Construction of Artificial TNF-Binding Proteins Based on the 10th Human Fibronectin Type III Domain Using Bacterial Display

Construction of antibody mimetics on the base of alternative scaffold proteins is a promising strategy for obtaining new products for medicine and biotechnology. The aim of our work was to optimize the cell display system for the 10th human fibronectin type III domain ( 10 Fn3) scaffold protein based on the AT877 autotransporter from Psychrobacter cryohalolentis K5 T and to construct new artificial TNF-binding proteins. We obtained a 10 Fn3 gene combinatorial library and screened it using the bacterial display method. After expression of the selected 10 Fn3 variants in Escherichia coli cells and analysis of their TNF-binding activity, we identified proteins that display high affinity for TNF and characterized their properties.