Mikrobiyal amiloitlerin fonksiyonel biyomalzeme olarak kullanılması

Amyloids are fibrillar aggregations of proteins, dominated by β-sheets in the structure. They have high mechanical strength and rigidity that provides resistance to physical and chemical stress. In addition, amyloids can be easily functionalized with peptide groups for desired applications. These properties make them suitable candidates for biomaterial applications. Binding behavior of curli based amyloids on medically relevant surfaces are critical for their utilization controllable biomaterials. Furthermore, functionalization tor curli fibers too enhance their binding kinetics to surfaces and to organisms may hold great potentials for their desired applications as biomaterials. In this thesis, we characterized the binding kinetics of CsgA and CsgB curli proteins on silica, gold and hydroxyapatite surfaces to precisely control their surface adhesion. We showed that according to the physicochemical properties of surfaces, CsgA and CsgB displayed different binding behavior. Second, we hypothesized that glycosylation could enhance surface adhesiveness of curli fibers. For this purpose, TasA protein is engineered to obtain a glycosylation site and depicted that glycosylation increased adhesiveness of TasA fibers to gold surfaces. Finally, we functionalized CsgA curli fibers with RGD peptide to increase adhesiveness to living cells. Our results demonstrated that RGD peptide addition cause a significant increase in the number of cells adhered onto coated surfaces. In conclusion, amyloid proteins can serve as superior biomaterials with desired functionalities. Physicochemical properties of surfaces and proteins can have essential impacts on their interaction. In order to diversify those properties, amyloid fibers can be easily functionalized for specific purposes such as improved surface and cell adhesion. Functionalization with different peptide groups can extend their application capacity as superior biomaterials.