Fully Hydrophobic Artificial Protein but Water Dispersible due to Large Dipole

Abstract

ABSTRACT:Three-arm helices (TA16, TA8), in which three hydrophobic helical peptides were tethered together at their C-terminals, were synthesized, and self-assembling property in water was investigated. TA16 (m.w. = 5228) was dispersed easily in water even though this compound has no explicit hydrophilic moiety in the molecule. Dynamic light scattering measurement and transmission electron microscopy images of water dispersions of TA16 and TA8 revealed that spherical assemblies with diameter of 70 nm (TA16) and 100 nm (TA8) were formed. The central tertiary amine moiety in TA16 and TA8 should act as a hydrophilic part due to the convergent point of the three negatively polarized C-terminals of helices.

Hydrophobic Aib/Ala peptides solubilize in water through formation of supramolecular assemblies

“…Indeed, a few years ago Kimura and coworkers suggested the fascinating concept according to which molecules with a large dipole moment are intrinsically hydrophilic. 24 In any case, micellar aggregates of Z-(L-Ala) 3 -(Aib-L-Ala) 4 -OMe would have a diameter not larger than 5 nm, that is, approximately twice the length of the peptide helix (about 2 nm). Conversely, the aggregates observed by DLS and TEM exhibit a diameter about 10 times larger.…”

Molecular assembly formation of cyclic hexa‐β‐peptide composed of acetylated glycosamino acids

“…Further, these amide groups in the molecular assembly will be expected to align along tube axis and give rise to a large dipole moment. Molecular systems having a large dipole moment are our target for development of novel molecular devices 32–35. In the present article, we have extended the strategy to a larger cyclic peptide, cyclic hexapeptide of acetylated GA (Figure 1), and examined the conformation and the ability of tubular assembly formation of the large cyclic‐β‐peptide.…”

Self-Assemblies of Triskelion A2B-Type Amphiphilic Polypeptide Showing pH-Responsive Morphology Transformation

“…We have reported triskelion polypeptides composed of three fully hydrophobic helices self-assembled into vesicles, the diameters of which were dependent on the electric dipole intensities of the helices at the convergent point of the triskelion polypeptides. 12 The triskelion structure was also reported to form nanocages under the bioinspired design based on the clathrin protein. 18 In these reports, the same three molecular chains were connected to a central nitrogen atom as a convergent point of the molecules (A 3 -type triskelion).…”

“…Amphiphilic block copolymers self-assemble into various morphologies such as micelles, vesicles, fibers, and nanotubes. − Elucidation of the factors which govern the morphology and the assembly size is the key to applications of these molecular assemblies for drug delivery, nanoreactors, , and nanodevices . The factors hydrophilic/hydrophobic balance, , interactions of charges, dipole–dipole interactions, , and π–π stacking , have been intensively investigated. Furthermore, the self-assembly properties of amphiphilic molecules of various geometrical structures have been studied.…”

“…Furthermore, the self-assembly properties of amphiphilic molecules of various geometrical structures have been studied. We have reported triskelion polypeptides composed of three fully hydrophobic helices self-assembled into vesicles, the diameters of which were dependent on the electric dipole intensities of the helices at the convergent point of the triskelion polypeptides . The triskelion structure was also reported to form nanocages under the bioinspired design based on the clathrin protein .…”