A scalable method to purify reflectins from inclusion bodies

Structural proteins are an attractive inspiration for functional biobased materials. In nature, cephalopods skin colour modulation is related to the dynamic self-assembly of a family of structural proteins known as reflectins. To fully reach their potential as engineered bio-based materials, reflectins need to be produced by biotechnological means. One of the challenges is associated with establishing and optimizing reflectin purification processes to achieve the highest yield and productivity. Here, we studied purification strategies for two reflectin sequences from different organisms which were recombinantly expressed in a bacterial host at laboratory scale. Reflectins purification was then assessed by two chromatographic and one non-chromatographic methods. Methods were compared considering final purity and yield, productivity, cost and sustainability. The non-chromatographic method based on inclusion bodies washing presented the most promising results (protein purity > 90% and purification yields up to 88%). Our results contribute to define bioprocessing strategies to address the vision of biodegradable and sustainable protein-based materials.