New and versatile chemical approaches for the synthesis of mRNA and tRNA

分子生物学的中心教条是“DNA制造RNA，制造蛋白质。”我们感兴趣的是拦截第二步“RNA制造蛋白质”的可能性。在这一步骤中需要两个不同的RNA分子，信使RNA(MRNA)和转移RNA(TRNA)；它们结合在一起，将DNA的四个字母代码转换为蛋白质的序列。原则上，这一过程可以由化学家操纵，他们可以通过自动化的固相方法组装RNA。这将使生产化学修饰的RNA成为可能，进而通过加入非天然的构建基团(氨基酸)来生产具有新的和改进的性质的修饰蛋白质。然而，制造所需的长的修饰的RNA链来实现这一点超出了目前基于固相合成的化学方法的范围。因此，我们将发展一种新的方法学，即固相合成RNA结合化学连接，将几条化学合成的RNA链连接在一起，制造出足够大的mRNA分子，这些分子既可以用作治疗分子，也可以用于制造有用的蛋白质。我们合成的信使核糖核酸(ChemRNA)将比生物产生的核糖核酸有许多优势。特别是，它可以非常大规模地制造，并有可能引入许多生物系统无法获得的外来化学修饰，以增强其稳定性，并提高其靶向体内特定器官的能力。这是一个重要的目标，因为生物化学衍生的信使核糖核酸在免疫治疗、传染病控制和癌症治疗中开始显示出希望。事实上，一些mRNAs甚至已经进入临床试验。然而，它们的发展受到修改它们以使其在人体内稳定的困难的限制。ChemRNA还可以与chem-tRNA结合使用，以制造目前的生化或生物方法无法制造的蛋白质。然后，可以利用试管中的化学进化来生产性能增强的新蛋白质，用于包括生物技术和合成生物学在内的许多领域。

The central dogma of molecular biology states that "DNA makes RNA makes proteins." We are interested in the possibility of intercepting the second step "RNA makes proteins." Two different RNA molecules, messenger RNA (mRNA) and transfer RNA (tRNA) are required in this step; they combine to convert the four letter code of DNA into the sequence of a protein. In principle this process could be manipulated by chemists who can assemble RNA by automated solid-phase methods. This would make it possible to produce chemically modified RNA and in turn modified proteins with new and improved properties by including unnatural building blocks (amino-acids). However, making the required long modified RNA strands to achieve this is beyond the scope of current chemical methods which are based on solid-phase synthesis. Therefore we will develop a new methodology, solid-phase synthesis of RNA combined with chemical ligation, to join together several chemically synthesised RNA strands in a chain to make mRNA molecules that are large enough to be used as therapeutic molecules and which can also be used to make useful proteins. Our synthetic mRNA (chemRNA) will have many advantages over biologically produced RNA. In particular it can be made on a very large scale, and it is possible to introduce many exotic chemical modifications that are not available to biological systems to enhance its stability and improve its ability to target particular organs in the body. This is an important objective because biochemically-derived, mRNA is starting to show promise in immunotherapy, infectious disease control and cancer therapy. Indeed, some mRNAs have even entered clinical trials. However, their development is limited by the difficulty in modifying them to make them stable in the human body. ChemRNA could also be used in combination with chem-tRNA to make proteins that cannot be made by current biochemical or biological methods. Chemical evolution in a test tube could then be used to produce new proteins with enhanced properties for use in many fields including biotechnology and synthetic biology.