Oral Presentation 12th Australian Peptide Conference 2017

Diaminobenzoyl derivatives for constructing proteins: synthesis of N-terminal palmitoylated Sonic Hedgehog. (#250)

Juan Bautista Blanco-Canosa 1 , Judith Palà-Pujadas 2 , Fernando Albericio 1
  1. University of Barcelona, Barcelona, Spain
  2. Chemistry and molecular pharmacology, IRB Barcelona, Barcelona, Spain

3,4-Diaminobenzoyl derivatives, either 3,4-Diaminobenzoyl (Dbz) or 3-Amino-4-aminomethylbenzoyl (MeDbz), are utilized as C-terminal peptide thioester surrogates in the form of N-acylureas (Nbz and MeNbz) in native chemical ligation (NCL) [1, 2]. Under mild conditions, pH 7.0 and room temperature, both Nbz and MeNbz peptides undergo fast and chemoselective transthioesterification in the presence of thiol additives, yielding C-terminal peptide thioesters which are key components in the synthesis of proteins by NCL [3]. The o-aminoanilide derived from the Dbz moiety can be also activated in aqueous solution in unprotected peptides through the formation of benzotriazoles [4, 5], representing a further advantage since it allows to carry out sequential ligations in a kinetic controlled manner (KCL) [6]. Although the MeDbz can not undergo oxidation to generate benzotriazoles, we have developed a p-cyano-phenylcarbamate-MeDbz derivative (p-CN-PhCB-MeDbz) that smoothly rearranges through a MeNbz intermediate to afford thioester peptides. This improvement has enabled the realization of KCL using MeNbz (or Nbz) and p-CN-PhCB-MeDbz peptides. We have used these new approaches on the synthesis of N-terminal-palmitoylated C-terminal-biotinylated Sonic Hedgehog (SHh) protein analog. SHh activates the Hedgehog signaling cascade, an important developmental pathway that regulates organogenesis, neurodevelopment and stem cell proliferation, and which deregulation has been associated to neonatal malformations and carcinogenesis [7].

 

 

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