Fibril Formation by an Amphipathic α-Helix-Forming Polypeptide Produced by Gene Engineering

書誌事項

タイトル別名
  • Fibril Formation by an Amphipathic .ALPHA.-Helix-Forming Polypeptide Produced by Gene Engineering.
  • Fibril Formation by an Amphipathic アルファ

この論文をさがす

抄録

The α3-peptide, which comprises three repeats of the seven-residue sequence Leu-Glu-Thr-Leu-Ala-Lys-Ala, was designed to form an amphipathic α-helix with a hydrophobic surface by Leu residues and a hydrophilic surface by Glu and Lys residues, thus yielding a coiled coil or a helical bundle structure through their association. The α3-peptide was produced by gene engineering using Escherichia coli. Association to a tetramer had been demonstrated by sedimentation equilibrium analysis in a previous study. In addition to tetramerization, electron microscopic observation revealed that the α3-peptide formed“fibrils”5 to 10nm in width in 10mM potassium phosphate/0.1M KCl (pH 6.0). By increasing the salt concentration, the α3-peptide formed much larger“fibers”assembled from many“filaments”running along the long axis, each of which was thinner and longer than those observed at lower salt concentration. Hydrophobic interaction is considered to be a main force responsible for forming the fibrous structure. However, the electrostatic features of the α3-peptide seem to affect fibril assembly, since the shape and size of the fibrous structure were altered by the ionic strength of the solution. To our knowledge, this is the first report to describe formation of a fibrous structure by a de novo designed α-helix-forming peptide, and thus the α3-peptide with its simple sequence is considered to be a potential model peptide for investigating the molecular mechanisms of fibril formation by peptides or proteins.

収録刊行物

被引用文献 (5)*注記

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ