Silica Synthesis Using Polypeptides

Various diblock copolypeptides were used to form sUica structures (Table 2). Cystein-lysine block copolypeptides were successfijl in fadhtating the sihca synthesis. 

Poly(diallyldi-methyl ammonium chloride) (PADA) 

It was postulated that these polypeptides self-assemble in solution and thus direct the formation of silica structures. These polypeptides were able to form spherical as well as pillar-like structures with TEOS precursor.  

and R5 peptides, three amino acid sequences found in the sillp protein (Fig. 3), were used in vitro to study the silica formation. It was revealed that these polypeptides also form silica upon the addition of TMOS solution. Another investigation made use of arginine-based surfactants to synthesize mesoporous silica.  

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It is notable that small peptides were retained on a cross-linked PEI column [37] but polypeptides over 20 residues were weakly retained or not at all. Possibly, small peptides were able to penetrate into the depth of the bonded phase while larger peptides could not. These packings were more useful for the separation of oligonucleotides, i.e. more acidic compounds. Lawson et al. [39] have shown the applicability of PEI-silicas for assessing the purity of precursor blocks, monitoring the chemical synthesis and isolating reaction products after synthesis. 

Polypeptide Synthesis and Analysis. Silica or controlled-pore glass supports treated with (chloromethyl)phenylethyltrimethoxysilane [68128-25-6] or its derivatives are replacing chloromethylated styrene—divinylbenzene (Merrifield resin) as supports in polypeptide synthesis. The silylated support reacts with the triethylammonium salt of a protected amino acid. Once the initial amino acid residue has been coupled to the support, a variety of peptide synthesis methods can be used (34). At the completion of synthesis, the anchored peptide is separated from the support with hydrogen bromide in acetic acid (see Protein engineering Proteins). 

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