The invention relates to a process for introducing a thiol group a to a carbonyl group in a side chain of a protected a-amino acid, said protected a-amino acid having protecting groups on both the α-amine group and the a-carboxyl group. The process comprises a) if the side chain contains a functional group comprising a heteroatom bearing a hydrogen atom, protecting said functional group; b) treating the protected amino acid with a base of sufficient strength to abstract a hydrogen atom a to the carbonyl group, so as to form an anion; c) treating the anion with a reagent of structure Pr-S-L in which L is a leaving group and Pr is a thiol-protecting group, so as to introduce a Pr-S- group a to the carbonyl group; and d) converting the Pr-S- group to an H-S-(thiol) group. This process may be used to prepare ligated peptides.
Accelerated Protein Synthesis via One-Pot Ligation-Deselenization Chemistry
作者:Nicholas J. Mitchell、Jessica Sayers、Sameer S. Kulkarni、Daniel Clayton、Anna M. Goldys、Jorge Ripoll-Rozada、Pedro José Barbosa Pereira、Bun Chan、Leo Radom、Richard J. Payne
DOI:10.1016/j.chempr.2017.04.003
日期:2017.5
Peptide ligation chemistry has revolutionized protein science by facilitating access to synthetic proteins. Here, we describe the development of additive-free ligation-deselenization chemistry at β-selenoaspartate and γ-selenoglutamate that enables the generation of native polypeptide products on unprecedented timescales. The deselenization step is chemoselective in the presence of unprotected selenocysteine
Peptide Ligations Accelerated by <i>N</i>-Terminal Aspartate and Glutamate Residues
作者:Gemma L. Thomas、Yves S. Y. Hsieh、Candy K. Y. Chun、Zheng-Li Cai、Jeffrey R. Reimers、Richard J. Payne
DOI:10.1021/ol2017356
日期:2011.9.16
A novel application of intramolecular base catalysis confers enhanced reaction rates for aminolysis ligations between peptide thioesters and peptides bearing N-terminal aspartate or glutamate residues. The broad scope of this process and its application in the total synthesis of the diabetes drug exenatide is demonstrated.