title: Controlled peptide-protein conjugation by means of 3-nitro-2-pyridinesulfenyl protection-activation.
abstract: The disulfide bond in S-3-nitro-2-pyridinesulfenyl (S-Npys) compounds is stable towards the acid treatment used in solid-phase peptide synthesis, yet the liability of S-Npys-peptides towards nucleophiles enables the conjugation to proteins to proceed under mild conditions. Thus Boc-Cys(Npys)-OH was coupled as N-terminal residue to a resin-linked peptide chain. After deprotection and cleavage from the resin the Npys-cysteinylpeptide was attached to a properly functionalized protein by reaction with a mercapto group. The amount of peptide conjugated to the protein was determined by measuring the amount of 3-nitro-2-thiopyridone liberated. The cysteinylpeptide which was detached from the protein by reduction of the disulfide bond was shown to be identical with the product obtained by reduction of the Npys-cysteinylpeptide.
authors.affiliation: Department of Medical Microbiology, State University of Groningen, The Netherlands.
authors.forename: J W
authors.initials: JW
authors.lastname: Drijfhout
authors.forename: E W
authors.initials: EW
authors.lastname: Perdijk
authors.forename: W J
authors.initials: WJ
authors.lastname: Weijer
authors.forename: W
authors.initials: W
authors.lastname: Bloemhoff
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D003545:Cysteine / Q000031:analogs & derivatives; D004220:Disulfides; D008969:Molecular Sequence Data; D009574:Nitro Compounds; D010455:Peptides / Q000138:chemical synthesis*; D011506:Proteins / Q000138:chemical synthesis*; D011725:Pyridines; D012710:Serum Albumin, Bovine
chemical_list: D004220:Disulfides; D009574:Nitro Compounds; D010455:Peptides; D011506:Proteins; D011725:Pyridines; D012710:Serum Albumin, Bovine; C050518:t-butyloxycarbonyl-(S-(3-nitro-2-pyridinesulfenyl))cysteine; D003545:Cysteine