Lipid bilayer electrostatic energy, curvature stress, and assembly of gramicidin channels Academic Article uri icon

Overview

MeSH Major

  • Gramicidin
  • Ion Channels
  • Lipid Bilayers

abstract

  • Hydrophobic interactions between lipid bilayers and imbedded membrane proteins couple protein conformation to the mechanical properties of the bilayer. This coupling is widely assumed to account for the regulation of membrane protein function by the membrane lipids' propensity to form nonbilayer phases, which will produce a curvature stress in the bilayer. Nevertheless, there is only limited experimental evidence for an effect of bilayer curvature stress on membrane protein structure. We show that alterations in curvature stress, due to alterations in the electrostatic energy of dioleoylphosphatidylserine bilayers, modulate the structurally well-defined gramicidin A monomer <--> dimer reaction. Maneuvers that decrease the electrostatic energy of the unperturbed bilayer promote channel dissociation; we measure the change in interaction energy. The bilayer electrostatic energy thus can affect membrane protein structure by a mechanism that does not involve the electrostatic field across the bilayer, but rather electrostatic interactions among the phospholipid head groups in each monolayer which affect the bilayer curvature stress. These results provide further evidence for the importance of mechanical interactions between a bilayer and its imbedded proteins for protein structure and function.

publication date

  • May 13, 1997

Research

keywords

  • Academic Article

Identity

Language

  • eng

Digital Object Identifier (DOI)

  • 10.1021/bi9619841

PubMed ID

  • 9153409

Additional Document Info

start page

  • 5695

end page

  • 701

volume

  • 36

number

  • 19