biostudies-literatureUnknown103(3)Ulmschneider JPThe membrane-active antimicrobial peptide PGLa from Xenopus laevis is known from solid-state (2)H-, (15)N-, and (19)F-NMR spectroscopy to occupy two distinct α-helical surface adsorbed states in membranes: a surface-bound S-state with a tilt angle of ~95° at low peptide/lipid molar ratio (P/L = 1:200), and an obliquely tilted T-state with a tilt angle of 127° at higher peptide concentration (P/L = 1:50). Using a rapid molecular-dynamics insertion protocol in combination with microsecond-scale simulation, we have characterized the structure of both states in detail. As expected, the amphiphilic peptide resides horizontally on the membrane surface in a monomeric form at a low P/L, whereas the T-state is seen in the simulations to be a symmetric antiparallel dimer, with close contacts betweenBiophysical journal472-482https://www.ebi.ac.uk/biostudies/studies/S-EPMC3414899biostudies-literatureReorientation and dimerization of the membrane-bound antimicrobial peptide PGLa from microsecond all-atom MD simulations.PMC3414899Ulrich ASUlmschneider MBUlmschneider JPSmith JCStrandberg EfalseReorientation and dimerization of the membrane-bound antimicrobial peptide PGLa from microsecond all-atom MD simulations.The membrane-active antimicrobial peptide PGLa from Xenopus laevis is known from solid-state (2)H-, (15)N-, and (19)F-NMR spectroscopy to occupy two distinct α-helical surface adsorbed states in membranes: a surface-bound S-state with a tilt angle of ~95° at low peptide/lipid molar ratio (P/L = 1:200), and an obliquely tilted T-state with a tilt angle of 127° at higher peptide concentration (P/L = 1:50). Using a rapid molecular-dynamics insertion protocol in combination with microsecond-scale simulation, we have characterized the structure of both states in detail. As expected, the amphiphilic peptide resides horizontally on the membrane surface in a monomeric form at a low P/L, whereas the T-state is seen in the simulations to be a symmetric antiparallel dimer, with close contacts between2012-01-01T00:00:00Z2012 Aug2025-04-04T21:18:07.881Z2019-03-27T00:56:32ZS-EPMC34148992294786310.1016/j.bpj.2012.06.040