Adding New Covalent Bonds to Proteins in Live Cells

 描述（由申请人提供）：蛋白质是生物学的基本组成部分和主力。蛋白质的一个基本限制是它们通过侧链共价键合的不足。这项应用将通过在活细胞中的蛋白质中引入新的共价键来打破这一天然屏障。该方法的原理是使用一种新的氨基酸与蛋白质中的天然氨基酸残基反应。然而，对生物活性、遗传编码和键形成的特异性的矛盾要求带来了巨大的挑战。我们的假设和创新是使新的氨基酸只有在它们接近时才能与目标天然氨基酸反应，从而允许在活细胞中的蛋白质中建立新的共价键。将开发适合于在生理条件下进行此类反应的新化学。已鉴定的化学功能将通过活细胞中的蛋白质翻译以新氨基酸的形式安装到蛋白质中。使用这种新的共价键合策略，我们将在蛋白质上建立光敏纳米桥，作为一种通用方法来光学调节蛋白质功能，用于细胞和体内的非侵入性研究。从长远来看，我们将进一步开发这些新的共价键，用于研究各种疾病中涉及的蛋白质网络和蛋白质-核酸相互作用，并用于产生新的蛋白质疗法。该项目的成功将通过利用天然蛋白质无法获得的新共价键，为研究和工程蛋白质和生物过程带来新的维度，从根本上影响基础生物学研究，生物技术，生物治疗和合成生物学。

 DESCRIPTION (provided by applicant): Proteins are basic building blocks and workhorses of biology. A fundamental limitation of proteins is their inadequacy in covalent bonding via side chains. This application will break this natural barrier by genetically introducing new covalent bonds into proteins in live cells. The principle of the approach is to use a novel amino acid to react with natural amino acid residues in proteins. However, huge challenges are imposed by the contradictory demands on bioreactivity, genetic encoding, and specificity of bond formation. Our hypothesis and innovation is to enable the new amino acid to react with the target natural amino acid only when they are in proximity, thus permitting building the new covalent bond in proteins in live cells. New chemistries suitable for such reactions under physiological conditions will be developed. The identified chemical functionality will be installed into proteins in the format of new amino acids through protein translation in live cells. Using this new covalent bonding strategy, we will build light-sensitive nano-bridges onto proteins as a general method to optically regulate protein function for noninvasive studies in cells and in vivo. In the long run, e will further develop these new covalent bonds for studying protein networks and protein-nucleic acid interactions involved in various diseases and for generating new protein therapeutics. The success of this project will lead to a new dimension for researching and engineering proteins and biological processes by harnessing the new covalent linkages inaccessible to natural proteins, fundamentally impacting basic biological studies, biotechnology, biotherapeutics, and synthetic biology.