Design and Synthesis of a Protein Catenane This work was supported by The Skaggs Institute for Chemical Biology, The Sloan Foundation, and NIH-GM570132 (PED). We thank Dr. Songpong Deechongkit for assistance with the analytical ultracentrifuge and CD measurements.

In contrast to DNA, proteins with topologically linked backbone structures have not yet been observed in Nature. We have chemically synthesized a p53 protein catenane (see schematic representation) consisting of interlocking cyclic polypeptides to demonstrate that such structures are synthetically attainable and can significantly stabilize the folded conformation of a protein.