1 HIV-1 matrix-31 membrane binding peptide interacts differently with membranes containing PS vs. PI(4,5)P 2 Running Title: MA 31 interacts differently with PS- or PIP 2 -membranes Lauren O’Neil 1 , Kathryn Andenoro 1 , Isabella Pagano 1 , Laura Carroll 1 , Leah Langer 1 , Zachary Dell 1 , Davina Perera 2 , Bradley W. Treece 1 , Frank Heinrich 1,3 , Mathias Lösche 1,3,4 , John F. Nagle 1 and Stephanie Tristram-Nagle 1* 1 Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213 2 Biomedical Engineering, Douglass College, Rutgers University, New Brunswick, NJ 08901 3 National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, MD 20899 4 Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 *Corresponding author, 412-268-3174, FAX: 412-681-0648, stn@cmu.edu , http://www.cmu.edu/biolphys/jfstn © 2016. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/