An antimicrobial peptide with an aggregation-induced emission (AIE) luminogen for studying bacterial membrane interactions and antibacterial actions

2017 ◽  
Vol 53 (23) ◽  
pp. 3315-3318 ◽  
Author(s):  
Ning Ning Li ◽  
Jun Zhi Li ◽  
Peng Liu ◽  
Dicky Pranantyo ◽  
Lei Luo ◽  
...  

A fluorescence technique to investigate the interactions between bacterial membranes and an AIE luminogen-decorated antimicrobial peptide has been reported.

2021 ◽  
Vol 8 ◽  
Author(s):  
Qun Wang ◽  
Bo Peng ◽  
Mingyue Song ◽  
Abdullah ◽  
Jun Li ◽  
...  

Previous studies from our lab have shown that the antimicrobial peptide F1 obtained from the milk fermentation by Lactobacillus paracasei FX-6 derived from Tibetan kefir was different from common antimicrobial peptides; specifically, F1 simultaneously inhibited the growth of Gram-negative and Gram-positive bacteria. Here, we present follow-on work demonstrating that after the antimicrobial peptide F1 acts on either Escherichia coli ATCC 25922 (E. coli) or Staphylococcus aureus ATCC 63589 (S. aureus), their respective bacterial membranes were severely deformed. This deformation allowed leakage of potassium and magnesium ions from the bacterial membrane. The interaction between the antimicrobial peptide F1 and the bacterial membrane was further explored by artificially simulating the bacterial phospholipid membranes and then extracting them. The study results indicated that after the antimicrobial peptide F1 interacted with the bacterial membranes caused significant calcein leakage that had been simulated by different liposomes. Furthermore, transmission electron microscopy observations revealed that the phospholipid membrane structure was destroyed and the liposomes presented aggregation and precipitation. Quartz Crystal Microbalance with Dissipation (QCM-D) results showed that the antimicrobial peptide F1 significantly reduced the quality of liposome membrane and increased their viscoelasticity. Based on the study's findings, the phospholipid membrane particle size was significantly increased, indicating that the antimicrobial peptide F1 had a direct effect on the phospholipid membrane. Conclusively, the antimicrobial peptide F1 destroyed the membrane structure of both Gram-negative and Gram-positive bacteria by destroying the shared components of their respective phospholipid membranes which resulted in leakage of cell contents and subsequently cell death.


2016 ◽  
Vol 7 (7) ◽  
pp. 4613-4623 ◽  
Author(s):  
D. S. S. M. Uppu ◽  
M. M. Konai ◽  
U. Baul ◽  
P. Singh ◽  
T. K. Siersma ◽  
...  

The important role of hydrogen bonding in the interactions of cationic-amphiphilic polymers with bacterial membranes has been reported.


Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 831
Author(s):  
Jonggwan Park ◽  
Jun Hee Oh ◽  
Hee Kyoung Kang ◽  
Moon-Chang Choi ◽  
Chang Ho Seo ◽  
...  

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 C. suffuses, was found to exhibit antimicrobial activity against bacteria such as Listeria monocytogenes, Streptococcus suis, Campylobacter jejuni, and Salmonella typhimurium that cause zoonotic diseases. Moreover, the cytotoxicity and hemolytic activity of Css54 was lower than that of melittin isolated from bee venom. Circular dichroism assays showed that Css54 has an α-helix structure in an environment mimicking that of bacterial cell membranes. We examined the effect of Css54 on bacterial membranes using N-phenyl-1-naphthylamine, 3,3′-dipropylthiadicarbbocyanine iodides, SYTOX green, and propidium iodide. Our findings suggest that the Css54 peptide kills bacteria by disrupting the bacterial membrane. Moreover, Css54 exhibited antibiofilm activity against L. monocytogenes. Thus, Css54 may be useful as an alternative to antibiotics in humans and animal husbandry.


Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3420
Author(s):  
Marc Jofre ◽  
Lluís Jofre ◽  
Luis Jofre-Roca

The investigation of the electromagnetic properties of biological particles in microfluidic platforms may enable microwave wireless monitoring and interaction with the functional activity of microorganisms. Of high relevance are the action and membrane potentials as they are some of the most important parameters of living cells. In particular, the complex mechanisms of a cell’s action potential are comparable to the dynamics of bacterial membranes, and consequently focusing on the latter provides a simplified framework for advancing the current techniques and knowledge of general bacterial dynamics. In this work, we provide a theoretical analysis and experimental results on the microwave detection of microorganisms within a microfluidic-based platform for sensing the membrane potential of bacteria. The results further advance the state of microwave bacteria sensing and microfluidic control and their implications for measuring and interacting with cells and their membrane potentials, which is of great importance for developing new biotechnologically engineered systems and solutions.


Soft Matter ◽  
2021 ◽  
Author(s):  
Garima Rani ◽  
Kenichi Kuroda ◽  
Satyavani Vemparala

Using atomistic molecular dynamics simulations, we study the interaction of ternary methacrylate polymers, composed of charged cationic, hydrophobic and neutral polar groups, with model bacterial membrane. Our simulation data shows...


2017 ◽  
Vol 12 (4) ◽  
pp. 04E404 ◽  
Author(s):  
Lifang Niu ◽  
Thorsten Wohland ◽  
Wolfgang Knoll ◽  
Ingo Köper

2011 ◽  
Vol 64 (6) ◽  
pp. 798 ◽  
Author(s):  
David I. Fernandez ◽  
Marc-Antoine Sani ◽  
Frances Separovic

The interactions of the antimicrobial peptide, maculatin 1.1 (GLFGVLAKVAAHVVPAIAEHF-NH2) and two analogues, with model phospholipid membranes have been studied using solid-state NMR and circular dichroism spectroscopy. Maculatin 1.1 and the P15G and P15A analogues displayed minimal secondary structure in water, but with zwitterionic dimyristoylphosphatidylcholine (DMPC) vesicles displayed a significant increase in α-helical content. In mixed phospholipid vesicles of DMPC and anionic dimyristoylphosphatidylglycerol (DMPG), each peptide was highly structured with ~80% α-helical content. In DMPC vesicles, the native peptide displayed moderate head group interaction and significant perturbation of the lipid acyl chains. In DMPC/DMPG vesicles, maculatin 1.1 promoted formation of a DMPG-enriched phase and moderately increased disorder towards acyl chain ends of DMPC in the mixed bilayer. Both analogues showed reduced phospholipid head group interactions with DMPC but displayed significant interactions with the mixed lipid system. These effects support the preferential activity of these antimicrobial peptides for bacterial membranes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jiaxin Ding ◽  
Binbin Gao ◽  
Zhenhua Chen ◽  
Xifan Mei

Bacterial infection and its severe oxidative stress reaction will cause damage to skin cell mitochondria, resulting in long-lasting wound healing and great pain to patients. Thus, delayed wound healing in diabetic patients with Staphylococcus aureus infection is a principal challenge worldwide. Therefore, novel biomaterials with multifunction of bacterial membrane destruction and skin cell mitochondrial protection are urgently needed to be developed to address this challenge. In this work, novel gold cage (AuNCs) modified with epigallocatechin gallate (EGCG) were prepared to treat delayed diabetic wounds. The results showed that Au-EGCG had a high and stable photothermal conversion efficiency under near-infrared irradiation, and the scavenging rate of Au-EGCG for S. aureus could reach 95%. The production of large amounts of reactive oxygen species (ROS) leads to the disruption of bacterial membranes, inducing bacterial lysis and apoptosis. Meanwhile, Au-EGCG fused into hydrogel (Au-EGCG@H) promoted the migration and proliferation of human umbilical cord endothelial cells, reduced cellular mitochondrial damage and oxidative stress in the presence of infection, and significantly increased the basic fibroblast growth factor expression and vascular endothelial growth factor. In addition, animal studies showed that wound closure was 97.2% after 12 days of treatment, and the healing of chronic diabetic wounds was significantly accelerated. Au-EGCG nanoplatforms were successfully prepared to promote cell migration and angiogenesis in diabetic rats while removing S. aureus, reducing oxidative stress in cells, and restoring impaired mitochondrial function. Au-EGCG provides an effective, biocompatible, and multifunctional therapeutic strategy for chronic diabetic wounds.


2019 ◽  
Vol 123 (15) ◽  
pp. 3163-3176 ◽  
Author(s):  
Searle S. Duay ◽  
Gaurav Sharma ◽  
Rajeev Prabhakar ◽  
Alfredo M. Angeles-Boza ◽  
Eric R. May

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