FIBER DIFFRACTION STUDIES OF THE SILICATEIN PROTEIN FILAMENT

硅酸蛋白丝的纤维衍射研究

• 批准号: 7370519
• 负责人: DANIEL E MORSE
• 金额: $ 0.43万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7370519
• 关键词: FIBER; DIFFRACTION; STUDIES; SILICATEIN; PROTEIN

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We are proposing to perform fiber diffraction studies of the silicatein protein filament. These protein fibers (with dimensions of ~ 2 microns in diameter by 2 mm in length) are found occluded within the silica needle-like spicules made by the marine sponge Tethya aurantia. Our lab discovered that the filaments are composed of three related proteins that we named silicateins, which are members of the cathepsin/catalytic triad superfamily of hydrolases. In vitro, they catalyze and template the synthesis of silica, silicones, and semiconductors (such as gallium oxide, titanium dioxide, zinc oxide, etc.) from the corresponding molecular precursors. In addition, under ambient conditions, the resulting TiO2 and Ga2O3 products, formed in the presence of silicatein filaments at ambient temperature and pressure, are polymorphs whose formation usually requires extreme temperature, pH, and pressure conditions. Importantly, these coatings are nano-crystalline, suggesting the filament may be stabilizing and templating the inorganic products. Solving the fiber diffraction of the silicatein protein fibers is scientifically interesting for several reasons. First, they serve as templates to direct the nanostructures of the minerals (such as Ga2O3) they form by catalysis - thus representing the first instance of which we're aware of a class of truly structure-directing enzymes. We hope that by understanding the packing and periodicity of the proteins within the filament we will be able to describe the molecule determinants of templating and pseudo-epitaxial stabilization of the inorganic products. We have already seen evidence for a crystalline-like periodicity in the protein fibers (with low-resolution diffraction); the additional resolution provided by the synchrotron light-source should greatly expand our knowledge of the structure of the filament.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。我们建议进行纤维衍射研究的硅酸盐蛋白质丝。这些蛋白质纤维（直径约2微米，长度约2 mm）被发现封闭在由海洋海绵Tethya aurantia制成的二氧化硅针状物内。我们的实验室发现，这些纤维由三种相关的蛋白质组成，我们将其命名为silicateins，它们是水解酶的组织蛋白酶/催化三联体超家族的成员。在体外，它们可以催化和模板化二氧化硅、有机硅和半导体（如氧化镓、二氧化钛、氧化锌等）的合成。从相应的分子前体。此外，在环境条件下，在环境温度和压力下在硅酸盐纤维存在下形成的所得TiO 2和Ga 2 O 3产物是多晶型物，其形成通常需要极端的温度、pH和压力条件。重要的是，这些涂层是纳米晶体，这表明细丝可以稳定和模板化无机产物。解决硅酸盐蛋白质纤维的纤维衍射在科学上是有趣的，原因有几个。首先，它们作为模板来指导它们通过催化形成的矿物质（如Ga 2 O3）的纳米结构-因此代表了我们所知道的一类真正的结构指导酶的第一个实例。我们希望，通过了解包装和周期性的蛋白质内的细丝，我们将能够描述的模板和伪外延稳定的无机产品的分子决定因素。我们已经在蛋白质纤维中看到了类似晶体的周期性的证据（具有低分辨率衍射）;同步加速器光源提供的额外分辨率应该大大扩展我们对细丝结构的了解。