title: Penetration of HIV-1 Tat47-57 into PC/PE Bilayers Assessed by MD Simulation and X-ray Scattering.
abstract: The interactions of the basic, cell-penetrating region (Y47GRKKRRQRRR57) of the HIV-1 Tat protein with dioleoylphosphatidylcholine (DOPC) bilayers were previously assessed by comparing experimental X-ray diffuse scattering with atomistic molecular dynamics simulations. Here, we extend this investigation by evaluating the influence of phosphatidylethanolamine (PE) lipids. Using experimental bilayer form factors derivedfrom X-ray diffuse scattering data as a guide, our simulations indicate that Tat peptides localize close to the carbonyl-glycerol group in the headgroup region of bilayers composed of either DOPC or DOPC:DOPE (1:1) lipid. Our results also suggest that Tat peptides may more frequently insert into the hydrophobic core of bilayers composed of PC:PE (1:1) lipids than into bilayers composed entirely of PC lipids. PE lipids may facilitate peptide translocation across a lipid bilayer by stabilizing intermediate states in which hydrated peptides span the bilayer.
authors.affiliation: Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, 110 8th St, Troy, NY 12180-3590, USA. candrewn@gmail.com.
authors.forename: Chris
authors.initials: C
authors.lastname: Neale
authors.affiliation: Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, 110 8th St, Troy, NY 12180-3590, USA. harryhuangkun@gmail.com.
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.affiliation: Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, 110 8th St, Troy, NY 12180-3590, USA. angel@rpi.edu.|Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th St, Troy, NY 12180-3590, USA. angel@rpi.edu.
authors.forename: Angel E
authors.initials: AE
authors.lastname: García
authors.affiliation: Biological Physics Group, Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA. stn@cmu.edu.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Tristram-Nagle
keywords: HIV-1 Tat; X-ray scattering; cell-penetrating peptide; lipid bilayers; molecular dynamics simulation; peptide translocation