Polycationic peptides from diatom biosilica that direct silica nanosphere formation.

@article{Krger1999PolycationicPF,
  title={Polycationic peptides from diatom biosilica that direct silica nanosphere formation.},
  author={Nils Kr{\"o}ger and Rainer Deutzmann and Manfred Sumper},
  journal={Science},
  year={1999},
  volume={286 5442},
  pages={
          1129-32
        }
}
Diatom cell walls are regarded as a paradigm for controlled production of nanostructured silica, but the mechanisms allowing biosilicification to proceed at ambient temperature at high rates have remained enigmatic. A set of polycationic peptides (called silaffins) isolated from diatom cell walls were shown to generate networks of silica nanospheres within seconds when added to a solution of silicic acid. Silaffins contain covalently modified lysine-lysine elements. The first lysine bears a… 

Biomimetic synthesis of silica nanospheres depends on the aggregation and phase separation of polyamines in aqueous solution

Long-chain polyamines extracted from the highly siliceous cell walls of diatoms are known to precipitate silica nanospheres from aqueous, silicic-acid containing solutions at near-neutral pH in

The Diatom Peptide R5 Fabricates Two-Dimensional Titanium Dioxide Nanosheets.

Diatoms use peptides based on the protein silaffin to fabricate their silica cell walls. To the interest of material scientists, silaffin peptides can also produce titanium dioxide nanoparticles.

The Structure of the Diatom Silaffin Peptide R5 within Freestanding Two-Dimensional Biosilica Sheets.

It is shown that the entire amino acid sequence of R5 interacts with silica during silica formation, leading to the intercalation of silica into the assembled peptide film, contradicting previous solution-state NMR studies.

POLYMERIC AMINES: ROLE IN BIOSILICIFICATON AND POTENTIAL IN NANOTECHNOLOGIES

Condensation of silicic acid was studied in the presence of poly(vinylamine) fractions (238-11000 units). The reaction results in soluble nanoparticles or composite precipitates depending on

Silacidins: highly acidic phosphopeptides from diatom shells assist in silica precipitation in vitro.

A new class of aspartate/glutamate-rich and serine phosphate rich peptides as constituents of biosilica produced by the diatom Thalassiosira pseudonana is described, known as silacidins due to their presence in silica and their acidic nature.

Biomimetic silica formation: analysis of the phosphate-induced self-assembly of polyamines.

Solid-state 31P NMR studies on phase-separated polyamines, synthetic silica precipitates, and diatom cell walls from the species Coscinodicus granii support the assumption of a phosphate-induced phase separation process taking place during cell wall formation.

Nanosilica formation at lipid membranes induced by silaffin peptides

Diatoms are unicellular eukaryotic algae found in fresh and marine water. Each cell is surrounded by an outer shell called a frustule that is composed of highly structured amorphous silica. Diatoms

Self-Assembly in Biosilicification and Biotemplated Silica Materials

A more recent strategy based on the integration of biological self-assembly as the driving force of silica nanoparticles organization offers new perspectives to elaborate highly-tunable, biofunctional nanocomposites.

Tailored synthetic polyamines for controlled biomimetic silica formation.

A synthetic route based on solid-phase peptide synthesis is described from which well-defined long-chain polyamines with different chain lengths, methylation patterns, and subunits can be obtained and may pave the way for better control of the formation of nanostructured silica under ambient conditions.
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