title: Design, expression and characterization of a highly stable tetratricopeptide-based protein scaffold for phage display application.
abstract: Tetratricopeptide repeat (TPR) is a structural motif mediating variety of protein-protein interactions. It has a high potential to serve as a small, stable and robust, non-immunoglobulin ligand binding scaffold. In this study, we showed the consensus approach to design the novel protein called designed tetratricopeptide repeat (dTPR), composed of three repeated 34 amino-acid tetratricopeptide motifs. The designed sequence was efficiently overexpressed in E. coli and purified to homogeneity. Recombinant dTPR is monomeric in solution and preserves its secondary structure within the pH range from 2.0 to 11.0. Its denaturation temperature at pH 7.5 is extremely high (104.5°C) as determined by differential scanning calorimetry. At extreme pH values the protein is still very stable: denaturation temperature is 90.1°C at pH 2.0 and 60.4°C at pH 11. Chemical unfolding of the dTPR is a cooperative, two-state process both at pH 7.5 and 2.0. The free energy of denaturation in the absence of denaturant equals to 15.0 kcal/mol and 13.5 kcal/mol at pH 7.5 and 2.0, respectively. Efficient expression and extraordinary biophysical properties make dTPR a promising framework for a biotechnological application, such as generation of specific ligand- binding molecules.
authors.affiliation: Departament of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Wrocław, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Petters
authors.affiliation: Department of Protein Biotechnology, Faculty of Biotechnology, University of Wroclaw, Wrocław, Poland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Krowarsch
authors.affiliation: Departament of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Wrocław, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Otlewski
mesh_terms: D001435:Bacteriophages / Q000737:chemistry / Q000235:genetics; D061505:Cell Surface Display Techniques / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics; D020962:Heterotrimeric GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D011485:Protein Binding; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D054730:Protein Interaction Domains and Motifs / Q000235:genetics*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D020962:Heterotrimeric GTP-Binding Proteins