Fabrication of nanofibers with uniform morphology by self-assembly of designed peptides.
Fabrication of controlled peptide nanofibers with homogeneous morphology has been demonstrated. Amphiphilic beta-sheet peptides were designed as sequences of Pro-Lys-X(1)-Lys-X(2)-X(2)-Glu-X(1)-Glu-Pro. X(1) and X(2) were hydrophobic residues selected from Phe, Ile, Val, or Tyr. The peptide FI (X(1)=Phe; X(2)=Ile) self-assemble into straight fibers with 80-120 nm widths and clear edges, as examined by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The fiber formation is performed in a hierarchical manner: beta-sheet peptides form a protofibril, the protofibrils assemble side-by-side to form a ribbon, and the ribbons then coil in a left-handed fashion to make up a straight fiber. These type of fibers are formed from peptides possessing hydrophobic aromatic Phe residue(s). Furthermore, a peptide with Ala residues at both N and C termini does not form fibers (100 nm scale) with clear edges; this causes random aggregation of small pieces of fibers instead. Thus, the combination of unique amphiphilic sequences and terminal Pro residues determine the fiber morphology.
Matsumura
Sachiko
S
Ecology Research Laboratory, Corporate Research, Laboratory, Fuji Xerox Co. Ltd., 430 Sakai, Nakai-machi, Ashigarakami-gun, Kanagawa 259-0157, Japan.
Uemura
Shinobu
S
Mihara
Hisakazu
H
D000596:Amino Acids / Q000737:chemistry; D002942:Circular Dichroism / Q000379:methods; D036103:Nanotechnology; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D017433:Protein Structure, Secondary
D000596:Amino Acids; D010455:Peptides