We investigate the phase transition stages for detergent-mediated liposome solubilization of bio-mimetic membranes with the motivation of integrating membrane-bound Photosystem I into bio-hybrid opto-electronic devices. To this end, the interaction of two non-ionic detergents n-dodecyl-β-d-maltoside (DDM) and Triton X-100 (TX-100) with two types of phospholipids, namely DPhPC (1,2-diphytanoyl-sn-glycero-3-phosphocholine) and DPPG (1,2-dipalmitoyl-sn-glycero-3-phospho-(1′-rac-glycerol)), are examined. Specifically, solubilization processes for large unilamellar liposomes are studied with the aid of turbidity measurements, dynamic light scattering, and cryo-transmission electron microscopy imaging. Our results indicate that the solubilization process is well depicted by a three-stage model, wherein the lamellar-to-micellar transitions for DPhPC liposomes are dictated by the critical detergent/phospholipid ratios. The solubilization of DPhPC by DDM is devoid of formation of a “gel-like” phase. Furthermore, our results indicate that DDM is a stable candidate for DPhPC solubilization and proteoliposome formation. Finally, although the solubilization of DPPG with DDM indicated the familiar three-stage process, the same process with TX-100 indicate structural deformation of vesicles into complex network of kinetically trapped micro- and nanostructured arrangements of lipid bilayers.
Bibliographical noteFunding Information:
The authors would like to acknowledge the University of Tennessee Advanced Microscopy and Imaging Center for instrument use, scientific and technical assistance. This work was funded by Sustainable Energy Education and Research Center (SEERC) at University of Tennessee, Knoxville.
© 2016, Springer Science+Business Media New York.
- DPhPC and DPPG
- Detergent-mediated liposome solubilization
- Lamellar-to-complex structures
- Lamellar-to-micellar transition
- Transmission electron microscopy
- n-dodecyl-β-d-maltoside (DDM) and Triton X-100 (TX-100)