title: Left or Right: How Does Amino Acid Chirality Affect the Handedness of Nanostructures Self-Assembled from Short Amphiphilic Peptides?
abstract: Peptide and protein fibrils have attracted an enormous amount of interests due to their relevance to many neurodegenerative diseases and their potential applications in nanotechnology. Although twisted fibrils are regarded as the key intermediate structures of thick fibrils or bundles of fibrils, the factors determining their twisting tendency and their handedness development from the molecular to the supramolecular level are still poorly understood. In this study, we have designed three pairs of enantiomeric short amphiphilic peptides:LI3LK andDI3DK,LI3DK andDI3LK, andLaI3LK andDaI3DK, and investigated the chirality of their self-assembled nanofibrils through the combined use of atomic force microscopy (AFM), circular dichroism (CD) spectroscopy, scanning electron microscopy (SEM), and molecular dynamic (MD) simulations. The results indicated that the twisted handedness of the supramolecular nanofibrils was dictated by the chirality of the hydrophilic Lys head at the C-terminal, while their characteristic CD signals were determined by the chirality of hydrophobic Ile residues. MD simulations delineated the handedness development from molecular chirality to supramolecular handedness by showing that the β-sheets formed byLI3LK,LaI3LK, andDI3LK exhibited a propensity to twist in a left-handed direction, while the ones ofDI3DK,DaI3DK, andLI3DK in a right-handed twisting orientation.
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China) , 66 Changjiang West Road, Qingdao 266555, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China) , 66 Changjiang West Road, Qingdao 266555, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China) , 66 Changjiang West Road, Qingdao 266555, China.
authors.forename: Jiqian
authors.identifier: 0000-0002-7525-5943
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China) , 66 Changjiang West Road, Qingdao 266555, China.
authors.forename: Yurong
authors.identifier: 0000-0002-3727-158X
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China) , 66 Changjiang West Road, Qingdao 266555, China.
authors.forename: Hongchao
authors.initials: H
authors.lastname: Ma
authors.affiliation: Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester , Schuster Building, Manchester M13 9PL, U.K.
authors.forename: Jian R
authors.identifier: 0000-0001-5648-3564
authors.initials: JR
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China) , 66 Changjiang West Road, Qingdao 266555, China.
authors.forename: Hai
authors.identifier: 0000-0002-5796-4404
authors.initials: H
authors.lastname: Xu
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D049329:Nanostructures / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D010455:Peptides; D013501:Surface-Active Agents