Denatured State Bias toward the Topology of Alpha-helical Folds

这个项目将研究线性氨基酸序列如何编码蛋白质的三维结构。折叠码具有根本的重要性，并且对于制药和生物技术行业具有明确的实用价值。解决折叠密码将最终允许具有所需结构和功能的蛋白质的可靠设计。破解折叠代码的主要障碍是代码是高度冗余的。两个几乎没有相似性的氨基酸序列可以产生具有相似三维形状的蛋白质。这个项目将测试的假设，短片段的蛋白质？蛋白质的氨基酸序列就像标点符号一样，使蛋白质链改变方向。把这些标点符号放在正确的地方就足以建立一个蛋白质？的形状。该项目还将为一名本科生和两名研究生提供广泛的生物化学和生物物理方法方面的培训。作为该项目的一部分，Bowler博士将与位于蒙大拿州米苏拉市中心的互动科学中心spectrUM Discovery Area合作。探索区提供实践活动，激发K-12学生对科学的兴奋。结合计算机图形和3D打印机生产的蛋白质物理模型，Bowler博士将为探索区开发教育模块，以展示蛋白质结构和功能之间的联系。 这项研究的重点将是一组包含两到四个α螺旋的小蛋白质。每种蛋白质都含有允许蛋白质链转动的序列。该项目将测试这样一个假设，即即使在破坏蛋白质结构的溶液条件下，转角序列也会使蛋白质的形状发生偏差。该项目将采用NMR和荧光方法，一种涉及组氨酸血红素环形成的热力学方法和计算机模拟来验证这一假设。这项研究还将测试蛋白质的形状是否可以通过将转角序列插入到已知形成单个长螺旋的42个残基的聚丙氨酸序列中来进化。最后，研究将测试蛋白质结构是否可以通过用多聚丙氨酸片段取代转角序列来进化。因此，这个项目将提供重要的新见解的作用，折叠代码中的转折序列。

This project will investigate how a linear sequence of amino acids encodes the three-dimensional structure of a protein. The folding code is of fundamental importance and has clear practical value for the pharmaceutical and biotech industries. Solving the folding code will ultimately allow reliable design of proteins with a desired structure and function. A primary barrier to cracking the folding code is that the code is highly redundant. Two amino acid sequences with little resemblance can yield proteins with similar three-dimensional shapes. This project will test the hypothesis that short segments of a protein?s amino acid sequence act like punctuation marks that bias the protein chain to change direction. Placing these punctuation marks in the right places is thus sufficient to establish a protein?s shape. This project will also provide training for one undergraduate student and two graduate students in a broad array of biochemical and biophysical methods. As part of this project, Dr. Bowler will work with the spectrUM Discovery Area, an interactive science center located in downtown Missoula, Montana. The Discovery Area provides hands-on activities to spark excitement about science in K-12 students. Combining computer graphics and physical models of proteins produced with a 3D printer, Dr. Bowler will develop educational modules for the Discovery Area to demonstrate the link between protein structure and function. The focus of this research will be a set of small proteins containing two to four alpha-helices in compact bundles. Each protein contains sequences that permit the protein chain to turn. This project will test the hypothesis that the turn sequences bias the shape of a protein even under solution conditions that disrupt protein structure. The project will employ NMR and fluorescence methods, a thermodynamic approach involving formation of histidine-heme loops and computer simulations to test this hypothesis. The research will also test whether protein shape can be evolved by inserting turn sequences into a 42 residue polyalanine sequence known to form a single long α-helix. Finally, the research will test whether protein structure can be devolved by replacing turn sequences with polyalanine segments. Thus, this project will provide important new insights into the role of turn sequences in the folding code.