title: Development of new peptide-based receptor of fluorescent probe with femtomolar affinity for Cu(+) and detection of Cu(+) in Golgi apparatus.
abstract: Developing fluorescent probes for monitoring intracellular Cu(+) is important for human health and disease, whereas a few types of their receptors showing a limited range of binding affinities for Cu(+) have been reported. In the present study, we first report a novel peptide receptor of a fluorescent probe for the detection of Cu(+). Dansyl-labeled tripeptide probe (Dns-LLC) formed a 1:1 complex with Cu(+) and showed a turn-on fluorescent response to Cu(+) in aqueous buffered solutions. The dissociation constant of Dns-LLC for Cu(+) was determined to be 12 fM, showing that Dns-LLC had more potent binding affinity for Cu(+) than those of previously reported chemical probes for Cu(+). The binding mode study showed that the thiol group of the peptide receptor plays a critical role in potent binding with Cu(+) and the sulfonamide and amide groups of the probe might cooperate to form a complex with Cu(+). Dns-LLC detected Cu(+) selectively by a turn-on response among various biologically relevant metal ions, including Cu(2+) and Zn(2+). The selectivity of the peptide-based probe for Cu(+) was strongly dependent on the position of the cysteine residue in the peptide receptor part. The fluorescent peptide-based probe penetrated the living RKO cells and successfully detected Cu(+) in the Golgi apparatus in live cells by a turn-on response. Given the growing interest in imaging Cu(+) in live cells, a novel peptide receptor of Cu(+) will offer the potential for developing a variety of fluorescent probes for Cu(+) in the field of copper biochemistry.
authors.affiliation: Bioorganic Chemistry Laboratory, Center for Design and Applications of Molecular Catalysts, Department of Chemistry and Chemical Engineering, Inha University, Incheon 402-751, South Korea.
authors.forename: Kwan Ho
authors.initials: KH
authors.lastname: Jung
authors.affiliation: Department of Biomedical Sciences, Inha University College of Medicine, Incheon 402-751, South Korea; Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 402-751, South Korea.
authors.forename: Eun-Taex
authors.initials: ET
authors.lastname: Oh
authors.affiliation: Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 402-751, South Korea; Department of Microbiology, Inha Research Institute for Medical Science, College of Medicine, Inha University, Incheon 402-751, South Korea. Electronic address: park001@inha.ac.kr.
authors.forename: Heon Joo
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Bioorganic Chemistry Laboratory, Center for Design and Applications of Molecular Catalysts, Department of Chemistry and Chemical Engineering, Inha University, Incheon 402-751, South Korea. Electronic address: leekh@inha.ac.kr.
authors.forename: Keun-Hyeung
authors.initials: KH
authors.lastname: Lee
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D002412:Cations / Q000032:analysis; D002460:Cell Line; D045744:Cell Line, Tumor; D003300:Copper / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006056:Golgi Apparatus / Q000737:chemistry*; D006801:Humans; D061848:Optical Imaging / Q000379:methods*; D010455:Peptides / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D002412:Cations; D005456:Fluorescent Dyes; D010455:Peptides; D003300:Copper
keywords: Chemosensor; Copper; Cu(+); Fluorescent; Peptide; Probe