title: Short peptide tag for covalent protein labeling based on coiled coils.
abstract: To label proteins covalently, one faces a trade-off between labeling a protein specifically and using a small tag. Often one must compromise one parameter for the other or use additional components, such as an enzyme, to satisfy both requirements. Here, we report a new reaction that covalently labels proteins by using engineered coiled-coil peptides. Harnessing the concept of "proximity-induced reactivity", the 21-amino-acid three-heptad peptides CCE/CCK were modified with a nucleophilic cysteine and an α-chloroacetyl group at selected positions. When pairs of coiled coils associated, an irreversible covalent bond spontaneously formed between the peptides. The specificity of the cross-linking reaction was characterized, the probes were improved by making them bivalent, and the system was used to label a protein in vitro and receptors on the surface of mammalian cells.
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong , Shatin, Hong Kong SAR, China.
authors.forename: Jianpeng
authors.initials: J
authors.lastname: Wang
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Yu
authors.forename: Jiang
authors.initials: J
authors.lastname: Xia
mesh_terms: D000085:Acetates / Q000737:chemistry; D000818:Animals; D016466:CHO Cells; D002478:Cells, Cultured; D003412:Cricetulus; D003432:Cross-Linking Reagents / Q000138:chemical synthesis / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D049452:Green Fluorescent Proteins / Q000737:chemistry*; D057809:HEK293 Cells; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000085:Acetates; D003432:Cross-Linking Reagents; D010455:Peptides; D049452:Green Fluorescent Proteins; C006972:chloroacetic acid; D003545:Cysteine