Lipid-Detergent Phase Transitions During Detergent-Mediated Liposome Solubilization

Area of Science:

• Biophysics
• Materials Science
• Biochemistry

Background:

• Investigating detergent-mediated liposome solubilization is crucial for integrating membrane proteins into bio-hybrid opto-electronic devices.
• Understanding detergent-lipid interactions informs the development of stable proteoliposomes.

Purpose of the Study:

• To investigate the phase transition stages during detergent-mediated solubilization of bio-mimetic membranes.
• To evaluate n-dodecyl-β-D-maltoside (DDM) and Triton X-100 (TX-100) for solubilizing 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) and 1,2-dipalmitoyl-sn-glycero-3-phospho-(1 ahydro-rac-glycerol) (DPPG) liposomes.

Main Methods:

• Turbidity measurements
• Dynamic light scattering
• Cryo-transmission electron microscopy imaging

Main Results:

• Solubilization follows a three-stage model, with transitions governed by critical detergent/phospholipid ratios.
• DDM-mediated solubilization of DPhPC avoids "gel-like" phase formation and is suitable for proteoliposome formation.
• TX-100 solubilization of DPPG results in structural deformation, forming complex nanostructured lipid bilayers.

Conclusions:

• DDM is a stable detergent for DPhPC solubilization and proteoliposome formation.
• Different detergents induce distinct structural outcomes during liposome solubilization, impacting their suitability for specific applications.