Greek key jellyroll protein motif design: expression and characterization of a first-generation molecule

A protein designed de novo to fold into the Greek key jellyrollstructural motif has been studied. Theoretical analyses haveindicated that the designed sequence should adopt the ß-strandarrangement of the Greek key jellyroll rather than any otherarrangement. A synthetic gene was constructed and the proteinexpressed in Escherichia coli. Circular dichroism spectroscopyis consistent with the protein folding into the designed conformationand also suggests the presence of tertiary structure. Fluorescencespectroscopy showed the single tryptophan to be partially buried,while denaturation studies showed changes in fluorescence toprecede alterations in secondary structure.