the macrocycle detached from the molecular track after the last amino acid stopper
was cleaved, and then the synthesized sequence-specific tetrapeptide was obtained
by acid hydrolysis.
The synthesis of polypeptides is an essential process in living organisms. In this
work, Leigh and co-workers used tandem mass spectrometry (MS/MS) to confirm
the product of the rotaxane-based molecular walker. The results indicated that the
amino acid sequence obtained from this novel synthesis strategy was identical with
an authentic sample synthesized by conventional methods. Furthermore, the authors
also demonstrated that there was no other by-product peptide detected, indicating
that the reactions are highly specific. Simultaneously, a control reaction was carried
out under the same conditions by using the non-threaded track and macrocycle that
showed no evidence for the formation of the same product under these conditions.
Thus, it can be concluded that the interlocked architecture of the molecular walker is
Fig. 7 The operation mode of the first artificial molecular production line for peptide synthesis [51]
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