ABSTRACT
Proteins have been used as templates to stabilize fluorescent metal nanoclusters thus obtaining stable fluorescent structures, and their fluorescent properties being modulated by the type of protein employed. Designed consensus tetratricopeptide repeat (CTPR) proteins are suited candidates as templates for the stabilization of metal nanoclusters due to their modular structural and functional properties. Here, we have studied the ability of CTPR proteins to stabilize fluorescent gold nanoclusters giving rise to designed functional hybrid nanostructures. First, we have investigated the influence of the number of CTPR units, as well as the presence of cysteine residues in the CTPR protein, on the fluorescent properties of the protein-stabilized gold nanoclusters. Synthetic protocols to retain the protein structure and function have been developed, since the structural and functional integrity of the protein template is critical for further applications. Finally, as a proof-of-concept, a CTPR module with specific binding capabilities has been used to stabilize gold nanoclusters with positive results. Remarkably, the protein-stabilized gold nanocluster obtained combines both the fluorescence properties of the nanoclusters and the functional properties of the protein. The fluorescence changes in nanoclusters fluorescence have been successfully used as a sensor to detect when the specific ligand was recognized by the CTPR module.
Subject(s)
Adaptor Proteins, Vesicular Transport/chemistry , Ascorbic Acid/chemistry , Gold/chemistry , HSP90 Heat-Shock Proteins/chemistry , Heterotrimeric GTP-Binding Proteins/chemistry , Metal Nanoparticles/chemistry , Adaptor Proteins, Vesicular Transport/biosynthesis , Adaptor Proteins, Vesicular Transport/genetics , Amino Acid Sequence , Binding Sites , Drug Design , Escherichia coli/genetics , Escherichia coli/metabolism , Fluorescent Dyes , Gene Expression , HSP90 Heat-Shock Proteins/chemical synthesis , Heterotrimeric GTP-Binding Proteins/biosynthesis , Heterotrimeric GTP-Binding Proteins/genetics , Ligands , Metal Nanoparticles/ultrastructure , Molecular Sequence Data , Protein Binding , Protein Structure, Secondary , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Serum Albumin, Bovine/chemistry , Spectrometry, FluorescenceABSTRACT
In this study, a novel Hsp90 inhibitor BJ-B11, was synthesized and evaluated for in vitro antiviral activity against several viruses. Possible anti-HSV-1 mechanisms were also investigated. BJ-B11 displayed no antiviral activity against coxsackievirus B(3) (CVB(3)), human respiratory syncytial virus (RSV) and influenza virus (H1N1), but exhibited potent anti-HSV-1 and HSV-2 activity with EC(50) values of 0.42±0.18 µM and 0.60±0.21 µM, respectively. Additionally, the inhibitory effects of BJ-B11 against HSV-1 were likely to be introduced at early stage of infection. Our results indicate that BJ-B11 with alternative mechanisms of action is potent as an anti-HSV clinical trial candidate.
