SBIR Phase II: Computer-Directed High Throughput Screening for Improved Enzymatic Activity

这个小企业创新研究（SBIR）二期项目的重点是开发一种使能技术，用于计算机指导的高通量筛选具有改进特性的蛋白质。Xencor的蛋白质设计自动化（PDA）预测了所有可能折叠成蛋白质三维结构的氨基酸序列。在这些序列中应该有分子具有“亲本”蛋白的结构和功能，以及额外的新特性，如增加的热稳定性或碱性最佳pH值。在第一阶段，该公司使用木聚糖酶作为模型蛋白解决了这种可能性。在针对酶的活性位点进行PDA重新设计后，该公司发现了比野生型蛋白更活跃的序列，并且具有不同的pH谱。这些结果是通过测试可能的110,592个序列中的260个获得的。在第二阶段，该公司将开发一种高通量分析系统，该系统将允许测试大多数预测序列。该研究还将改进PDA算法的静电功能，然后使用该版本的程序重新设计整个木聚糖酶分子，而不仅仅是活性位点，从而发现远离活性位点的影响蛋白质特性的突变。PDA技术提高了酶的效率，扩大了反应和工艺条件。主要市场包括聚合物制造商、从废物流中提取价值和食品加工。

This Small Business Innovation Research (SBIR) Phase II project focuses on the development of an enabling technology for computer- directed high-throughput screening of proteins with improved properties. Xencor's Protein Design Automation (PDA) predicts all the possible amino acid sequences that will fold into the three-dimensional structure of a protein. There should be molecules among those sequences that have the structure and function of the "parent "protein, together with additional novel properties such as increased thermo-stability or alkaline pH optima. In Phase I the company addressed this possibility using xylanase as a model protein. After targeting the active site of the enzyme for PDA re-design, the company found sequences that were more active than the wild-type protein and one that had a different pH profile. These results were achieved by testing only 260 of a possible 110,592 sequences. In Phase II the company will develop a high-throughput assay system that will allow testing the majority of the predicted sequences. The research will also improve electrostatic functions of the PDA algorithm, and then use this version of the program to re-design the entire xylanase molecule instead of just the active site, thereby finding mutations located away from the active site that effect the protein's characteristics.The PDA technology improves enzyme efficiency and expands the reactions and process conditions where they can be applied. Major markets include polymer manufacturers, value extraction from waste streams and food processing.