title: Labeling proteins with small molecules by site-specific posttranslational modification.
abstract: We report here the development of a general strategy for site-specific labeling of proteins with small molecules by posttranslational modification enzyme, phosphopantetheinyl transferase Sfp. The target proteins are expressed as fusions to the peptide carrier protein (PCP) excised from nonribosomal peptide synthetase, and Sfp catalyzes the covalent modification of a specific serine residue on PCP by the small molecule-phosphopantetheinyl conjugate. The labeling reaction proceeds with high specificity and efficiency, targeting PCP fusion proteins in the cell lysate. The PCP tag has been shown to be compatible with various proteins, and Sfp-catalyzed PCP modification, compatible with various small-molecule probes conjugated to coenzyme A, highlighting the potential of the PCP tag for site-specific protein labeling with small molecules.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology and Institute of Chemistry and Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Yin
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Li
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Walsh
mesh_terms: D001360:Avidin / Q000737:chemistry; D001665:Binding Sites; D001710:Biotin / Q000737:chemistry*; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D005453:Fluorescence; D015394:Molecular Structure; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013194:Staining and Labeling
chemical_list: D002352:Carrier Proteins; D011993:Recombinant Fusion Proteins; D001360:Avidin; D001710:Biotin; D010453:Peptide Synthases