creating knowledge for future



High Quality


Scholarly Publishing
                CAREER NETWORK  
         
World's one of the largest Research
Career Network
Benefits
  •     Academic & Industry jobs
  •     Project funding
  •     Visiting faculty positions
  •     Visiting scientist positions
  •     Invited talks
  •     and more...  
   
Register FREE  
 
 
 
 
 
  Physics Express 2014, 4: 6
  Research Article
 
X-ray diffraction and confocal fluorescence microscopy studies on the effect of cholesterol on phospholipid membranes
  Sanat Karmakara, V. A. Raghunathanb  
     
a Department of Physics, Jadavpur University, 188 Raja S. C. mallick Road, Kolkata, 700 032, India
b Raman Research Institute, Shadashivanagar, Bangaluru, 5600 80, India

   
  Abstract  
  We have studied the influence of cholesterol on the bilayer properties of phospholipid membranes using small angle x-ray scattering and laser scanning confocal fluorescence microscopy. We have obtained a cholesterol induced modulated (Pβ) phase in oriented multilayers of dipalmitoyl phosphatidylcholine (DPPC)-cholesterol mixtures at 98% relative humidity at intermediate cholesterol concentrations. The Pβ phase, which is distinct from the usual ripple (Pβ') phase, is absent in unoriented samples in excess water. However, we observe enhanced swelling of the bilayers in this part the phase diagram. This results is also supported by the fact that giant unilamellar vesicles (GUVs) at small cholesterol concentration (< 10 mol%) show significant shape fluctuations, indicating softening of bilayers in the presence of cholesterol. However, interestingly smaller GUVs (diameter < 20 µm) are almost spherical in shape and show dark irregular domains on a bright background, indicating the coexistence of gel and fluid phases.
     
  Keywords  
  Model membrane; Small angle x-ray diffraction; Fluorescence microscopy  
     
   
   
   
   
     

  © 2016 Cognizure