Biological Membranes
Penghui LinNov. 15. 2013
Membranes
http://www.uvm.edu/~inquiryb/webquest/fa06/mvogenbe/
Diffusion across plasma membrane
http://en.wikipedia.org/wiki/Cell_membrane
Plasma Membrane
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Man-made membrane
http://bioweb.wku.edu/courses/biol115/wyatt/biochem/lipid/Lipid_2.asp
Liquid crystals
• Nematic phase
• Smectic phases
• Chiral phases
http://en.wikipedia.org/wiki/Liquid_crystal
Sample preparation
Jörg Fitter, Thomas Gutberlet, John Katsaras. Neutron Scattering in Biology, Techniques and Applications. 2006 ISBN: 978-3-540-29108-4 (Print) 978-3-540-29111-4 (Online)
Incident angle = reflected angle
Specular Neutron Reflectivity
Jörg Fitter, Thomas Gutberlet, John Katsaras. Neutron Scattering in Biology, Techniques and Applications. 2006 ISBN: 978-3-540-29108-4 (Print) 978-3-540-29111-4 (Online)
Density profile ρ0(z)
Fourier Synthesis
Jörg Fitter, Thomas Gutberlet, John Katsaras. Neutron Scattering in Biology, Techniques and Applications. 2006 ISBN: 978-3-540-29108-4 (Print) 978-3-540-29111-4 (Online)
Lipid bilayer phases
Location of Cholesterol
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Location of cholesterol
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Forces between membranes
Disjoining pressureOsmotic pressure
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Osmotic stress experiment
Neutron/
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Thermal unbinding
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Single component membrane
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Lipid mixtures and domains
• Ideal mixing: no phase separation
• Non-ideal or non-random mixing: compositional fluctuation happens while no stable domains formed
• Macroscopic phase separation: micron-size stable lipid domains are formed
No phase separation
Membranethickness
Fluctuationparameter
in DMPC bilayers at 35°Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Macroscopic phase separation
DPPC/DOPC/cholesterol
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Supramolecular properties
Diffused scattering
Tilted phase
Interdigitated phase
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Bicelle mixtures
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Bicelle mixtures
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Fluctuation change upon antimicrobial peptide binding
Jörg Fitter, Thomas Gutberlet, John Katsaras. Neutron Scattering in Biology, Techniques and Applications. 2006 ISBN: 978-3-540-29108-4 (Print) 978-3-540-29111-4 (Online)
Membrane rigidity change
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Pabst G. Applications of neutron and X-ray scattering to the study of biologically relevant model membranes J.Chem Phys Lipids. 2010 Jun;163(6):460-79
Thanks!
Jörg Fitter, Thomas Gutberlet, John Katsaras. Neutron Scattering in Biology, Techniques and Applications. 2006 ISBN: 978-3-540-29108-4 (Print) 978-3-540-29111-4 (Online)