Biosilica formation peptide

The complex morphology of the nanopatterned siUca diatom cell walls has been found to be related to species-specific sets of polycationic peptides, so-called silaffins, which were isolated from diatom cell walls [82], The morphologies of precipitated sihca can be controlled by changing the chain lengths of the polyamines as well as by a synergistic action of long-chain polyamines and silaffins [83,84]. It has been proposed that the delicate pattern formation in diatom shells can be explained by phase separation of silica solutions in the presence of these polyamines [85]. Various linear synthetic analogs of the natural active polyamines in biosilica formation can accelerate the silicic acid condensation even more than the above mentioned... 

Kroger N, Deutzmann R, Sumper M (1999) Polycationic peptides from diatom biosilica that direct silica nanosphere formation. Science 286 1129-1132... 

It is well known that a variety of organisms are able to produce intricately patterned species-specific siliceous materials and that they are able to do so with great fidelity. In order to understand the role(s) that biomolecules play in the formation of nano- and micro-structured biosilica, organic material associated with biosilica has been isolated, identified and studied. To date, the main focus has been a variety of investigations of R5 (in both its modified and unmodified forms) and its ability to form silica in vitro. The R5 peptide is a nineteen amino acid sequence which corresponds with silaffin-lAi of the diatom Cylindrotheca fusiformis. In order to study the role of biomolecules in (bio)silicification, we have chosen to systematically study the silica forming ability of three peptides derived fi om the diatom C. fusiformis - namely, Rl, R2, and R5. The R1 peptide is a thirty three amino acid... 

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