Kapłon Tomasz M, Rymarczyk Grzegorz, Nocula-Ługowska Małgorzata, Jakób Michał, Kochman Marian, Lisowski Marek, Szewczuk Zbigniew, Ozyhar Andrzej
Department of Biochemistry, Faculty of Chemistry, Wrocław University of Technology, Wrocław, Poland.
Biomacromolecules. 2008 Aug;9(8):2118-25. doi: 10.1021/bm800135m. Epub 2008 Jul 18.
Fish otoliths composed of calcium carbonate and an organic matrix play a primary role in gravity sensing and the perception of sound. Starmaker (Stm) was the first protein found to be capable of influencing the process of biomineralization of otoliths. Stm dictates the shape, size, and selection of calcium carbonate polymorphs in a concentration-dependent manner. To facilitate exploration of the molecular basis of Stm function, we have developed and optimized a protocol for efficient expression and purification of the homogeneous nontagged Stm. The homogeneous nontagged Stm corresponds to its functional form, which is devoid of a signal peptide. A comprehensive biochemical and biophysical analysis of recombinant Stm, along with in silico examinations, indicate for the first time that Stm exhibits the properties of intrinsically disordered proteins. The functional significance of Stm having intrinsically disordered protein properties and its possible role in controlling the formation of otoliths is discussed.
由碳酸钙和有机基质组成的鱼类耳石在重力感应和声音感知中起主要作用。造星蛋白（Stm）是首个被发现能够影响耳石生物矿化过程的蛋白质。Stm以浓度依赖的方式决定碳酸钙多晶型物的形状、大小和选择。为便于探索Stm功能的分子基础，我们开发并优化了一种高效表达和纯化无标签均一化Stm的方案。无标签均一化Stm与其功能形式相对应，该功能形式没有信号肽。对重组Stm进行的全面生化和生物物理分析，以及计算机模拟研究首次表明，Stm具有内在无序蛋白的特性。本文讨论了Stm具有内在无序蛋白特性的功能意义及其在控制耳石形成中的可能作用。
