Related Experiment Video
Updated: Feb 11, 2026

Tumor Hypoxia Assessment: In Vivo 3D Oxygen Imaging Through Electron Paramagnetic Resonance
Published on: February 14, 2025
Assessing topology and surface orientation of an antimicrobial peptide magainin 2 using mechanically aligned bilayers
Daniel J Mayo1, Indra D Sahu1, Gary A Lorigan1
1Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, United States.
Abstract:
Aligned CW-EPR membrane protein samples provide additional topology interactions that are absent from conventional randomly dispersed samples. These samples are aptly suited to studying antimicrobial peptides because of their dynamic peripheral topology. In this study, four consecutive substitutions of the model antimicrobial peptide magainin 2 were synthesized and labeled with the rigid TOAC spin label. The results revealed the helical tilts to be 66° ± 5°, 76° ± 5°, 70° ± 5°, and 72° ± 5° for the TOAC substitutions H7, S8, A9, and K10 respectively. These results are consistent with previously published literature. Using the EPR (electron paramagnetic resonance) mechanical alignment technique, these substitutions were used to critically assess the topology and surface orientation of the peptide with respect to the membrane. This methodology offers a rapid and simple approach to investigate the structural topology of antimicrobial peptides.
Related Concept Videos
Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals
SN2 Reaction: Mechanism
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...
Peptide Bonds
Paramagnetism
Resonance
UV–Vis Spectroscopy: Molecular Electronic Transitions

