Global small-angle X-ray scattering data analysis for multilamellar vesicles: the evolution of the scattering density...

Area of Science:

• Biophysics
• Materials Science
• Structural Biology

Background:

• The scattering density profile (SDP) model is a powerful tool for analyzing scattering data from unilamellar vesicles.
• Analyzing multilamellar vesicles (MLVs) presents unique challenges due to their complex structure.

Purpose of the Study:

• To adapt the SDP model for analyzing fully hydrated, liquid crystalline MLVs.
• To extract high-resolution structural information and determine bilayer elastic bending fluctuations from standalone X-ray data.

Main Methods:

• Development of a genetic algorithm-based SDP model for MLV analysis.
• Application of the model to X-ray scattering data from MLVs.

Main Results:

• The adapted SDP model successfully determined structural parameters like bilayer thickness and area per lipid for various lipids and cholesterol mixtures.
• Results were consistent with previous studies using combined neutron and X-ray data.
• Incorporating neutron data improved lipid backbone details but not structural parameters within experimental error.

Conclusions:

• The adapted SDP model offers a robust method for high-resolution structural analysis of MLVs using X-ray scattering.
• This approach simplifies data acquisition by not requiring neutron scattering data for key structural insights.