Chemically Locked Bicelles with High Thermal and Kinetic Stability

Abstract

In situ polymerization of ab icellar mixture composed of ap hospholipid and polymerizable surfactants afforded unprecedented stable bicelles.T he polymerized composite showed an aligned phase over aw ide thermal range (25 to > 90 8 8C) with excellent 2 Hquadrupole splitting of the solvent signal, thus implying versatility as an alignment medium for NMR studies.Crosslinking of the surfactants also brought favorable effects on the kinetic stability and alignment morphology of the bicelles.This system could thus offer anew class of scaffolds for biomembrane models.

Reversible Vesicle-to-Disk Transitions of Liposomes Induced by the Self-Assembly of Water-Soluble Porphyrins

“…34,35 Here, we assume that the interaction with rigid nanofibers of J-aggregates compensates for the energy required to form hydrophobic edges of disklike or sheetlike lipid structures. 14,15,36,37 UV−vis absorption spectra of porphyrin/DPPC composites support this idea. The spectroscopic aggregation number N for each J-aggregate was calculated from the full-width at half-maximum of the 491 nm J-aggregate absorption peak and the 433 nm monomer peak.…”

“…In particular, they exhibit flexible structural changes when interacting with flat substrates, 6,7 macromolecules, 8−12 or surfactants. 13,14 This enables applications such as the binding of biomolecules, surface patterning, and drug-delivery systems. Solid-supported lipid bilayers 6 are formed by the adhesion of liposomes on substrates, which results in a structural transition to a disk or sheet structure.…”

“…9 Aida et al prepared stable bilayer micelles (bicelles) via in situ polymerization of surfactants on the edge of the bicelle. 14 However, reversible structural transitions of liposomes, especially at the molecular level, remain a difficult challenge because it is difficult to control interactions of membranes with substrates or macromolecules. Here, we demonstrate reversible structural transformations of nanoscale vesicles to layered-disk structures, induced by interactions with anionic supramolecular porphyrin nanofibers (Figure 1).…”

Self-Assembled Rough Endoplasmic Reticulum-Like Proto-Organelles

“…In the past decades, scientists have developed a variety of model systems, including vesicles ( Deshpande et al., 2016 ), tubes ( Bi et al., 2014 ), supported or suspended lipid bilayers ( Tayebi et al., 2012 , Osaki and Takeuchi, 2017 , Fuhs et al., 2018 ), bicelles ( Dürr et al., 2012 ), and nanodisks ( Ravula et al., 2017 ). To further mimic the complexity of natural membrane systems, more complex membrane structures including multilamellar ( Matosevic and Paegel, 2013 ) and multicompartmented vesicles ( Zong et al., 2017 , Deng et al., 2017 ), stacked bicelles or nanodisks ( Matsui et al., 2015 , Yang et al., 2014 , Wang et al., 2018 ), and tube networks/stacks ( Karlsson et al., 2001 , Powers et al., 2017 , Zhang et al., 2017 ) were recently developed. These artificial membrane systems supplied platforms for the study of protein structures and functions ( Dürr et al., 2012 , Zhang et al., 2016 , Burré et al., 2010 ), the investigation of cellular processes ( Fenz et al., 2017 , Kamiya et al., 2016 , Küchler et al., 2016 ), and biomimetics ( Li and Han, 2018 , Altamura et al., 2017 , Adamala et al., 2016 , Heath et al., 2017 , Park et al., 2018 ), and provided important clues for membrane shaping ( Powers et al., 2017 , Shi and Baumgart, 2015 ).…”

Morphological Estimation of DMPC/DHPC Self-Assemblies in Diluted Condition: Based on Physicochemical Membrane Properties

“…In aqueous solution, long-chained saturated phospholipids (e.g., 1,2-dimyristoyl-snglycero-3-phosphocholine (DMPC, C14:0); melting temperature Tm = 23 ºC) often form bilayer membranes, that finally construct spherical vesicles due to the thermodynamic stability of the bilayers [6]. When short-chained phospholipid 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC, C6:0) is excessively added to a DMPC suspensions, they form micelle-like small assemblies at the total lipid concentration above the critical micelle concentration (CMC): for DHPC, the CMC is 15 mM [7,8]), in which the small bilayer morphology is also maintained [7,[9][10][11][12][13][14][15][16]. The morphology of small self-assemblies, such as micelle and bilayer-micelle (bicelle), can be dependent on the total lipid concentration, and on the lipid mixing ratio in lipid binary system [7].…”