title: Acetylation dictates the morphology of nanophase biosilica precipitated by a 14-amino acid leucine-lysine peptide.
abstract: N-terminal acetylation is a commonly used modification technique for synthetic peptides, mostly applied for reasons of enhanced stability, and in many cases regarded as inconsequential. In engineered biosilification - the controlled deposition of silica for nanotechnology applications by designed peptides - charged groups often play a deciding role. Here we report that changing the charge by acetylation of a 14-amino acid leucine-lysine (LK) peptide dramatically changes the morphology of precipitated biosilica; acetylated LK peptides produce nano-spheres, whereas nano-wires are precipitated by the same peptide in a non-acetylated form. By using interface-specific vibrational spectroscopy and coarse-grained molecular simulations, we show that this change in morphology is not the result of modified peptide-silica interactions, but rather caused by the stabilization of the hydrophobic core of peptide aggregates created by the removal of a peptide charge upon acetylation. These results should raise awareness of the potential impact of N-terminal modifications in peptide applications. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Lutz
authors.affiliation: University of Washington, 105 Benson Hall, WA, 98195-1750, USA.
authors.forename: Vance
authors.initials: V
authors.lastname: Jaeger
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany.
authors.forename: Mischa
authors.initials: M
authors.lastname: Bonn
authors.affiliation: University of Washington, 105 Benson Hall, WA, 98195-1750, USA.
authors.forename: Jim
authors.initials: J
authors.lastname: Pfaendtner
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Weidner
mesh_terms: D000107:Acetylation; D011232:Chemical Precipitation; D057927:Hydrophobic and Hydrophilic Interactions; D007930:Leucine / Q000737:chemistry*; D008239:Lysine / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D010455:Peptides / Q000737:chemistry*; D066329:Protein Aggregates; D012822:Silicon Dioxide / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D010455:Peptides; D066329:Protein Aggregates; D012822:Silicon Dioxide; D007930:Leucine; D008239:Lysine
keywords: acetylation; molecular dynamics; peptides; sum frequency generation