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

2010 ◽  
Vol 82 (1) ◽  
pp. 243-257 ◽  
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.

scholarly journals Development of Antimicrobial Stapled Peptides Based on Magainin 2 Sequence

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 444
Author(s):  
Motoharu Hirano ◽  
Chihiro Saito ◽  
Hidetomo Yokoo ◽  
Chihiro Goto ◽  
Ryuji Kawano ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Hemolytic Activity ◽  
Helical Structure ◽  
Antimicrobial Activities ◽  
Side Chain ◽  
Membrane Disruption ◽  
Amino Acid Residues ◽  
Electrophysiological Measurements ◽  
Cell Membrane Disruption

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.

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

MedChemComm ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 896-900 ◽  
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.

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

2012 ◽  
Vol 56 (6) ◽  
pp. 3004-3010 ◽  
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.

scholarly journals Identification, Characterization, and Recombinant Expression of Epidermicin NI01, a Novel Unmodified Bacteriocin Produced by Staphylococcus epidermidis That Displays Potent Activity against Staphylococci

2011 ◽  
Vol 56 (3) ◽  
pp. 1539-1547 ◽  
Author(s):  
Stephanie Sandiford ◽  
Mathew Upton
Keyword(s):  
Antimicrobial Activity ◽  
Structural Gene ◽  
Staphylococcus Epidermidis ◽  
De Novo ◽  
Sequence Data ◽  
Recombinant Expression ◽  
Draft Genome ◽  
Peptide Sequence ◽  
Content Type ◽  
Wide Range

ABSTRACTWe describe the discovery, purification, characterization, and expression of an antimicrobial peptide, epidermicin NI01, which is an unmodified bacteriocin produced byStaphylococcus epidermidisstrain 224. It is a highly cationic, hydrophobic, plasmid-encoded peptide that exhibits potent antimicrobial activity toward a wide range of pathogenic Gram-positive bacteria including methicillin-resistantStaphylococcus aureus(MRSA), enterococci, and biofilm-formingS. epidermidisstrains. Purification of the peptide was achieved using a combination of hydrophobic interaction, cation exchange, and high-performance liquid chromatography (HPLC). Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) analysis yielded a molecular mass of 6,074 Da, and partial sequence data of the peptide were elucidated using a combination of tandem mass spectrometry (MS/MS) andde novosequencing. The draft genome sequence of the producing strain was obtained using 454 pyrosequencing technology, thus enabling the identification of the structural gene using thede novopeptide sequence data previously obtained. Epidermicin NI01 contains 51 residues with four tryptophan and nine lysine residues, and the sequence showed approximately 50% identity to peptides lacticin Z, lacticin Q, and aureocin A53, all of which belong to a new family of unmodified type II-like bacteriocins. The peptide is active in the nanomolar range againstS. epidermidis, MRSA isolates, and vancomycin-resistant enterococci. Other unique features displayed by epidermicin include a high degree of protease stability and the ability to retain antimicrobial activity over a pH range of 2 to 10, and exposure to the peptide does not result in development of resistance in susceptible isolates. In this study we also show the structural gene alone can be cloned intoEscherichia colistrain BL21(DE3), and expression yields active peptide.

scholarly journals Rationale-Based,De NovoDesign of Dehydrophenylalanine-Containing Antibiotic Peptides and Systematic Modification in Sequence for Enhanced Potency

2011 ◽  
Vol 55 (5) ◽  
pp. 2178-2188 ◽  
Author(s):  
Sarika Pathak ◽  
Virander Singh Chauhan
Keyword(s):  
Antimicrobial Activity ◽  
Unnatural Amino Acids ◽  
De Novo ◽  
Peptide Antibiotics ◽  
Content Type ◽  
Microbial Drug Resistance ◽  
Proteolytic Resistance ◽  
Fundamental Information ◽  
Transmission Electron ◽  
Antibiotic Peptides

ABSTRACTIncreased microbial drug resistance has generated a global requirement for new anti-infective agents. As part of an effort to develop new, low-molecular-mass peptide antibiotics, we used a rationale-based minimalist approach to design short, nonhemolytic, potent, and broad-spectrum antibiotic peptides with increased serum stability. These peptides were designed to attain an amphipathic structure in helical conformations. VS1 was used as the lead compound, and its properties were compared with three series of derivates obtained by (i) N-terminal amino acid addition, (ii) systematic Trp substitution, and (iii) peptide dendrimerization. The Trp substitution approach underlined the optimized sequence of VS2 in terms of potency, faster membrane permeation, and cost-effectiveness. VS2 (a variant of VS1 with two Trp substitutions) was found to exhibit good antimicrobial activity against both the Gram-negativeEscherichia coliand the Gram-positive bacteriumStaphylococcus aureus. It was also found to have noncytolytic activity and the ability to permeate and depolarize the bacterial membrane. Lysis of the bacterial cell wall and inner membrane by the peptide was confirmed by transmission electron microscopy. A combination of small size, the presence of unnatural amino acids, high antimicrobial activity, insignificant hemolysis, and proteolytic resistance provides fundamental information for thede novodesign of an antimicrobial peptide useful for the management of infectious disease.

scholarly journals Broad-Spectrum Antimicrobial Activity and Improved Stability of a D-Amino Acid Enantiomer of DMPC-10A, the Designed Derivative of Dermaseptin Truncates

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 627
Author(s):  
Yu Zai ◽  
Yuan Ying ◽  
Zhuming Ye ◽  
Mei Zhou ◽  
Chengbang Ma ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Broad Spectrum ◽  
Hemolytic Activity ◽  
Galleria Mellonella ◽  
Amino Acid Residues ◽  
Antibiotic Resistant ◽  
Promising Alternative ◽  
Improved Stability ◽  
Amino Acid Enantiomer

DMPC-10A (ALWKKLLKK-Cha-NH2) is a 10-mer peptide derivative from the N-terminal domain of Dermaseptin-PC which has shown broad-spectrum antimicrobial activity as well as a considerable hemolytic effect. In order to reduce hemolytic activity and improve stability to endogenous enzymes, a D-amino acid enantiomer (DMPC-10B) was designed by substituting all L-Lys and L-Leu with their respective D-form amino acid residues, while the Ala1 and Trp3 remained unchanged. The D-amino acid enantiomer exhibited similar antimicrobial potency to the parent peptide but exerted lower cytotoxicity and hemolytic activity. Meanwhile, DMPC-10B exhibited remarkable resistance to hydrolysis by trypsin and chymotrypsin. In addition to these advantages, DMPC-10B exhibited an outstanding antibacterial effect against Methicillin-resistant Staphylococcus aureus (MRSA) and Klebsiella pneumoniae using the Galleria mellonella larva model and displayed synergistic activities with gentamicin against carbapenem-resistant K. pneumoniae strains. This indicates that DMPC-10B would be a promising alternative for treating antibiotic-resistant pathogens.

scholarly journals Discovery and characterisation of novel circular bacteriocin plantacyclin B21AG from Lactobacillus plantarum B21

2020 ◽  
Author(s):  
Aida Golneshin ◽  
Mian Chee Gor ◽  
Ben Vezina ◽  
Nicholas Williamson ◽  
Thi Thu Hao Van ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Lactobacillus Plantarum ◽  
De Novo ◽  
Peptide Sequencing ◽  
Exchange Chromatography ◽  
Leader Peptide ◽  
Proteolytic Resistance ◽  
Wide Range ◽  
Circular Bacteriocin

AbstractLactobacillus plantarum B21 isolated from Vietnamese sausage (nem chua) has previously displayed broad antimicrobial activity against gram positive bacteria including foodborne pathogens Listeria monocytogenes and Clostridium perfringens. This study successfully identified the antimicrobial agent as plantacyclin B21AG, a 5668 Da circular bacteriocin demonstrating high thermostability, resistance to a wide range of pH, proteolytic resistance and temporal stability. We report a reverse genetics approach used to identify and characterise plantacyclin B21AG. The bacteriocin was purified from culture supernatant by a short process consisting of concentration, n-butanol extraction and cation exchange chromatography. A de novo peptide sequencing using LC-MS/MS techniques identified two putative peptide fragments which were mapped to the genome of Lactobacillus plantarum B21. This revealed an ORF corresponding to a putative circular bacteriocin with a 33-amino acid leader peptide and 58-amino acid mature peptide found on native plasmid pB21AG01. The corresponding gene cluster, consisted of seven genes associated with post-translational circularisation, immunity and secretion. The robust nature of plantacyclin B21AG, its antimicrobial activity and associated machinery for cyclisation make it an interesting biotechnological target for further development, and application as a food-safe antimicrobial.

scholarly journals In Silico Identification and Biological Evaluation of Antimicrobial Peptides Based on Human Cathelicidin LL-37

2006 ◽  
Vol 50 (9) ◽  
pp. 2983-2989 ◽  
Author(s):  
Thorgerdur Sigurdardottir ◽  
Pia Andersson ◽  
Mina Davoudi ◽  
Martin Malmsten ◽  
Artur Schmidtchen ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
In Silico ◽  
In Silico Analysis ◽  
Biological Evaluation ◽  
Binding Activity ◽  
Multiple Organ ◽  
Peptide Antibiotics ◽  
Cultured Smooth Muscle Cells

ABSTRACT Bacterial lipopolysaccharides (LPS) are important triggers of the widespread inflammatory response, which contributes to the development of multiple organ failure during sepsis. The helical 37-amino-acid-long human antimicrobial peptide LL-37 not only possesses a broad-spectrum antimicrobial activity but also binds and neutralizes LPS. However, the use of LL-37 in sepsis treatment is hampered by the fact that it is also cytotoxic. To find a less toxic analog of LL-37, we used in silico analysis to identify amphipathic helical regions of LL-37. A 21-amino-acid fragment (GKE) was synthesized, the biological actions of which were compared to those of two equally long peptides derived from the N and C termini of LL-37 as well as native LL-37. GKE displayed antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Candida parapsilosis that was similar to or even stronger than LL-37. GKE, as well as the equally long control peptides, attracted granulocytes in a fashion similar to that of LL-37, while only GKE was as potent as LL-37 in inhibiting LPS-induced vascular nitric oxide production. GKE caused less hemolysis and apoptosis in human cultured smooth muscle cells than LL-37. In summary, we have identified an active domain of LL-37, GKE, which displays antimicrobial activity in vitro and LPS-binding activity similar to those of LL-37 but is less toxic. GKE therefore holds promise as a template for the development of peptide antibiotics for the treatment of sepsis.

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