11.01.2013 - Researches have constructed the first molecular machine that can produce peptides of defined sequences in milligram quantities.
The group of Bartosz Lewandowski from University of Manchester have taken another step toward the creation of a synthetic machine that performs the duties of a ribosome, which builds proteins in living organisms by joining amino acids together. As reported in Science, they have designed an artificial small-molecule machine that travels along a molecular strand, picking up amino acids that block its path, to synthesise a peptide in a sequence-specific manner.
The chemical structure is based on a rotaxane, a molecular ring threaded onto a molecular axle. The ring carries a thiolate group that iteratively removes amino acids in order from the strand and transfers them to a peptide-elongation site through native chemical ligation. The synthesis was demonstrated with ~1018 molecular machines acting in parallel; this process generated milligram quantities of a peptide with a single sequence confirmed by tandem mass spectrometry.
The study demonstrates that, in principle, small artificial molecular machines can be designed to perform such tasks autonomously. However, their machine lacked performance. In the current lab setting it only joined 3 amino acids together.