title: Enabling N-to-C Ser/Thr Ligation for Convergent Protein Synthesis via Combining Chemical Ligation Approaches.
abstract: In this article, Ser/Thr ligation(on/off) has been realized to enable N-to-C successive peptide ligations using a salicylaldehyde semicarbazone (SAL(off)) group by in situ activation with pyruvic acid of the peptide SAL(off) ester into the peptide salicylaldehyde (SAL(on)) ester. In addition, a peptide with a C-terminal thioester and N-terminal Ser or Thr as the middle peptide segment can undergo one-pot Ser/Thr ligation and native chemical ligation in the N-to-C direction. The utility of this combined ligation strategy in the N-to-C direction has been showcased through the convergent assembly of a human cytokine protein sequence, GlcNAcylated interleukin-25.
authors.affiliation: Department of Chemistry, The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong , Pokfulam, Hong Kong SAR, China.
authors.forename: Chi Lung
authors.initials: CL
authors.lastname: Lee
authors.affiliation: Department of Chemistry, The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong , Pokfulam, Hong Kong SAR, China.
authors.forename: Han
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Chemistry, The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong , Pokfulam, Hong Kong SAR, China.
authors.forename: Clarence T T
authors.initials: CT
authors.lastname: Wong
authors.affiliation: Department of Chemistry, The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong , Pokfulam, Hong Kong SAR, China.
authors.forename: Hoi Yee
authors.initials: HY
authors.lastname: Chow
authors.affiliation: Department of Chemistry, The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong , Pokfulam, Hong Kong SAR, China.
authors.forename: Xuechen
authors.initials: X
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D002244:Carbon / Q000737:chemistry*; D060326:Chemistry Techniques, Synthetic; D003545:Cysteine / Q000737:chemistry*; D020381:Interleukin-17 / Q000138:chemical synthesis / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry*; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry; D011506:Proteins / Q000138:chemical synthesis* / Q000737:chemistry; D012694:Serine / Q000737:chemistry*
chemical_list: D020381:Interleukin-17; D009842:Oligopeptides; D011506:Proteins; D012694:Serine; D002244:Carbon; D003545:Cysteine; D009584:Nitrogen