Stabilization of the fibrous structure of an alpha-helix-forming peptide by sequence reversal

作者：Kojima S^*; Kuriki Y; Yazaki K; Miura K

来源：Biochemical and Biophysical Research Communications, 2005, 331(2): 577-582.

DOI：10.1016/j.bbrc.2005.03.219

• alpha-helix
• circular dichroism spectra
• fiber formation
• fibrous structure
• sequence reversal
• transmission electron microscopy

The α 3-peptide, which comprises three repeats of the sequence Leu-Glu-Thr-Leu-Ala-Lys-Ala and forms an amphipathic of-helix, is unique among various α-helix-forming peptides in that it assembles into fibrous structures that can be observed by transmission electron microscopy. As part of our investigation of the structure-stability relationships of the α 3-peptide, we synthesized the α 3-peptide, whose amino acid sequence is the reverse of that of the α 3-peptide, and we investigated the effects of sequence reversal on α-helix stability and the formation of fibrous structures. Unexpectedly, the r3-peptide formed a more-stable α-helix and longer fibers than did the α 3-peptide. The stability of the r3-peptide helix decreased when the ionic strength or the buffer was increased and when the pH of the buffer was adjusted to 2 or 12. These results suggest that the r3-peptide underwent a "magnet-like" oligomerization and that an increase in the charge-distribution inequality may be the driving force for the formation of fibrous structures. © 2005 Elsevier Inc.

• 出版日期2005-6-3
• 单位河北医科大学