In Situ Atomic Force Microscopy Studies of the Effect of Indolicidin on E.coli Cells


  • Peter Fojan Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, 9220 Aalborg, Denmark



Atomic force microscopy, indolicidin, antimicrobial peptides, E.coli cells, gelatin, honeycomb pattern, PLA, intracellular killing mechanism.


E.coli cells were succesfully attached to both gelatin coated surfaces and
polylactic acid honeycomb patterned mica surfaces as determined by in situ
atomic force microscopy. The gelatin coated surfaces provided a softer support
onto which the E.coli cells were capable of slightly submerging leading to a
better adhesion compared to the harder surfaces consisting of polylactic acid
polymer surfaces. After continuous scanning in liquid media, the E.coli cells
remained rod shaped and smooth. Indolicidin, a 13-AA linear antimicrobial
peptide, was injected in order to visualize the peptide-membrane interac-
tions in real time. Instantly after the injection of the peptides, the bacterial
membranes were observed to be distorted and seemed to melt proceeding as a
function of time. In conclusion, these experiments proved that the E.coli cells
were not ruptured as could be expected due to pore formation and disruption
of the osmotic pressure. This indicates a possible intracellular target killing
mechanism of indolicidin interacting with E.coli cells.


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Author Biography

Peter Fojan, Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, 9220 Aalborg, Denmark

Peter Fojan received his Ph.D. in Biotechnology at the University of tech-
nology Graz, Austria in 1997. He initially worked on industrial genetics of
eukaryotic organisms. During his postdoc time at Aalborg University at the
Department of Biotechnology he moved into the area of protein physics and
molecular modelling. With the startup of Nanotechnology at AAU he moved to
the Department of Physics and Nanotechnology where he became an Associate
Professor in 2009. His research interests are centered around biological and
small molecules and their interactions with cells and surfaces in general, for
medical, sensor applications and as antibacterial agents.


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How to Cite

Fojan, P. (2023). In Situ Atomic Force Microscopy Studies of the Effect of Indolicidin on E.coli Cells. Journal of Self Assembly and Molecular Electronics, 6(1), 13–34.