Sequence-Specific Peptide Synthesis by an Artificial Small-Molecule Machine

Abstract

Ribosomal Rotaxane? The ribosome is an extraordinarily sophisticated molecular machine, assembling amino acids into proteins based on the precise sequence dictated by messenger RNA. Lewandowski et al. (p. 189 ) have now taken a step toward the preparation of a stripped-down synthetic ribosome analog. Their machine comprises a rotaxane—a ring threaded on a rod—in which the ring bears a pendant thiol that can pluck amino acids off the rod; the terminal nitrogen then wraps around to form a peptide bond and liberate the thiol for further reaction. The system was able to link three amino acids in order from the preassembled rod.