1 research outputs found
Diatom Mimics: Directing the Formation of Biosilica Nanoparticles by Controlled Folding of Lysine-Leucine Peptides
Silaffins, long chain polyamines,
and other biomolecules found
in diatoms are involved in the assembly of a large number of silica
nanostructures under mild, ambient conditions. Nanofabrication researchers
have sought to mimic the diatom’s biosilica production capabilities
by engineering proteins to resemble aspects of naturally occurring
biomolecules. Such mimics can produce monodisperse biosilica nanospheres,
but in vitro production of the variety of intricate biosilica nanostructures
that compose the diatom frustule is not yet possible. In this study
we demonstrate how LK peptides, composed solely of lysine (K) and
leucine (L) amino acids arranged with varying hydrophobic periodicities,
initiate the formation of different biosilica nanostructures in vitro.
When L and K residues are arranged with a periodicity of 3.5 the α-helical
form of the LK peptide produces monodisperse biosilica nanospheres.
However, when the LK periodicity is changed to 3.0, corresponding
to a 3<sub>10</sub> helix, the morphology of the nanoparticles changes
to elongated rod-like structures. β-strand LK peptides with
a periodicity of 2.0 induce wire-like silica morphologies. This study
illustrates how the morphology of biosilica can be changed simply
by varying the periodicity of polar and nonpolar amino acids