title: Electrostatic induction of lipid asymmetry.
abstract: The asymmetric arrangement of phospholipids between the two leaflets of the plasma membrane of eukaryotic cells is an integral part of cellular function. ATP-dependent translocases capable of selective lipid transport across the membrane are believed to play a role in this lipid asymmetry, but our understanding of this process is incomplete. Here we show the first direct and quantitative experiments demonstrating the induction of phosphatidylserine asymmetry in a membrane by electrostatic association of poly-l-lysine in an attempt to elucidate the complex factors which govern the establishment and maintenance of lipid compositional asymmetry in the plasma membrane on a fundamental level. The attractive electrostatic interactions between the charged surface-associated polylysine and phosphatidylserine are sufficient to both induce and maintain an asymmetric arrangement of phosphatidylserine in a planar supported membrane, as measured by sum-frequency vibrational spectroscopy. These studies provide a glimpse of the physical and chemical underpinnings of lipid asymmetry in the eukaryotic plasma membrane.
authors: Department of Chemistry, University of Utah, 315 South 1400 East Room 2020, Salt Lake City, Utah 84112, USA.
authors: Krystal L
authors: KL
authors: Brown
authors: John C
authors: JC
authors: Conboy