title: Oxidative Deselenization of Selenocysteine: Applications for Programmed Ligation at Serine.
abstract: Despite the unique chemical properties of selenocysteine (Sec), ligation at Sec is an under-utilized methodology for protein synthesis. We describe herein an unprecedented protocol for the conversion of Sec to serine (Ser) in a single, high-yielding step. When coupled with ligation at Sec, this transformation provides a new approach to programmed ligations at Ser residues. This new reaction is compatible with a wide range of functionality, including the presence of unprotected amino acid side chains and appended glycans. The utility of the methodology is demonstrated in the rapid synthesis of complex glycopeptide fragments of the epithelial glycoproteins MUC5AC and MUC4 and through the total synthesis of the structured, cysteine (Cys)-free protein eglin C.
authors.affiliation: School of Chemistry, The University of Sydney, NSW 2006 (Australia) http://sydney.edu.au/science/chemistry/∼payne/index.html.
authors.forename: Lara R
authors.initials: LR
authors.lastname: Malins
authors.affiliation: School of Chemistry, The University of Sydney, NSW 2006 (Australia) http://sydney.edu.au/science/chemistry/∼payne/index.html.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Mitchell
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800 (Australia).
authors.forename: Sheena
authors.initials: S
authors.lastname: McGowan
authors.affiliation: School of Chemistry, The University of Sydney, NSW 2006 (Australia) http://sydney.edu.au/science/chemistry/∼payne/index.html. richard.payne@sydney.edu.au.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Payne
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003545:Cysteine / Q000737:chemistry*; D006020:Glycopeptides / Q000138:chemical synthesis* / Q000737:chemistry; D047709:Hirudo medicinalis / Q000737:chemistry; D006801:Humans; D008969:Molecular Sequence Data; D055271:Mucin 5AC / Q000138:chemical synthesis / Q000737:chemistry; D055264:Mucin-4 / Q000138:chemical synthesis / Q000737:chemistry; D010084:Oxidation-Reduction; D011506:Proteins / Q000138:chemical synthesis / Q000737:chemistry; D017279:Selenocysteine / Q000737:chemistry*
chemical_list: D006020:Glycopeptides; D055271:Mucin 5AC; D055264:Mucin-4; D011506:Proteins; C028656:eglin proteinase inhibitors; D017279:Selenocysteine; D003545:Cysteine
keywords: deselenization; glycopeptides; ligation; native chemical ligation; peptides