title: Nepsilon-(thiaprolyl)-lysine as a handle for site-specific protein conjugation.
abstract: In this article, we introduce the use of a thiaproline-modified lysine side-chain [Lys(Thz)], as an unlockable handle that enables late-stage, site-selective modification of chemically synthesized proteins. The Lys(Thz) residue was incorporated into the murine chemokine RANTES to demonstrate its compatibility with Boc/Bzl solid phase peptide synthesis, native chemical ligation, and disulfide bond formation. After oxidative folding of the protein, the thiol was liberated under mild reaction conditions [0.2 M hydroxylamine (NH2OH) or O-methylhydroxylamine (MeONH2), pH 4] and was subsequently reacted with thiol-selective tags. This side chain protection strategy enables the use of readily available thiol-reactive probes for the modification of internally disulfide bonded proteins.
authors.affiliation: Department of Biochemistry, Cardiovascular Research Institute Maastricht, University Maastricht, The Netherlands.
authors.forename: Pieter
authors.initials: P
authors.lastname: Van de Vijver
authors.forename: Dennis
authors.initials: D
authors.lastname: Suylen
authors.forename: Anouk
authors.initials: A
authors.lastname: Dirksen
authors.forename: Philip E
authors.initials: PE
authors.lastname: Dawson
authors.forename: Tilman M
authors.initials: TM
authors.lastname: Hackeng
mesh_terms: D000818:Animals; D018946:Chemokine CCL5 / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry*; D008239:Lysine / Q000031:analogs & derivatives* / Q000737:chemistry*; D051379:Mice; D010084:Oxidation-Reduction; D017510:Protein Folding
chemical_list: C503460:Ccl5 protein, mouse; D018946:Chemokine CCL5; D004220:Disulfides; D008239:Lysine