NEW AMINO ACIDS FOR PROTEIN ENGINEERING

描述：蛋白质工程是设计新型液体的有力工具。 晶相、大分子表面阵列、可逆水凝胶和 用于组织再生和修复的人工细胞外基质。在……里面 体内微生物表达人工基因提供了一种准备 这种非天然蛋白质的产量很高。将目标结构编码为 一种人工基因，该基因在适当的微生物宿主中表达。 然而，体内蛋白质工程提出了一个挑战，因为 潜在的单体仅限于天然的蛋白质产生的氨基酸和 那些可以被激活和充电来转移RNA的类似物。Tirrell和 其他人成功地将蛋氨酸、异亮氨酸的类似物， 亮氨酸和苯丙氨酸通过其各自的作用 氨酰-tRNA合成酶。具有烯烃和乙炔官能团的类似物 已有研究表明，在细菌蛋白质中，基团可作为蛋氨酸的替代品 综合。这些官能团的加入创造了重要的新 化学衍生化的机会，扩大材料的范围 可以设计成基于蛋白质的聚合物的特性。例如, 烯烃复分解化学的最新进展导致了 催化高效环化反应的过渡金属卡宾的研究进展 含有烯烃侧链的多肽。这项建议的目的是 将快速计算模拟筛选方法和实验相结合-两者都在 体内和体外-寻找用于蛋白质工程的新氨基酸。 这种协作将导致快速高效地发现非自然生物 氨基酸类似物具有新的有用的功能，并将提供基础 用于构建具有所需性能的新型类蛋白质聚合物。这个 这里要使用的计算方法已经在设计中进行了测试 苯丙氨酸的类似物，并将扩展到Phe，Met， Ile、Leu和ValtRNA合成酶。

DESCRIPTION: Protein engineering is a powerful tool for design if novel liquid crystal phases, macromolecular surface arrays, reversible hydrogels, and artificial extracellular matrices for use in tissue regeneration and repair. In vivo microbial expression of artificial genes provides a means of preparing such non-natural proteins in high yields. The target structure is encoded into an artificial gene, and the gene is expressed in an appropriate microbial host. However, in vivo protein engineering poses a challenge in that the pool of potential monomers is restricted to the natural proteinogenic amino acids and those analogs that can be activated and charged to transfer RNAs. Tirrell and others have successfully incorporated analogs of methionine, isoleucine, leucine, and phenylalanine through the action of their respective aminoacyl-tRNA synthases. Analogs with olefinic and acetylenic functional groups have been shown to serve as methionine surrogates in bacterial protein synthesis. Incorporation of such functional groups creates important new opportunities for chemical derivatization, extending the range of materials properties that can be designed into protein-based polymers. For example, recent advances in the chemistry of olefin metathesis have led to the development of transition metal carbenes that catalyze efficient cyclization of peptides containing olefinic side chains. The objective of this proposal is to combine fast computational analog screening methods and experiments - both in vivo and in vitro - to find new amino acids for use in protein engineering. This collaboration will lead to fast and efficient discovery of non-natural amino acid analogs with new and useful functionality and will provide a basis for building novel protein-like polymers with desired properties. The computational methods to be used here have already been tested for design of analogs for phenylalanine and will be extended to new substrates for Phe, Met, Ile, Leu, and Val tRNA synthetases.