非天然核酸在生物技术、生物医药、生物材料和半合成人工生命开发中具有重要而广泛的潜在应用价值，而高效的非天然核酸聚合酶是对非天然核酸进行应用的必要前提。现有的聚合酶突变株无法高效合成及PCR扩增大长度全修饰的非天然核酸，并且直接快速进化这些活性的聚合酶进化技术也比较缺乏。针对如上问题，本项目拟基于申请人聚合酶进化的前期工作(发表于Nature Chemistry，JACS等杂志)，采用新一代点击化学方法建立新型高效的噬菌体酶-底物共展示聚合酶进化技术，同时建立基于微乳液区室化系统的聚合酶非天然核酸PCR扩增活性直接进化技术，并结合高通量聚合酶筛选技术建立新的高效聚合酶进化平台。接着使用该平台对现有非天然核酸聚合酶突变株进行进一步进化，获得具有合成和扩增大长度全修饰非天然核酸的优异非天然核酸聚合酶。在此基础上，初步探索这些非天然核酸聚合酶突变株在获取非天然核酸适配体、生物材料和人工生命中的应用。

Unnatural nucleic acids have important and broad potential applications in biotechnology, biomedicine, biomaterials and development of semi-synthetic artificial life, and efficient polymerases for unnatural nucleic acids are essential for these applications. Current unnatural nucleic acid polymerase mutants are not able to efficiently synthesize unnatural nucleic acids with big length and amplify fully modified unnatural nucleic acids. Efficient polymerase evolution methods for these activities also need to be developed. In this project, based on our previous approach on polymerase evolution (published on Nature Chemistry, JACS, etc.), we plan to construct a new phage polymerase-substrate co-display technique for efficient polymerase evolution using new generation of click chemistry. A technique for directly evolving polymerase activity of PCR amplifying unnatural nucleic acids will also be constructed based on micro-emulsion compartment system. By combining these two techniques with high-throughput polymerase screening methods, we will build up a new efficient polymerase evolution platform. Using this platform, polymerase mutants will be further evolved to get polymerases with activities of synthesizing and amplifying fully modified unnatural nucleic acids. The applications of these polymerases in SELEX for unnatural nucleic acid aptamers and construction of novel biomaterials and artificial life composed of unnatural nucleic acids will also be explored.