N-methylcysteine-mediated total chemical synthesis of ubiquitin thioester.

ABSTRACT: Ubiquitin thioester is a key intermediate in the ubiquitylation of proteins and is formed enzymatically through the activation of alpha-COOH of ubiquitin in an ATP dependent manner using the E1 enzyme. The current methods used for the preparation of ubiquitin thioester rely on either the enzymatic machinery or on expressed protein ligation technology. In this article, we report a new chemical strategy, combining native chemical ligation and N-methylcysteine containing peptides, to chemically prepare ubiquitin thioester for the first time. The N-methylcysteine is utilized as an N-->S acyl transfer device, and in its protected form serves as a latent thioester functionality. This enabled us to trigger the formation of ubiquitin thioester subsequent to the assembly of the ubiquitin polypeptid

SUBMITTER: Erlich LA 

PROVIDER: S-EPMC3183995 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature