Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.
Department of Chemical Engineering, University of Washington, 105 Benson Hall, Seattle, WA, 98195-1750, USA.
Angew Chem Int Ed Engl. 2017 Jul 3;56(28):8277-8280. doi: 10.1002/anie.201702707. Epub 2017 Jun 13.
The silaffin peptide R5 is instrumental to the mineralization of silica cell walls of diatom organisms. The peptide is also widely employed in biotechnology, for example, in the encapsulation of enzymes and for fusion proteins in tissue regeneration. Despite its scientific and technological importance, the interfacial structure of R5 during silica precipitation remains poorly understood. We herein elucidate the conformation of the peptide in its active form within silica sheets by interface-specific vibrational spectroscopy in combination with molecular dynamics simulations. Contrary to previous solution-state NMR studies, our data confirm that R5 maintains a defined structure when interacting with extended silica sheets. We show that the entire amino acid sequence of R5 interacts with silica during silica formation, leading to the intercalation of silica into the assembled peptide film.
硅质体生物细胞壁的矿化作用离不开 silaffin 肽 R5 的参与。这种肽也被广泛应用于生物技术，例如酶的封装和组织再生中的融合蛋白。尽管它具有重要的科学和技术意义，但 R5 在硅沉淀过程中的界面结构仍知之甚少。我们通过界面特异性振动光谱结合分子动力学模拟阐明了肽在活性状态下在硅片中的构象。与之前的溶液态 NMR 研究相反，我们的数据证实，当与扩展的硅片相互作用时，R5 保持着确定的结构。我们表明，在硅形成过程中，R5 的整个氨基酸序列与硅相互作用，导致硅插入组装的肽膜中。
