A protein scaffold based on a consensus sequence of fibronectin type III (FN3) proteins, such as the tenth FN3 repeat from human fibronectin (human Tenascin), including isolated nucleic acids that encode a protein scaffold, vectors, host cells, and methods of making and using thereof. The protein scaffold molecules of the present invention exhibit enhanced thermal and chemical stability while presenting six modifiable loop domains which can be engineered to form a binding partner capable of binding to a target for applications in diagnostic and/or therapeutic compositions, methods and devices.
