Spontaneous Vesicle Formation by Helical Glycopeptides in Water

Formation of gold nanoparticles in microreactor composed of helical peptide assembly in water

“…The apparent weight average molar mass, the association number, and the mean radius of gyration (R g ) were obtained as 3.8 × 10 7 , 6.3 × 10 3 , and 117 nm, respectively, from the Zimm-Berry plot. Using the obtained R h and R g values, the ratio of R h and R g was calculated to be 0.94, which suggests that the molecular assembly should take a vesicular structure, similarly to previous reports on peptosomes [12,13].…”

“…BPl24NAB was successfully dispersed in water by injection of BPl24NAB in an ethanol solution, which yielded stable self-assembly in a reproducible manner. We have reported preparation and characterization of peptosomes from two kinds of amphiphilic peptides with chain lengths of the hydrophobic helical peptides of 8 and 15 amino acid residues [12,13]. BPl24NAB contains a longer hydrophobic peptide of 25 amino acid residues, which generates a large dipole moment, over 80 debye.…”

“…The particle size may be controlled more precisely when the reductive reaction is carried out under milder conditions. In the present study, vesicles composed of helical peptides (peptosome) [12,13] were chosen as microreactors for Au 3+ reduction for the following reasons: (i) the size of gold particle may be limited by amount of Au 3+ incorporated in a small volume of inner aqueous phase of peptosome, (ii) aggregation of gold nanoparticles should be suppressed by encapsulation in peptosome, and (iii) reduction reactions may be facilitated in peptosomes if reducing agents in peptosomes are strengthened by an electrically negative atmosphere generated by the large dipole moments of helical peptides. A naphthyl group was chosen as a chromophore, which may help the reduction of Au 3+ .…”

Fully Hydrophobic Artificial Protein but Water Dispersible due to Large Dipole

“…[1][2][3][4][5] Helical peptide vesicle, peptosome, [6][7][8] is one of such examples, and has a unique property of highly ordered structure formed in the hydrophobic peptide layer. Formerly, hydrophobic helical peptides were connected with hydrophilic groups such as an ammonium group, 6 poly(ethyleneoxide), 7 or disaccharide 8 to bear the amphiphilicity in molecule. In the present study, three hydrophobic helical peptides are just connected together at the C terminals with a shape of three-arm helix, and the hydrophobic peptides were found to be dispersible in water.…”

“…All peptides were synthesized by the conventional liquid-phase method. Boc-(LAla-Aib) 4 -OBzl (BA8B) and Boc-(L-Ala-Aib) 8 -OBzl (BA16B) were synthesized by the methods in the literature. 10 All intermediates and final products were Figure 1.…”