A neutron diffraction study of purple membranes under pressure.
Neutron diffraction from hydrated stacks of natural two-dimensional crystal patches of purple membrane from Halobacterium salinarum was studied as a function of pressure. Measurements in H(2)O and D(2)O permitted the determination of the distribution of water of hydration in the in-plane projection of the membrane. The main experimental difference observed between the samples at 300 MPa and atmospheric pressure was a major reorganization of the hydration around the lipid head groups and protein, associated with a protein conformational change and small reductions in lamellar (stacking) and in-plane lattice spacings, which was consistent with the compressibility of membrane-protein and lipid components.
Institut de Biologie Structurale, Grenoble, France.
Isabelle Gundel
IG
Rossand
Giuseppe
G
Zaccai
Giovanna
G
Fragneto
D001274:Atmospheric Pressure; D003903:Deuterium / Q000737:chemistry / Q000378:metabolism; D019617:Halobacterium salinarum / Q000254:growth & development / Q000378:metabolism; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D033363:Neutron Diffraction; D009502:Neutrons; D018717:Purple Membrane / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature; D014867:Water / Q000737:chemistry / Q000378:metabolism
D008563:Membrane Lipids; D008565:Membrane Proteins; D014867:Water; D003903:Deuterium