerobic fermentation inoculated with JMRST (MRST); anaerobic fermentation inoculated with JMRSZ (MRSZ); anaerobic fermentation inoculated with JCCW (CCW); anaerobic fermentation inoculated with JCCWT (CCWT); anaerobic fermentation inoculated with JCCWZ (CCWZ) and samples were taken on days 30 and 60 after anaerobic fermentation. The results exhibited that all the treatments contributed to high levels of lactic acid (178.77-201.79 g/kg dry matter) and low levels of ammonia-N (12.99-21.03 g/kg total nitrogen). Meanwhile, MRSZ enhanced (p < 0.05) acetic acid levels (1.53 g/kg dry matter) and resulted in the lowest yeast counts. Microbiologically, the addition of microbial consortia decreased the linear discriminant analysis (LDA) scores of Massilia and Stenotrophomonas maltophilia. Moreover, MRSZ enriched (p < 0.05) Lactobacillus hilgardii, and decreased (p < 0.05) the abundance of bacteria containing mobile elements and potentially pathogenic bacteria. In conclusion, JMRSZ improved the efficient conversion of Chinese cabbage waste for resource utilization.

Antimicrobial peptides in bone regeneration: mechanism and potential

INTRODUCTION

Antimicrobial peptides (AMPs) are small-molecule peptides with a unique antimicrobial mechanism. Other notable biological activities of AMPs, including anti-inflammatory, angiogenesis, and bone formation effects, have recently received widespread attention. These remarkable bioactivities, combined with the unique antimicrobial mechanism of action of AMPs, have led to their increasingly important role in bone regeneration.

AREAS COVERED

In this review, on the one hand, we aimed to summarize information about the AMPs that are currently used for bone regeneration by reviewing published literature in the PubMed database. On the other hand, we also highlight some AMPs with potential roles in bone regeneration and their possible mechanisms of action.

EXPERT OPINION

The translation of AMPs to the clinic still faces many problems, but their unique antimicrobial mechanisms and other conspicuous biological activities suggest great potential. An in-depth understanding of the structure and mechanism of action of AMPs will help us to subsequently combine AMPs with different carrier systems and perform structural modifications to reduce toxicity and achieve stable release, which may be a key strategy for facilitating the translation of AMPs to the clinic.

Double-Network Hydrogel with Strengthened Mechanical Property for Controllable Release of Antibacterial Peptide

Developing double-network (DN) hydrogels with high mechanical properties and antibacterial efficacy to combat multidrug-resistant bacterial infections and serve as scaffolds for cell culture still remains an ongoing challenge. In this study, an ion-responsive antibacterial peptide (AMP) (C16-WIIIKKK, termed as IK7) was synergistically combined with a photoresponsive gelatin methacryloyl (GelMA) polymer to fabricate a biocompatible DN hydrogel. The GelMA-IK7 DN hydrogel showed enhanced mechanical properties in contrast to the individual IK7 and GelMA hydrogels and demonstrated substantial antibacterial efficacy. Further investigations revealed that the DN hydrogel effectively inhibited bacterial growth by the controlled and sustained release of the IK7 peptide. In addition, the formation of the DN hydrogel was also found to protect AMP IK7 from rapid degradation by proteinase K. Our findings suggested that the developed GelMA-IK7 DN hydrogel holds great potential for next-generation antibacterial hydrogels for three-dimensional cell culture and tissue regeneration.

Heterologous expression of the novel dimeric antimicrobial peptide LIG in Pichia pastoris

The antimicrobial peptide (AMP) LI is a fusion product of antimicrobial peptide LL37 produced by human neutrophils and Indolicidin secreted by bovine neutrophils. LI retained the antimicrobial activity of the parental peptides and showed high cell selectivity. In this study, the flexible linker Gly-Ser-Gly (G-S-G) was used to ligate LI into dimeric LIG, and constructed the Pichia pastoris (P. pastoris) expression vector pPIC9K-6×His-3×FLAG-LIG. The total protein expression of P. pastoris GS115 reached the highest level (189.6 mg/L) after 96 h induction with 3 % methanol at the initial pH value of 7.0. Finally, 5.9 mg/L of recombinant LIG (rLIG) was obtained after enterokinase digestion and purification. The rLIG had high antimicrobial activity and low hemolytic activity. Compared with monomer LI, GSG linked dimeric LIG, which had no significant change in antimicrobial activity and had good salt ions stability. In this study, the dimeric antimicrobial peptide LIG was successfully expressed, which provided a new idea for the expression of AMPs in the P. pastoris expression system, and had important significance for the application of AMPs.

Interaction with lipopolysaccharide is key to efficacy of tryptophan- and arginine-rich α-melanocyte-stimulating hormone analogs against Gram-negative bacteria

Aim: In order to search for novel antibacterial therapeutics against Gram-negative bacteria, the antibacterial efficacies and mechanism of action of tryptophan- and arginine-rich α-melanocyte-stimulating hormone analogs were investigated. Materials & methods: We performed a killing assay to determine their efficacy; fluorescence, microscopic studies were used to understand their mechanism and peptide-lipopolysaccharide interaction. A checkerboard assay was used to find the effective combination of peptide and antibiotics. Results: Ana-peptides displayed good killing activity against Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Their strong interaction with lipopolysaccharide damaged the bacterial membranes and led to their subsequent death. Ana-5, the highest cationic and hydrophobic analog, emerged as the most potent peptide, showing synergistic action with rifampicin and erythromycin. Conclusion: Ana-5 can be presented as an important therapeutic candidate against bacterial infections.

Anti-Proteolytic Peptide R7I Protects the Intestinal Barrier and Alleviates Fatty Acid Malabsorption in Salmonella typhimurium-Infected Mice

With a wide range of hosts, environmental adaptation, and antibiotic resistance, Salmonella typhimurium is one of the most common causes of food poisoning in the world. Infection with Salmonella typhimurium not only results in intestinal inflammation but also damages the intestinal barrier and interferes with the host's ability to absorb nutrients. It is imperative to find alternatives to antibiotics for eradicating bacteria, reducing intestinal damage, and reestablishing nutrient absorption, especially given that antibiotics are currently prohibited. This research aims to understand the protective role of anti-proteolytic peptide R7I on the gut in the setting of Salmonella typhimurium infection and its impact on nutritional absorption, maybe offering an alternative to antibiotics for bacterial killing. The findings demonstrated that R7I reduced the production of inflammatory factors, including IL-6, TNF-α, and L-1β in the jejunum and decreased the expression of genes like TLR4 and NF-κB in the jejunum (p < 0.05). R7I enhanced antioxidant capacity and preserved the antioxidant/pro-oxidant balance in the jejunum (p < 0.05). R7I also normalized intestinal shape and restored tight junction protein expression. Fatty acid binding protein 2 (FABP2) and fatty acid transport protein 4 (FATP4) expression in the jejunum was restored by R7I. In addition, serum-free fatty acids and lipid metabolites were significantly higher in the R7I group than in the control group (p < 0.05). Overall, the anti-enzyme peptide R7I maintained the healthy state of the intestine and alleviated the abnormal fatty acid absorption caused by bacterial infection.

The antimicrobial peptide chensinin-1b alleviates the inflammatory response by targeting the TLR4/NF-κB signaling pathway and inhibits Pseudomonas aeruginosa infection and LPS-mediated sepsis

Excessive inflammatory responses are a major contributor to the high mortality associated with sepsis, a prevalent global complication. Therefore, the potential therapeutic strategy for sepsis involves targeting macrophages and reducing proinflammatory cytokine release. Chensinin-1b, an analog of the natural antimicrobial peptide derived from Rana chensinensis skin secretion, exhibits broad-spectrum antibacterial activity and adopts a random coil conformation in both PBS and membrane solution. By efficiently neutralizing LPS, chensinin-1b holds promise in alleviating LPS-induced inflammatory responses. In this study, we established a mouse septic shock model by exposing mice to multiple-drug-resistant Pseudomonas aeruginosa, as well as an endotoxin-mediated sepsis model induced by LPS. Administering chensinin-1b significantly prolonged the survival of the experimental mice, concurrently mitigating inflammatory responses and reducing organ damage. Additionally, we investigated the anti-inflammatory mechanism of chensinin-1b using a constructed LPS-induced mouse macrophage RAW264.7 inflammatory model. Our findings demonstrated that chensinin-1b effectively mitigated the excessive activation of the TLR4/NF-κB signaling pathway by directly neutralizing extracellular LPS, thus ameliorating the inflammatory response. Moreover, upon blocking the TLR4 signaling pathway, chensinin-1b further reduced the release of proinflammatory cytokines induced by LPS, indicating alternative modes of regulation. Notably, chensinin-1b rapidly entered RAW264.7 cells within 30 min via endocytosis, diffusing into the cytoplasm while retaining its anti-inflammatory properties intracellularly. Although further investigations are warranted to comprehensively elucidate the intracellular anti-inflammatory mechanism of chensinin-1b, our findings substantiate its possession of anti-inflammatory properties both intracellularly and extracellularly. Thus, chensinin-1b emerges as a promising candidate for mitigating excessive inflammatory responses associated with sepsis.

Boosting stability and therapeutic potential of proteolysis-resistant antimicrobial peptides by end-tagging β-naphthylalanine

Recently, much emphasis has been placed on solving the intrinsic defects of antimicrobial peptides (AMPs), especially their susceptibility to protease digestion for the systemic application of antibacterial biomaterials. Although many strategies have increased the protease stability of AMPs, antimicrobial activity was severely compromised, thereby substantially weakening their therapeutic effect. To address this issue, we introduced hydrophobic group modifications at the N-terminus of proteolysis-resistant AMPs D1 (AArIIlrWrFR) through end-tagging with stretches of natural amino acids (W and I), unnatural amino acid (Nal) and fatty acids. Of these peptides, N1 tagged with a Nal at N-terminus showed the highest selectivity index (GM_SI = 19.59), with a 6.73-fold improvement over D1. In addition to potent broad-spectrum antimicrobial activity, N1 also exhibited high antimicrobial stability toward salts, serum and proteases in vitro and ideal biocompatibility and therapeutic efficacy in vivo. Furthermore, N1 killed bacteria through multiple mechanisms, involving disruption of bacterial membranes and inhibition of bacterial energy metabolism. Indeed, appropriate terminal hydrophobicity modification opens up new avenues for developing and applying high-stability peptide-based antibacterial biomaterials. STATEMENT OF SIGNIFICANCE: To improve the potency and stability of proteolysis-resistant antimicrobial peptides (AMPs) without increasing toxicity, we constructed a convenient and tunable platform based on different compositions and lengths of hydrophobic end modifications. By tagging an Nal at the N-terminal, the obtained target compound N1 exhibited strong antimicrobial activity and desirable stability under multifarious environments in vitro (protease, salts and serum), and also showed favorable biocompatibility and therapeutic efficacy in vivo. Notably, N1exerted its bactericidal effect by damaging bacterial cell membranes and inhibiting bacterial energy metabolism in a dual mode. The findings provide a potential method for designing or optimizing proteolysis-resistant AMPs thus promoting the development and application of peptide-based antibacterial biomaterial.