title: A gold nanoparticles colorimetric assay for label-free detection of protein kinase activity based on phosphorylation protection against exopeptidase cleavage.
abstract: Protein kinases are significant regulators in the cell signaling pathways, and it is still greatly desirable to achieve simple and quick kinase detection. Herein, we present a novel colorimetric gold nanoparticles (AuNPs)/peptide platform for probing the activity and inhibition of protein kinases based on phosphorylation-induced suppression of carboxypeptidase Y (CPY) cleavage. This AuNPs/peptide platform can easily monitor the kinase activity by a UV-vis spectrometer or even by the naked eye. The feasibility of the method has been demonstrated by sensitive measurement of the cAMP-dependent protein kinase (PKA) activity with a low detection limit of 0.232 mU/µL and assessment of kinase inhibition by H-89 with an IC50 value of 18.13 nM. The assay was also successfully put into practice for the detection of kinase activity in cell lysate. Because of its label-free, homogenous and colorimetric merits, the proposed assay presents great potential in high-throughput screening for kinase-targeted drug discovery.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhou
authors.forename: Xiahong
authors.initials: X
authors.lastname: Xu
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: Zhou
authors.initials: Z
authors.lastname: Nie
authors.forename: Meng
authors.initials: M
authors.lastname: Qing
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods*; D020689:Exopeptidases / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D010766:Phosphorylation; D011494:Protein Kinases / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D006046:Gold; D011494:Protein Kinases; D020689:Exopeptidases
keywords: Carboxypeptidase Y; Cell lysate; Gold nanoparticles; Protein kinase; Protein phosphorylation