title: Self-assembly of nanofiber with uniform width from wheel-type trigonal-beta-sheet-forming peptide.
abstract: A novel C3 symmetric peptide conjugate "Wheel-FKFE" consisting of three beta-sheet-forming peptides with wheel-like arrangement is developed, and the morphology of self-assembled peptide conjugates in aqueous solutions is observed at various pH. The CD spectra of Wheel-FKFE show the formation of beta-sheet structures in pH 6.9 phosphate buffer, whereas random structures are formed in aqueous HCl (pH 3.3) and NaOH (pH 11) solutions. In transmission electron microscopy, nanofibers with a uniform width of 3-4 nm and lengths of several micrometers are observed in pH 6.9 phosphate buffer, whereas nanorods with the width of several nanometers and the length of several tens of nanometers are observed for that of aqueous HCl (pH 3.3) and NaOH (pH 11) solutions. The uniform width (3-4 nm) of the fibers observed in neutral solution indicates formation of columnar self-assembly of Wheel-FKFEs. The fluorescence spectrum of polarity sensitive dye, sodium 8-anilino-1-naphthalenesulfonate (ANS), in the presence of Wheel-FKFE fibers revealed that the polarity inside the fibers corresponds to that of acetone, indicating that the internal space of the fibers possesses medium hydrophobic environment.
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Moto-oka 744, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Murasato
authors.forename: Kazunori
authors.initials: K
authors.lastname: Matsuura
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kimizuka
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D014227:Triazines / Q000138:chemical synthesis / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D010455:Peptides; D014227:Triazines; C528062:Wheel-FKFE; D014867:Water