title: Peptide-templated gold nanocluster beacon as a sensitive, label-free sensor for protein post-translational modification enzymes.
abstract: Protein post-translational modifications (PTMs), which are chemical modifications and most often regulated by enzymes, play key roles in functional proteomics. Detection of PTM enzymes, thus, is critical in the study of cell functioning and development of diagnostic and therapeutic tools. Herein, we develop a simple peptide-templated method to direct rapid synthesis of highly fluorescent gold nanoclusters (AuNCs) and interrogate the effect of enzymatic modifications on their luminescence. A new finding is that enzymes are able to exert chemical modifications on the peptide-templated AuNCs and quench their fluorescence, which furnishes the development of a real-time and label-free sensing strategy for PTM enzymes. Two PTM enzymes, histone deacetylase 1 and protein kinase A, have been employed to demonstrate the feasibility of this enzyme-responsive fluorescent nanocluster beacon. The results reveal that the AuNCs' fluorescence can be dynamically decreased with increasing concentration of the enzymes, and subpicomolar detection limits are readily achieved for both enzymes. The developed strategy can thus offer a useful, label-free biosensor platform for the detection of protein-modifying enzymes and their inhibitors in biomedical applications.
authors.affiliation: State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University , Changsha, Hunan 410082, P. R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wen
authors.forename: Yi
authors.initials: Y
authors.lastname: Gu
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Tang
authors.forename: Ru-Qin
authors.initials: RQ
authors.lastname: Yu
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Jiang
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D056284:Histone Deacetylase 1 / Q000378:metabolism; D053761:Nanocomposites / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011499:Protein Processing, Post-Translational; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D010455:Peptides; D006046:Gold; D017868:Cyclic AMP-Dependent Protein Kinases; D056284:Histone Deacetylase 1