Journal Article

Structure of Supramers Formed by the Amphiphile Biotin‐CMG‐DOPE

Henry, Stephen, Nizovtsev, Alexey, Ryzhov, Ivan, Zalygin, Anton, Oleinikov, Vladimir, Korchagina, Elena, Shtykova, Eleonora, Schaefer, Marcel, Solovyeva, Daria, Volynsky, Pavel, Bovin, Nicolai, Vaskan, Ivan, Mochalov, Konstantin, Tuzikov, Alexander, Efremov, Roman

2020

Overview

The synthetic function‐spacer‐lipid (FSL) amphiphile biotin‐CMG‐DOPE is widely used for delicate ligation of living cells with biotin residues under physiological conditions. Since this molecule has an “apolar‐polar‐hydrophobic” gemini structure, the supramolecular organization is expected to differ significantly from the classical micelle. Its organization is investigated with experimental methods and molecular dynamics simulations (MDS). Although the linear length of a single biotin‐CMG‐DOPE molecule is 9.5 nm, the size of the dominant supramer globule is only 14.6 nm. Investigations found that while the DOPE tails form a hydrophobic core, the polar CMG spacer folds back upon itself and predominantly places the biotin reside inside the globule or planar layer. MDS demonstrates that <10 % of biotin residues on the highly water dispersible globules and only 1 % of biotin residues in layer coatings are in an linear conformation and exposing biotin into the aqueous medium. This explains why in biotin‐CMG‐DOPE apolar biotin residues both in water dispersible globules and coatings on solid surfaces are still capable of interacting with streptavidin. Binding cells together: Gemini amphiphile biotin‐CMG‐DOPE when coated on a surface forms a monolayer where quite non‐polar biotin residues are hidden in the hydrophobic DOPE zone, however ∼1 % of biotins are able to dynamically pop‐up and, therefore, bind to streptavidin.

• Publisher: John Wiley & Sons, Inc,John Wiley and Sons Inc,Wiley-VCH
• Subject: amphiphiles / Aqueous solutions / Biotin / Cluster analysis / Coatings / Dispersion / function-spacer-lipid / Globules / Hydrophobicity / Lipids / Micelles / Microscopy / Molecular dynamics / molecular dynamics simulations / Residues / Simulation / Solid surfaces / Sulfur / supramers