title: Electron-deficient alkynes as cleavable reagents for the modification of cysteine-containing peptides in aqueous medium.
abstract: An efficient method has been developed for the chemoselective cysteine modification of unprotected peptides and proteins in aqueous media through the formation of a vinyl sulfide linkage by using electron-deficient alkynes, including alkynoic amides, esters and alkynones. The terminal alkynone-modified peptides could be converted back into the unmodified peptides (81% isolated yield) by adding thiols under mild conditions. The usefulness of this thiol-assisted cleavage of the vinyl sulfide linkage in peptides has been exemplified by the enrichment of a cysteine-containing peptide (71% recovery) from a mixture of cysteine-containing and non-cysteine-containing peptides.
authors.affiliation: Department of Chemistry and Open Laboratory of Chemical Biology, Institute of Molecular Technology for Drug Discovery and Synthesis, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Hoi-Yan
authors.initials: HY
authors.lastname: Shiu
authors.forename: Tak-Chung
authors.initials: TC
authors.lastname: Chan
authors.forename: Chi-Ming
authors.initials: CM
authors.lastname: Ho
authors.forename: Yungen
authors.initials: Y
authors.lastname: Liu
authors.forename: Man-Kin
authors.initials: MK
authors.lastname: Wong
authors.forename: Chi-Ming
authors.initials: CM
authors.lastname: Che
mesh_terms: D000418:Albumins / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D004583:Electrons; D008024:Ligands; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D014753:Vinyl Compounds / Q000737:chemistry
chemical_list: D000418:Albumins; D000480:Alkynes; D008024:Ligands; D010455:Peptides; D013438:Sulfhydryl Compounds; D013440:Sulfides; D014753:Vinyl Compounds; D003545:Cysteine