Biomimetic synthesis of ordered silica structures mediated by block copolypeptides
Biomimetic synthesis of ordered silica structures mediated by block copolypeptides
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DOI：
10.1038/35002038
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发表时间：
2000-01-20
期刊：
影响因子：
64.8
通讯作者：
Deming, TJ
中科院分区：
文献类型：
--
作者：
Cha, JN;Stucky, GD;Deming, TJ
在硅藻和海绵等生物系统中，具有精确控制形态的固体二氧化硅结构的形成由蛋白质和多糖指导，并在中性pH和环境温度下在水中发生（1-4）。相比之下，实验室方法必须依赖于极端的pH条件和/或表面活性剂来诱导二氧化硅前体缩合成特定的形态或图案化结构（5-10），这种加工条件的对比和对最小化不利环境影响的良性合成方法的日益增长的需求激发了对材料科学中仿生方法的极大兴趣（4，5）。最近的证据表明，silicatein-一种在海绵Tethya aurantia的二氧化硅针状体中发现的蛋白质（11）-可以在环境条件下水解和缩合前体分子四乙氧基硅烷以形成具有受控形状的二氧化硅结构（12-14），在这方面似乎特别有前途，在这里，我们描述了合成的半胱氨酸-赖氨酸嵌段共聚肽，模仿silicatein的性质：共聚肽自组装成结构化的聚集体，水解四乙氧基硅烷，同时指导有序的二氧化硅形态的形成。我们发现，半胱氨酸巯基的氧化，这是已知的影响嵌段共聚肽（15）的组装，使我们能够产生不同的结构：硬二氧化硅球和明确的无定形二氧化硅柱分别使用完全还原和氧化形式的共聚物。
In biological systems such as diatoms and sponges, the formation of solid silica structures with precisely controlled morphologies is directed by proteins and polysaccharides and occurs in water at neutral:pH and ambient temperature(1-4). Laboratory methods, in contrast, have to rely on extreme pH conditions and/or surfactants to induce the condensation of silica precursors into specific morphologies or patterned structures(5-10), This contrast in processing conditions and the growing demand for benign synthesis methods that minimize adverse environmental effects have spurred much interest in biomimetic approaches in materials science(4,5), The recent demonstration that silicatein-a protein found in the silica spicules of the sponge Tethya aurantia(11)-can hydrolyse and condense the precursor molecule tetraethoxysilane to form silica structures with controlled shapes at ambient conditions(12-14) seems particularly promising in this context, Here we describe synthetic cysteine-lysine block copolypeptides that mimic the properties of silicatein: the copolypeptides self-assemble into structured aggregates that hydrolyse tetraethoxysilane while simultaneously directing the formation of ordered silica morphologies. We find that oxidation of the cysteine sulphydryl groups, which is known to affect the assembly of the block copolypeptide(15), allows us to produce different structures: hard silica spheres and well-defined columns of amorphous silica are produced using the fully reduced and the oxidized forms of the copolymer, respectively.