title: A colorimetric assay of protein kinase activity based on peptide-induced coagulation of gold nanorods.
abstract: We succeeded in applying gold nanorods (NRs) for the detection of protein kinase (PK) activity based on a substrate-induced coagulation mechanism. Because NRs have cationic surface charges due to surface-adsorbed cetyltrimethylammonium bromide, phosphorylated substrate peptides, which gain augmented anionic charges by phosphorylation, induce coagulation of the NRs, resulting in a red-to-blue color change of the corresponding NR dispersion. A large absorption coefficient of the NRs at the near-IR region enabled clear-cut detection of the peptide-induced coagulation. IC(50) values of several inhibitors of c-Src determined by the present assay are consistent with reported values.
authors.affiliation: Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan.
authors.forename: Hirotaro
authors.initials: H
authors.lastname: Kitazaki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Mori
authors.forename: Jeong-Hun
authors.initials: JH
authors.lastname: Kang
authors.forename: Takuro
authors.initials: T
authors.lastname: Niidome
authors.forename: Masaharu
authors.initials: M
authors.lastname: Murata
authors.forename: Makoto
authors.initials: M
authors.lastname: Hashizume
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Katayama
mesh_terms: D000327:Adsorption; D000838:Anions; D000081247:CSK Tyrosine-Protein Kinase; D002412:Cations; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D003116:Color; D003124:Colorimetry / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006801:Humans; D007211:Indoles / Q000737:chemistry; D007700:Kinetics; D043942:Nanotubes / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000737:chemistry; D011505:Protein-Tyrosine Kinases / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000737:chemistry; D011743:Pyrimidines / Q000737:chemistry; D055672:Static Electricity; D013449:Sulfonamides / Q000737:chemistry; D019061:src-Family Kinases
chemical_list: C412373:AG 1879; D000838:Anions; D002412:Cations; D002593:Cetrimonium Compounds; D007211:Indoles; D010455:Peptides; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; C416927:SU 6656; D013449:Sulfonamides; D006046:Gold; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; D000077286:Cetrimonium