Deletion of All Cysteines in Tachyplesin I Abolishes Hemolytic Activity and Retains Antimicrobial Activity and Lipopolysaccharide Selective Binding†

Magainin 2 (Mag2), which was isolated from the skin of the African clawed frog, is a representative antimicrobial peptide (AMP) that exerts antimicrobial activity via microbial membrane disruption. It has been reported that the helicity and amphipathicity of Mag2 play important roles in its antimicrobial activity. We investigated and recently reported that 17 amino acid residues of Mag2 are required for its antimicrobial activity, and accordingly developed antimicrobial foldamers containing α,α-disubstituted amino acid residues. In this study, we further designed and synthesized a set of Mag2 derivatives bearing the hydrocarbon stapling side chain for helix stabilization. The preferred secondary structures, antimicrobial activities, and cell-membrane disruption activities of the synthesized peptides were evaluated. Our analyses revealed that hydrocarbon stapling strongly stabilized the helical structure of the peptides and enhanced their antimicrobial activity. Moreover, peptide 2 stapling between the first and fifth position from the N-terminus showed higher antimicrobial activity than that of Mag2 against both gram-positive and gram-negative bacteria without exerting significant hemolytic activity. To investigate the modes of action of tested peptides 2 and 8 in antimicrobial and hemolytic activity, electrophysiological measurements were performed.

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Rational design of novel amphipathic antimicrobial peptides focused on the distribution of cationic amino acid residues

MedChemComm ◽

10.1039/c9md00166b ◽

2019 ◽

Vol 10 (6) ◽

pp. 896-900 ◽

Cited By ~ 5

Author(s):

Takashi Misawa ◽

Chihiro Goto ◽

Norihito Shibata ◽

Motoharu Hirano ◽

Yutaka Kikuchi ◽

...

Keyword(s):

Antimicrobial Activity ◽

Amino Acid ◽

Human Cell ◽

Hemolytic Activity ◽

Rational Design ◽

Cell Cytotoxicity ◽

Amino Acid Residues ◽

High Antimicrobial Activity ◽

Cationic Amino Acid ◽

Helical Peptide

Amphipathic helical peptideStripeshowed high antimicrobial activity, low hemolytic activity, and low human cell cytotoxicity.

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The Design of Alapropoginine, a Novel Conjugated Ultrashort Antimicrobial Peptide with Potent Synergistic Antimicrobial Activity in Combination with Conventional Antibiotics

Antibiotics ◽

10.3390/antibiotics10060712 ◽

2021 ◽

Vol 10 (6) ◽

pp. 712

Author(s):

Ali Salama ◽

Ammar Almaaytah ◽

Rula M. Darwish

Keyword(s):

Antimicrobial Activity ◽

Hemolytic Activity ◽

Antimicrobial Agents ◽

Antimicrobial Activities ◽

Resistant Bacteria ◽

Human Red Blood Cells ◽

Drug Resistant Bacteria ◽

Different Strains ◽

Conventional Antibiotics

(1) Background: Antimicrobial resistance represents an urgent health dilemma facing the global human population. The development of novel antimicrobial agents is needed to face the rising number of resistant bacteria. Ultrashort antimicrobial peptides (USAMPs) are considered promising antimicrobial agents that meet the required criteria of novel antimicrobial drug development. (2) Methods: Alapropoginine was rationally designed by incorporating arginine (R), biphenylalanine (B), and naproxen to create an ultrashort hexapeptide. The antimicrobial activity of alapropoginine was evaluated against different strains of bacteria. The hemolytic activity of alapropoginine was also investigated against human erythrocytes. Finally, synergistic studies with antibiotics were performed using the checkerboard technique and the determination of the fractional inhibitory index. (3) Results: Alapropoginine displayed potent antimicrobial activities against reference and multi-drug-resistant bacteria with MIC values of as low as 28.6 µg/mL against methicillin-resistant S. aureus. Alapropoginine caused negligible toxicity toward human red blood cells. Moreover, the synergistic studies showed improved activities for the combined conventional antibiotics with a huge reduction in their antimicrobial concentrations. (4) Conclusions: The present study indicates that alapropoginine exhibits promising antimicrobial activity against reference and resistant strains of bacteria with negligible hemolytic activity. Additionally, the peptide displays synergistic or additive effects when combined with several antibiotics.

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Investigation of a novel artificial antimicrobial peptide by fluorescence correlation spectroscopy: An amphipathic cationic pattern is sufficient for selective binding to bacterial type membranes and antimicrobial activity

Biochimica et Biophysica Acta (BBA) - Biomembranes ◽

10.1016/j.bbamem.2005.08.005 ◽

2005 ◽

Vol 1716 (1) ◽

pp. 29-39 ◽

Cited By ~ 13

Author(s):

Lanlan Yu ◽

Jeak Ling Ding ◽

Bow Ho ◽

Thorsten Wohland

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Peptide ◽

Fluorescence Correlation Spectroscopy ◽

Correlation Spectroscopy ◽

Selective Binding ◽

Fluorescence Correlation ◽

Bacterial Type

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In vitro evaluation of antimicrobial activity and measuring its antigenic specific immune response in mice model studies: Allium cepa

Research Journal of Pharmacy and Technology ◽

10.52711/0974-360x.2021.00451 ◽

2021 ◽

pp. 2563-2568

Author(s):

Amit Gupta ◽

Karishma Ghosh ◽

Dakshita Snud Sharma ◽

Shubham Tyagi

Keyword(s):

Cell Proliferation ◽

Antimicrobial Activity ◽

T Cell ◽

Allium Cepa ◽

Aqueous Extract ◽

Hemolytic Activity ◽

Cell Culture Supernatant ◽

T Cell Proliferation ◽

Mice Model ◽

Model Studies

Allium cepa (onion; Liliaceae family), herbaceous annual plant and reported Sulphur based amino acids with many minerals including vitamins. Inspite of various medicinal uses of this plant as food and also showed various beneficial effects. The antimicrobial activity of aqueous extract from Allium cepa (onion bulb) was evaluated against bacterial strains using disc diffusion method. In contrast, inflammatory response or inhibition of T cell antigenic response was evaluated using typhoid vaccine and swine flu vaccine in Swiss mice. These studies were conducted according to ethical guidelines and determining T cell proliferation including estimation of cytokines from cell culture supernatant and also measuring its hemolytic activity. The results showed that aqueous extract show the highest inhibition rate against Pseudomonas aeruginosa and Salmonella enteritidis. In mice model studies, aqueous extract at higher doses showed inhibition in antigen specific T cell proliferation and also declining in the level of IFN-gamma production but enhancement in IL-4 production. In addition, aqueous extract at higher concentration does not showed any hemolytic activity. Overall, this study provides evidence for the presence of secondary metabolites in aqueous extract that probably interferes with bacterial growth (antimicrobial) and also declining in antigenic specific proliferation (i.e. anti-inflammatory) which would prevent and inhibit initiation and progression of many diseases.

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Effects of Dimerization on the Structure and Biological Activity of Antimicrobial Peptide Ctx-Ha

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.06262-11 ◽

2012 ◽

Vol 56 (6) ◽

pp. 3004-3010 ◽

Cited By ~ 32

Author(s):

E. N. Lorenzón ◽

G. F. Cespedes ◽

E. F. Vicente ◽

L. G. Nogueira ◽

T. M. Bauab ◽

...

Keyword(s):

Antimicrobial Activity ◽

Biological Activity ◽

Antimicrobial Peptide ◽

Hemolytic Activity ◽

Pore Diameter ◽

Solid Phase ◽

Biological Activities ◽

Solid Phase Peptide Synthesis ◽

Activity Assay ◽

Growth Of Bacteria

ABSTRACTIt is well known that cationic antimicrobial peptides (cAMPs) are potential microbicidal agents for the increasing problem of antimicrobial resistance. However, the physicochemical properties of each peptide need to be optimized for clinical use. To evaluate the effects of dimerization on the structure and biological activity of the antimicrobial peptide Ctx-Ha, we have synthesized the monomeric and three dimeric (Lys-branched) forms of the Ctx-Ha peptide by solid-phase peptide synthesis using a combination of 9-fluorenylmethyloxycarbonyl (Fmoc) andt-butoxycarbonyl (Boc) chemical approaches. The antimicrobial activity assay showed that dimerization decreases the ability of the peptide to inhibit growth of bacteria or fungi; however, the dimeric analogs displayed a higher level of bactericidal activity. In addition, a dramatic increase (50 times) in hemolytic activity was achieved with these analogs. Permeabilization studies showed that the rate of carboxyfluorescein release was higher for the dimeric peptides than for the monomeric peptide, especially in vesicles that contained sphingomyelin. Despite different biological activities, the secondary structure and pore diameter were not significantly altered by dimerization. In contrast to the case for other dimeric cAMPs, we have shown that dimerization selectively decreases the antimicrobial activity of this peptide and increases the hemolytic activity. The results also show that the interaction between dimeric peptides and the cell wall could be responsible for the decrease of the antimicrobial activity of these peptides.

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Biocompatible Catanionic Vesicles from Arginine-Based Surfactants: A New Strategy to Tune the Antimicrobial Activity and Cytotoxicity of Vesicular Systems

Pharmaceutics ◽

10.3390/pharmaceutics12090857 ◽

2020 ◽

Vol 12 (9) ◽

pp. 857

Author(s):

Aurora Pinazo ◽

Ramon Pons ◽

Ana Marqués ◽

Maribel Farfan ◽

Anderson da Silva ◽

...

Keyword(s):

Antimicrobial Activity ◽

Charge Density ◽

Hemolytic Activity ◽

Colloidal Stability ◽

Low Cost ◽

Critical Aggregation Concentration ◽

Medium Size ◽

Colloidal Systems ◽

Single Chain ◽

Catanionic Vesicles

Their stability and low cost make catanionic vesicles suitable for application as drug delivery systems. In this work we prepared catanionic vesicles using biocompatible surfactants: two cationic arginine-based surfactants (the monocatenary Nα-lauroyl-arginine methyl ester—LAM and the gemini Nα,Nϖ-bis(Nα-lauroylarginine) α, ϖ-propylendiamide—C3(CA)2) and three anionic amphiphiles (the single chain sodium dodecanoate, sodium myristate, and the double chain 8-SH). The critical aggregation concentration, colloidal stability, size, and charge density of these systems were comprehensively studied for the first time. These catanionic vesicles, which form spontaneously after mixing two aqueous solutions of oppositely charged surfactants, exhibited a monodisperse population of medium-size aggregates and good stability. The antimicrobial and hemolytic activity of the vesicles can be modulated by changing the cationic/anionic surfactant ratio. Vesicles with a positive charge efficiently killed Gram-negative and Gram-positive bacteria as well as yeasts; the antibacterial activity declined with the decrease of the cationic charge density. The catanionic systems also effectively eradicated MRSA (Methicillin-resistant Staphylococcus Aureus) and Pseudomonas aeruginosa biofilms. Interestingly, the incorporation of cholesterol in the catanionic mixtures improved the stability of these colloidal systems and considerably reduced their cytotoxicity without affecting their antimicrobial activity. Additionally, these catanionic vesicles showed good DNA affinity. Their antimicrobial efficiency and low hemolytic activity render these catanionic vesicles very promising candidates for biomedical applications.

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Structure-guided de novo design of α-helical antimicrobial peptide with enhanced specificity

Pure and Applied Chemistry ◽

10.1351/pac-con-09-01-12 ◽

2010 ◽

Vol 82 (1) ◽

pp. 243-257 ◽

Cited By ~ 15

Author(s):

Jin-Feng Huang ◽

Yi-Min Xu ◽

Dian-Ming Hao ◽

Yi-Bing Huang ◽

Yu Liu ◽

...

Keyword(s):

Antimicrobial Activity ◽

Amino Acid ◽

Hemolytic Activity ◽

De Novo ◽

Biological Activities ◽

Peptide Sequence ◽

Rational Approach ◽

Peptide Antibiotics ◽

Self Association ◽

Lysine Substitution

In the present study, the 26-residue peptide sequence Ac-KWKSFLKTFKSAKKTVLHTALKAISS-amide (peptide P) was utilized as the framework to study the effects of introducing hydrophilic amino acid lysine on the nonpolar face of the helix on peptide biological activities. Lysine residue was systematically used to substitute original hydrophobic amino acid at the selected locations on the nonpolar face of peptide P. In order to compensate for the loss of hydrophobicity caused by lysine substitution, leucine was also used to replace original alanine to increase peptide overall hydrophobicity. Hemolytic activity is correlated with peptide hydrophobicity. By introducing lysine on the nonpolar face, we significantly weaken peptide hemolytic activity as well as antimicrobial activity. However, by utilizing leucine to compensate the hydrophobicity, we improve antimicrobial activity against both Gram-negative and -positive bacteria. Peptide self-association ability and hydrophobicity were also determined. This specific rational approach of peptide design could be a powerful method to optimize antimicrobial peptides with clinical potential as peptide antibiotics.

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Evaluating the Bioactivity of a Novel Broad-Spectrum Antimicrobial Peptide Brevinin-1GHa from the Frog Skin Secretion of Hylarana guentheri and Its Analogues

Toxins ◽

10.3390/toxins10100413 ◽

2018 ◽

Vol 10 (10) ◽

pp. 413 ◽

Cited By ~ 8

Author(s):

Qi Chen ◽

Peng Cheng ◽

Chengbang Ma ◽

Xinping Xi ◽

Lei Wang ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Peptide ◽

Broad Spectrum ◽

Hemolytic Activity ◽

High Performance ◽

Disulfide Bridge ◽

Reversed Phase ◽

Central Position ◽

Skin Secretion ◽

Mass Spectral

Many antimicrobial peptides (AMPs) have been identified from the skin secretion of the frog Hylarana guentheri (H.guentheri), including Temporin, Brevinin-1, and Brevinin-2. In this study, an antimicrobial peptide named Brevinin-1GHa was identified for the first time by using ‘shotgun’ cloning. The primary structure was also confirmed through mass spectral analysis of the skin secretion purified by reversed-phase high-performance liquid chromatography (RP-HPLC). There was a Rana-box (CKISKKC) in the C-terminal of Brevinin-1GHa, which formed an intra-disulfide bridge. To detect the significance of Rana-box and reduce the hemolytic activity, we chemically synthesized Brevinin-1GHb (without Rana-box) and Brevinin-1GHc (Rana-box in central position). Brevinin-1GHa exhibited a strong and broad-spectrum antimicrobial activity against seven microorganisms, while Brevinin-1GHb only inhibited the growth of Staphylococcus aureus (S. aureus), which indicates Rana-box was necessary for the antimicrobial activity of Brevinin-1GHa. The results of Brevinin-1GHc suggested transferring Rana-box to the central position could reduce the hemolytic activity, but the antimicrobial activity also declined. Additionally, Brevinin-1GHa demonstrated the capability of permeating cell membrane and eliminating biofilm of S. aureus, Escherichia coli (E. coli), and Candida albicans (C. albicans). The discovery of this research may provide some novel insights into natural antimicrobial drug design.

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