Abstract

Inverse bicontinuous cubic structures formed by lipids have been demonstrated in a wide variety of applications, from a host matrix for proteins for crystallisation, to templates for nanoscale structures. Recent work has focused on tuning their properties to realize such applications, often by manipulating the structure by introducing other lipids with different properties such as charge or packing. However, they are often prepared in the presence of solutions containing salt, counteracting the effects, for example, charged lipids, and fundamentally changing the structures obtained. Here, we demonstrate the delicate interplay between electrostatic swelling in bicontinuous structures formed by monoolein (MO) doped with both negatively charged dioleyl phosphatidylglycerol (DOPG), and zwitterionic dioleyl phosphatidylethanolamine (DOPE), with the addition of mono- and divalent salts. The effect of adding salt to the charged phase changes the structure from the primitive cubic ({{bf{Q}}}_{II}^{P}) to the double diamond phase ({{bf{Q}}}_{II}^{D}) whilst still allowing for modest increases in lattice parameter of up to a nanometer. Contrasting this, the addition of salts to the non-charged phase, has minimal effect on the lattice parameter but now the transition from the ({{bf{Q}}}_{II}^{D}) to the inverse hexagonal phase (HII) is observed occurring at higher mole fractions of DOPE than in pure water.

Highlights

  • Inverse bicontinuous cubic structures formed by lipids have been demonstrated in a wide variety of applications, from a host matrix for proteins for crystallisation, to templates for nanoscale structures

  • We demonstrate the delicate interplay between electrostatic swelling in bicontinuous structures formed by monoolein (MO) doped with both negatively charged dioleyl phosphatidylglycerol (DOPG), and zwitterionic dioleyl phosphatidylethanolamine (DOPE), with the addition of mono- and divalent salts

  • In this work, we systematically investigate the effects of mono- and divalent salts on the structural parameters of a lipid cubic phase formed from a mixture of the monoacyl glycerol lipid, monoolein (MO) in the presence of either the anionic phospholipid dioleylphosphotidyl glycerol (DOPG) or the zwitterionic phospholipid dioleylphosphotidyl ethanolamine (DOPE) in order to better understand the interplay between

Read more

Summary

Introduction

Inverse bicontinuous cubic structures formed by lipids have been demonstrated in a wide variety of applications, from a host matrix for proteins for crystallisation, to templates for nanoscale structures. The self-assembly of biological amphiphiles such as lipids continues to be a rich area of research, from the fundamental understanding of the formation of biological membranes, through technological applications such as membrane protein crystallization and templating of nanoscale structures[1,2,3,4,5]. This is driven in part driven through the diverse range of structures which they are able to form - structures which are based on the desire for the lipids to adopt phases with varying degrees of negative curvature[6].

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call