Comparing Bacterial Membrane Interactions of Antimicrobial Peptides and Their Mimics
Interactions with bacterial membranes are integral to the mechanisms of action of all antimicrobial peptides (AMPs), regardless of their final cellular targets. Here, we describe in detail two biophysical techniques that can be used to measure the membrane activities of AMPs and antimicrobial peptidomimetics: (1) a calcein leakage assay to investigate interactions between AMPs/peptidomimetics with large unilamellar vesicles and (2) a potential-sensitive dye-based depolarization assay to investigate interactions with the membranes of live bacteria. By comparing the membrane interactions of AMPs and their mimics, these techniques can provide insights into their extent of mimicry and their antimicrobial mechanisms.
Key wordsCalcein leakage large unilamellar vesicles membrane depolarization membrane potential diSC3–5
The authors would like to thank Professor Robert MacDonald, Dr. Joshua Rausch, Dr. Jiwon Seo, and Ms. Meera Rao for their assistance in the development of these protocols. This work was supported by a Department of Homeland Security Fellowship and NIH Grants 1 R01 HL67984 and 1 R01 AI072666.
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