Title
Improvement of lipidic bicontinuous cubic phases by the addition of a zwitterion with strong hydration ability and kosmotropicity
Author
Rika Takeuchi, Takahiro Ichikawa
Year
2019
Journal
New Journal of Chemistry
Abstract
Lyotropic bicontinuous cubic (QII) phases have attracted increasing attention as nanostructured fluidic matrices for some bio-polymers including enzymes and DNA. Owing to the 3D nature of the QII phases, the incorporated polymers show unique molecular behavior in the matrices. In many cases, monoolein (MO) is frequently employed as a lipid molecule because of its advanced ability to form QII phases under a wide range of conditions. However, there are still several aspects that require improvements in MO/water-based systems. In the present study, we have focused on the improvement of the temporal stability of MO/water-based QII matrices by the addition of a zwitterion. We have found that (I) the addition of 3-(1-methyl-3-imidazolio)propanesulfonate (ImZI) results in a decrease in the water activity of the MO/water-based matrices; (II) ImZI is a kosmotropic salt with structure-stabilizing effects on proteins; (III) a polypeptide, dermaseptin, forms a secondary structure in the MO/water/ImZI systems. These results suggest that the present lyotropic systems have great potential to be an ideal matrix for the lipidic cubic phase method that is known as a method to create single crystals of membrane proteins.
Instrument
J-720
Keywords
Circular dichroism, Secondary structure, Polymers, Biochemistry