Chemical mimicry: hierarchical 1D TiO2@ZrO2 core-shell structures reminiscent of sponge spicules by the synergistic effect of silicatein-α and silintaphin-1

Langmuir. 2011 May 3;27(9):5464-71. doi: 10.1021/la200066q. Epub 2011 Apr 1.

Abstract

In nature, mineralization of hard tissues occurs due to the synergistic effect of components present in the organic matrix of these tissues, with templating and catalytic effects. In Suberites domuncula, a well-studied example of the class of demosponges, silica formation is mediated and templated by an axial proteinaceous filament with silicatein-α, one of the main components. But so far, the effect of other organic constituents from the proteinaceous filament on the catalytic effect of silicatein-α has not been studied in detail. Here we describe the synthesis of core-shell TiO(2)@SiO(2) and TiO(2)@ZrO(2) nanofibers via grafting of silicatein-α onto a TiO(2) nanowire backbone followed by a coassembly of silintaphin-1 through its specifically interacting domains. We show for the first time a linker-free, one-step funtionalization of metal oxides with silicatein-α using glutamate tag. In the presence of silintaphin-1 silicatein-α facilitates the formation of a dense layer of SiO(2) or ZrO(2) on the TiO(2)@protein backbone template. The immobilization of silicatein-α onto TiO(2) probes was characterized by atomic force microscopy (AFM), optical light microscopy, and high-resolution transmission electron microscopy (HRTEM). The coassembly of silicatein-α and silintaphin-1 may contribute to biomimetic approaches that pursue a controlled formation of patterned biosilica-based biomaterials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomimetic Materials / chemistry*
  • Cathepsins / chemistry*
  • Enzymes, Immobilized / chemistry
  • Glutamic Acid / chemistry
  • Nanowires / chemistry
  • Suberites / chemistry*
  • Titanium / chemistry*
  • Zirconium / chemistry*

Substances

  • Enzymes, Immobilized
  • silicatein alpha
  • titanium dioxide
  • Glutamic Acid
  • Zirconium
  • Titanium
  • Cathepsins
  • zirconium oxide