Acetylation dictates the morphology of nanophase biosilica precipitated by a 14-amino acid leucine-lysine peptide

作者：Lutz Helmut; Jaeger Vance; Bonn Mischa; Pfaendtner Jim; Weidner Tobias

来源：Journal of Peptide Science, 2017, 23(2): 141-147.

DOI：10.1002/psc.2960

• peptides
• sum frequency generation
• molecular dynamics
• acetylation

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.

• 出版日期2017-2