21ENGBIO - Peptide excision, replacement and ligation (PERL) as a new strategy for protein engineering

在这个项目中，我们将开发一种全新的方法来重新设计蛋白质的基本结构。蛋白质工程是一种广泛应用于生物制药生产、活细胞过程研究和复杂材料合成的方法。蛋白质是由氨基酸的长聚合物组成的，这些氨基酸折叠起来形成复杂的三维形状。目前可以做出的大多数改变都是简单地添加到这些粒子的表面。打个比方，这些分子相当于重新粉刷汽车或添加新的轮胎轮辋。在蛋白质第一次制造之前（实际上是在蛋白质离开工厂之前），可以通过编辑蛋白质来对蛋白质的形状和结构进行更大的改变，但最终这些修饰必须由与原始蛋白质相同的材料进行，因此目前根本无法进行一些修饰。目前不可能做到的是，一旦蛋白质被制造出来，就对其进行大规模修改；去除已完成的、折叠的蛋白质中的一个元素，用新的部分代替，同时保留功能性蛋白质。在这个项目中，我们正在寻求做到这一点：我们将开发方法来执行分子等效将汽车变成敞篷车或切换引擎！基于我们实验室最近开发的一些重新连接蛋白质部分的技术，我们将开发一种方法，最终使我们能够移除一部分蛋白质，并用不同材料制成的替代部分取而代之，这些部分无法使用细胞机器插入。

In this project, we will develop a completely new way to re-engineer the basic structure of proteins. Engineering of proteins is a widely-used approach for the production of biopharmaceuticals, for the study of processes in the living cell and for the synthesis of complex materials. Proteins are formed of long polymers of amino-acids which fold up to form complex three-dimensional shapes. The majority of changes that can currently be made are simple additions to the surface of these particles. To use an analogy, these are the molecular equivalent of repainting a car or adding new tire rims. Larger changes to the shape and structure of the protein can be made by editing the protein before it is first made (effectively before it leaves the factory) but ultimately these modifications must be made of the same materials as the original protein and so some modifications are simply inaccessible at the moment.What it is not currently possible to do is to make large modifications to the protein once it has been made; to remove an element of the finished, folded protein and replace it with a new part while retaining a functional protein. In this project, we are seeking to do just that: we will develop methods to carry out the molecular equivalent of turning a car into a convertible or switching out the engine! Based on some recently developed technology in our laboratory to rejoin the protein parts, we will develop a method that will ultimately allow us to remove a part of the protein and replace it with alternative parts made from different materials that cannot be inserted using the machinery of the cell.