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Updated: Jan 24, 2026
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Crystallizing Membrane Proteins for Structure Determination using Lipidic Mesophases
Published on: November 21, 2010
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Structure and Function in Antimicrobial Piscidins: Histidine Position, Directionality of Membrane Insertion, and
Mihaela Mihailescu1, Mirco Sorci2, Jolita Seckute3
1Institute for Bioscience and Biotechnology Research , University of Maryland , Rockville , Maryland 20850 , United States.
Journal of the American Chemical Society
|May 31, 2019
Summary
Piscidins p1 and p3 show distinct membrane interactions due to histidine content. Piscidin p1
Area of Science:
- Biophysics
- Biochemistry
- Membrane Biology
Background:
- Piscidins are histidine-rich antimicrobial peptides.
- They exhibit amphipathic alpha-helical structures.
- Their pH activity suggests biomedical potential.
Purpose of the Study:
- Investigate how histidine variations influence piscidin permeabilization.
- Compare the membrane interaction of piscidin p1 and p3.
- Elucidate pH-dependent activity and membrane insertion.
Main Methods:
- Neutron diffraction
- Dye leakage assays
- NMR-monitored titrations
- Molecular dynamics simulations
- Electrochemical impedance spectroscopy
Main Results:
- Piscidin p3 permeabilization is pH-sensitive, unlike p1.
- Piscidin p1 exhibits deeper membrane insertion and increased membrane disruption.
- Histidine content and amphipathicity dictate insertion directionality and pH resilience.
Conclusions:
- Histidine variations in piscidins lead to differential membrane permeabilization.
- Piscidin p1's unique histidine (H17) confers pH-resilient, deeper membrane insertion.
- Mechanistic insights into antimicrobial peptide-membrane interactions are provided.
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