Abstract
The antimicrobial peptides (AMPs) PGLa and magainin 2 (MAG2) found in the skin of the African frog Xenopus laevis show a synergistic enhancement of their activity [1]. Both peptides form amphipathic α-helices when binding to a lipid membrane, and their orientation in membranes have been determined with high accuracy using solid state 2H-, 15N-, and 19F-NMR.We have previously shown that PGLa inserts into DMPC/DMPG bilayers in the presence of an equimolar amount of MAG2, but not on its own, even at high concentrations [2]. This indicates formation of stable heterodimeric peptide pores, which in turn can explain the synergism between the peptides. Here, we show that MAG2, both with and without PGLa, always stays almost flat on the membrane surface; however, there is a small change in the orientation in the presence of PGLa, and dynamics is reduced, indicating that a PGLa-MAG2 complex is formed. In POPC/POPG, both peptides stay flat on the membrane surface, alone or combined. This is in agreement with our previous finding that the AMP MSI-103 always stays flat on the surface in unsaturated lipids (or more generally in lipid systems with negative spontaneous curvature), but can insert deeper into the membrane in saturated lipids (where the spontaneous curvature is positive) [3].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.