Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
J Am Chem Soc. 2017 Aug 23;139(33):11427-11433. doi: 10.1021/jacs.7b03540. Epub 2017 Aug 10.
In an effort to expand the genetic alphabet and create semi-synthetic organisms (SSOs) that store and retrieve increased information, we have developed the unnatural base pairs (UBPs) dNaM and d5SICS or dTPT3 (dNaM-d5SICS and dNaM-dTPT3). The UBPs form based on hydrophobic and packing forces, as opposed to complementary hydrogen bonding, and while they are both retained within the in vivo environment of an Escherichia coli SSO, their development was based on structure-activity relationship (SAR) data generated in vitro. To address the likely possibility of different requirements of the in vivo environment, we screened 135 candidate UBPs for optimal performance in the SSO. Interestingly, we find that in vivo SARs differ from those collected in vitro, and most importantly, we identify four UBPs whose retention in the DNA of the SSO is higher than that of dNaM-dTPT3, which was previously the most promising UBP identified. The identification of these four UBPs further demonstrates that when optimized, hydrophobic and packing forces may be used to replace the complementary hydrogen bonding used by natural pairs and represents a significant advance in our continuing efforts to develop SSOs that store and retrieve more information than natural organisms.
为了扩展遗传密码子并创建能够存储和检索更多信息的半合成生物体（SSO），我们开发了非天然碱基对（UBP）dNaM 和 d5SICS 或 dTPT3（dNaM-d5SICS 和 dNaM-dTPT3）。UBP 是基于疏水性和堆积力形成的，而不是互补氢键，虽然它们都在大肠杆菌 SSO 的体内环境中保留，但它们的开发是基于体外产生的结构-活性关系（SAR）数据。为了解决体内环境可能存在不同要求的问题，我们筛选了 135 种候选 UBP，以在 SSO 中获得最佳性能。有趣的是，我们发现体内 SAR 与体外收集的 SAR 不同，最重要的是，我们鉴定出四种 UBP，其在 SSO 中的 DNA 保留率高于之前鉴定出的最有前途的 UBP dNaM-dTPT3。这四种 UBP 的鉴定进一步证明，当进行优化时，疏水性和堆积力可以替代天然碱基对使用的互补氢键，这是我们不断努力开发能够存储和检索比自然生物更多信息的 SSO 的重要进展。
