Polydiacetylene Vesicles Acting as Colorimetric Sensor for the Detection of Plantaricin LD1 Purified From Lactobacillus Plantarum LD1

Mapping Intimacies ◽

10.21203/rs.3.rs-298007/v1 ◽

2021 ◽

Author(s):

Manoj Kumar Yadav ◽

Santosh Kumar Tiwari

Keyword(s):

Antimicrobial Peptides ◽

Lactobacillus Plantarum ◽

Pore Formation ◽

Membrane Lipids ◽

Membrane Disruption ◽

Target Cells ◽

Artificial Membrane ◽

Physiological Processes ◽

Colorimetric Response ◽

Pda Vesicles

Abstract The interaction of antimicrobial peptides with membrane lipids plays a major role in numerous physiological processes. Bacteriocins are antimicrobial peptides known to kill target cells by pore formation and membrane disruption. In this study, polydiacetylene (PDA) vesicles were applied as artificial membrane for detection of plantaricin LD1 purified from Lactobacillus plantarum LD1. Plantaricin LD1 (200 µg/ml) was able to change the color of PDA vesicles from blue to red with colorimetric response CR % 30.26 ± 0.59. Nisin (200 µg/ml), used as control, also changed the color of the vesicles with CR % 50.56 ± 0.98 validating the membrane-acting nature of these bacteriocins. The PDA vesicles treated with nisin and plantaricin LD1 showed increased infrared absorbance at 1411.46 cm-1 and 1000-1150 cm-1 indicated the interaction of bacteriocins with phospholipids and fatty acids, respectively. Further, microscopic examination also suggested the disruption of bacteriocin-treated vesicles indicating the interaction of bacteriocins. These findings suggest that the PDA vesicles may be used as bio-mimetic sensor for the detection of bacteriocins produced by several probiotics in food and therapeutic applications.

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Pore Forming Protein Induced Biomembrane Reorganization and Dynamics: A Focused Review

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2021.737561 ◽

2021 ◽

Vol 8 ◽

Author(s):

Ilanila Ilangumaran Ponmalar ◽

Nirod K. Sarangi ◽

Jaydeep K. Basu ◽

K. Ganapathy Ayappa

Keyword(s):

Pore Formation ◽

Membrane Lipids ◽

Md Simulations ◽

Correlation Spectroscopy ◽

Stimulated Emission ◽

Brownian Diffusion ◽

Target Cells ◽

Listeriolysin O ◽

Oligomeric State ◽

Pore Forming Proteins

Pore forming proteins are a broad class of pathogenic proteins secreted by organisms as virulence factors due to their ability to form pores on the target cell membrane. Bacterial pore forming toxins (PFTs) belong to a subclass of pore forming proteins widely implicated in bacterial infections. Although the action of PFTs on target cells have been widely investigated, the underlying membrane response of lipids during membrane binding and pore formation has received less attention. With the advent of superresolution microscopy as well as the ability to carry out molecular dynamics (MD) simulations of the large protein membrane assemblies, novel microscopic insights on the pore forming mechanism have emerged over the last decade. In this review, we focus primarily on results collated in our laboratory which probe dynamic lipid reorganization induced in the plasma membrane during various stages of pore formation by two archetypal bacterial PFTs, cytolysin A (ClyA), an α-toxin and listeriolysin O (LLO), a β-toxin. The extent of lipid perturbation is dependent on both the secondary structure of the membrane inserted motifs of pore complex as well as the topological variations of the pore complex. Using confocal and superresolution stimulated emission depletion (STED) fluorescence correlation spectroscopy (FCS) and MD simulations, lipid diffusion, cholesterol reorganization and deviations from Brownian diffusion are correlated with the oligomeric state of the membrane bound protein as well as the underlying membrane composition. Deviations from free diffusion are typically observed at length scales below ∼130 nm to reveal the presence of local dynamical heterogeneities that emerge at the nanoscale—driven in part by preferential protein binding to cholesterol and domains present in the lipid membrane. Interrogating the lipid dynamics at the nanoscale allows us further differentiate between binding and pore formation of β- and α-PFTs to specific domains in the membrane. The molecular insights gained from the intricate coupling that occurs between proteins and membrane lipids and receptors during pore formation are expected to improve our understanding of the virulent action of PFTs.

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Dimerization of the Antimicrobial Peptide Polyphemusin I into One Polypeptide Chain: Theoretical and Practical Consequences

Biotekhnologiya ◽

10.21519/0234-2758-2019-35-5-36-41 ◽

2019 ◽

Vol 35 (5) ◽

pp. 36-41

Author(s):

V.A. Zenin ◽

E.G. Sadykhov ◽

A.N. Fedorov

Keyword(s):

Antimicrobial Peptides ◽

Pore Formation ◽

Lipid Membrane ◽

Polypeptide Chain ◽

Unique Identifier ◽

Bacterial Cultures ◽

In Series ◽

The Russian Federation ◽

Peptide Dimerization ◽

Putative Mechanism

A strategy of sequential dimerization of monomers of antimicrobial peptides (AMPs) into one polypeptide chain has been implemented on the example of a beta-structural AMP polyphemusin I which is one of the most effective candidate for use as an antibiotic. The possible polyphemusin I monomer and dimer structures in lipid membrane were studied in this work via molecular modeling. To this end, these molecules were chemically synthesized so that the dimer represented two monomers connected in series into one polypeptide chain with a flexible linker. The antimicrobial effects of monomer and dimer were then tested on various bacterial cultures, and their similarity was shown. Therefore, we can conclude that the pore formation is not a putative mechanism of the polyphemusin I action. antimicrobial peptides, peptide dimerization, mechanism of antimicrobial action, polyphemusin The work was supported by the Ministry of Science and Higher Education of the Russian Federation (Project Unique Identifier RFMEFI57517X0151).

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Engineering “Antimicrobial Peptides” and Other Peptides to Modulate Protein-Protein Interactions in Cancer

Current Topics in Medicinal Chemistry ◽

10.2174/1568026620666201021141401 ◽

2020 ◽

Vol 20 (32) ◽

pp. 2970-2983

Author(s):

Samuel J.S. Rubin ◽

Nir Qvit

Keyword(s):

Antimicrobial Peptides ◽

Protein Interactions ◽

Anticancer Agents ◽

Cancer Therapeutics ◽

Target Cells ◽

Protein Protein Interactions ◽

Peptide Backbone ◽

Modified Peptides ◽

Selective Death ◽

Drug Leads

Antimicrobial peptides (AMPs) are a class of peptides found across a wide array of organisms that play key roles in host defense. AMPs induce selective death in target cells and orchestrate specific or nonspecific immune responses. Many AMPs exhibit native anticancer activity in addition to antibacterial activity, and others have been engineered as antineoplastic agents. We discuss the use of AMPs in the detection and treatment of cancer as well as mechanisms of AMP-induced cell death. We present key examples of cathelicidins and transferrins, which are major AMP families. Further, we discuss the critical roles of protein-protein interactions (PPIs) in cancer and how AMPs are well-suited to target PPIs based on their unique drug-like properties not exhibited by small molecules or antibodies. While peptides, including AMPs, can have limited stability and bioavailability, these issues can be overcome by peptide backbone modification or cyclization (e.g., stapling) and by the use of delivery systems such as cellpenetrating peptides (CPPs), respectively. We discuss approaches for optimizing drug properties of peptide and peptidomimetic leads (modified peptides), providing examples of promising techniques that may be applied to AMPs. These molecules represent an exciting resource as anticancer agents with unique therapeutic advantages that can target challenging mechanisms involving PPIs. Indeed, AMPs are suitable drug leads for further development of cancer therapeutics, and many studies to this end are underway.

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