Proteins have emerged as a very attractive chemistry for the development of new materials, ranging from elastomers to biocatalysts to photonics to biomaterials. The application of synthetic biology at the interface of polymer science enables their design and engineering into such a wide variety of structures by using genetic engineering to control primary sequence and therefore impact all other hierarchical levels of structure. However, compared with the vast size of design space for protein materials, only a small number have been extensively explored. Originally, the limitation was on the production of genes encoding for different materials, which were often difficult to synthesize due to their large sizes and highly repetitive nature. With advances in gene synthesis, the limitation has moved to the ability to effectively express, purify, and test a large number of materials.
Unlike the engineering of enzymes or molecular binders, protein materials only demonstrate useful function in a purified state, posing new challenges for increasing throughput in this area of synthetic biology. Here, we talk about several different perspectives on this challenge. First, we examine methods for the simultaneous purification of hundreds of different protein materials using elastin-like protein tag technology originally developed by Chilkoti. With careful engineering of the system, combined with key advances in ELP thermodynamics that eliminate steps that are traditionally difficult or expensive to execute in high throughput, we are able to show the purification of materials in a series of well plates and demonstrate their effective evaluation.
Second, using the Opentrons low cost, open-source automation platform, we have developed methods to automate key steps and assays in clonal design, selection, and protein evaluation. While strain engineering is often a key step in industrial protein development, this is rarely performed in academic protein material design, potentially introducing a key bottleneck in materials yield. By using different optical designs, the need for integrating a plate reader with the automated system can be eliminated for many assays, providing an extremely low-cost and widely accessible platform that can increase throughput and improve access by the community to protein materials engineering.