We investigated the silicification activity of hyperphosphorylated peptides in combination with long-chain polyamines (LCPA). The bioinspired in vitro silicification experiments with peptides containing different amounts of phosphorylated serines showed structure-activity dependence by altering the amount and morphology of the silica precipitate. Our study provides an explanation for the considerable metabolic role of diatoms in the synthesis of hyperphosphorylated poly-cationic peptides such as natSil-1A1. The efficient late-stage phosphorylation of peptides yielded a synthetic heptaphosphopeptide whose silicification properties resemble those of natSil-1A1. As opposed to this, unphosphorylated poly-cationic peptides or LCPA require concentrations above 1 mM for silicification. Hyperphosphorylated peptides showed a linear dependence between the amount of dissolved peptides and the amount of precipitated silica in the concentration range below 1 mM. Under mildly acidic conditions and short precipitation times, the concentration of the added LCPA determined the size of the silica spheres.

中文翻译：

---

磷酸肽在二氧化硅矿化中的作用。

我们研究了与长链多胺（LCPA）结合的高磷酸化肽的硅化活性。生物启发的体外硅化实验表明，通过改变二氧化硅沉淀物的数量和形态，可以使肽含有不同量的磷酸化丝氨酸，从而显示出结构活性的依赖性。我们的研究为硅藻在合成超磷酸化聚阳离子肽（如natSil-1A1）中的重要代谢作用提供了解释。肽的有效后期磷酸化产生了合成的七磷酸肽，其硅化性质类似于natSil-1A1的硅化性质。与此相反，未磷酸化的聚阳离子肽或LCPA要求硅化的浓度高于1 mM。在低于1 mM的浓度范围内，高磷酸化的肽在溶解的肽的量和沉淀的二氧化硅的量之间显示出线性关系。在弱酸性条件下和短的沉淀时间下，添加的LCPA的浓度决定了二氧化硅球的大小。