X-ray and Electron Diffraction Observations of Steric Zipper Interactions in Metal-Induced Peptide Cross-β Nanostructures

• DOI: 10.1021/jacs.3c04710
• Publication Date: 2023-07-12T12:28:35Z
• Authors: Eisuke Tsunekawa; Yusuke Otsubo; Yusuke Yamada; Akihito Ikeda; Naruhiko Adachi; Masato Kawasaki; Akira Takasu; Shinji Aramaki; Toshiya Senda; Sota Sato; Satoshi Yoshida; Makoto Fujita; Tomohisa Sawada
• Keywords: Zipper

The steric zipper is a common hydrophobic packing structure of peptide side chains that forms between two adjacent β-sheet layers in amyloid and related fibrils. Although previous studies have revealed fragments derived from native protein sequences exhibit structures, their de novo designs rarely been studied. Herein, structures were artificially constructed the crystalline state by metal-induced folding assembly tetrapeptide Boc-3pa-X1-3pa-X2-OMe (3pa: β-(3-pyridyl)-l-alanine; X1 X2: amino acids). Crystallographic types interdigitation contact, result class 1 geometry when X2 residues contain alkyl chains. Furthermore, 3 was also observed for first time among any reported zippers using with (X1, X2) = (Thr, Thr) (Phe, Leu). system could be extended to knob–hole-type pentapeptide sequence.