On the existence of an amphotericin B – sterol complex in lipid vesicles and in propanol–water systems

1987 ◽  
Vol 65 (3) ◽  
pp. 234-238 ◽  
Author(s):  
Ilona Gruda ◽  
Jacques Bolard
Keyword(s):  
Circular Dichroism ◽  
Amphotericin B ◽  
Lipid Bilayer ◽  
Binary Mixtures ◽  
Lipid Vesicles ◽  
Water Systems ◽  
Phospholipid Vesicles ◽  
Positive Cooperativity ◽  
Circular Dichroïsm

The amphotericin B (AmB) – ergosterol complex, formed by interaction of the antibiotic with ergosterol-containing phospholipid vesicles, is associated with the lipid bilayer. It has been shown by circular dichroism studies that the AmB–ergosterol complex formed in water–propanol binary mixtures has a similar structure to that observed in phospholipid vesicles. A positive cooperativity is found for the interaction of AmB with ergosterol. The similar AmB–cholesterol complex is much less stable and rearranges rapidly to a different conformation.

scholarly journals Structural Analysis and Design of Chionodracine-Derived Peptides Using Circular Dichroism and Molecular Dynamics Simulations

2020 ◽  
Vol 21 (4) ◽  
pp. 1401
Author(s):  
Stefano Borocci ◽  
Giulia Della Pelle ◽  
Francesca Ceccacci ◽  
Cristina Olivieri ◽  
Francesco Buonocore ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Circular Dichroism ◽  
Lipid Membranes ◽  
Lipid Vesicles ◽  
Md Simulations ◽  
Structural Basis ◽  
Human Pathogens ◽  
Analysis And Design ◽  
Dynamics Simulations ◽  
Circular Dichroïsm

Antimicrobial peptides have been identified as one of the alternatives to the extensive use of common antibiotics as they show a broad spectrum of activity against human pathogens. Among these is Chionodracine (Cnd), a host-defense peptide isolated from the Antarctic icefish Chionodraco hamatus, which belongs to the family of Piscidins. Previously, we demonstrated that Cnd and its analogs display high antimicrobial activity against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species). Herein, we investigate the interactions with lipid membranes of Cnd and two analogs, Cnd-m3 and Cnd-m3a, showing enhanced potency. Using a combination of Circular Dichroism, fluorescence spectroscopy, and all-atom Molecular Dynamics (MD) simulations, we determined the structural basis for the different activity among these peptides. We show that all peptides are predominantly unstructured in water and fold, preferentially as α-helices, in the presence of lipid vesicles of various compositions. Through a series of MD simulations of 400 ns time scale, we show the effect of mutations on the structure and lipid interactions of Cnd and its analogs. By explaining the structural basis for the activity of these analogs, our findings provide structural templates to design minimalistic peptides for therapeutics.

scholarly journals Effect of imidazolium room-temperature ionic liquids on aggregation of amphotericin B: a circular dichroism study

RSC Advances ◽  
2015 ◽  
Vol 5 (98) ◽  
pp. 80325-80329 ◽  
Author(s):  
Laramie P. Jameson ◽  
Sergei V. Dzyuba
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Circular Dichroism ◽  
Amphotericin B ◽  
Room Temperature ◽  
Room Temperature Ionic Liquid ◽  
Room Temperature Ionic Liquids ◽  
Circular Dichroïsm

The aggregate–monomer equilibrium of amphotericin B could be controlled by the structure of the room-temperature ionic liquid.

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