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Yang Y, Dong Z, Hu H, Peng J, Sheng Y, Tong Y, Yuan S, Li Z, Yang J, Wells T, Qu Y, Farrell NP, Liu Y. The facile and visualizable identification of broad-spectrum inhibitors of MDM2/p53 using co-expressed protein complexes. Analyst 2019; 144:3773-3781. [PMID: 31089613 DOI: 10.1039/c9an00350a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
MDM2 is a well-known oncoprotein overexpressed in a variety of cancers, and the identification of inhibitors that disrupt the MDM2/p53 interaction is of great interest in anticancer drug development. Here we designed a platform for the facile and visualizable identification of inhibitors of MDM2 using co-expressed protein complexes of MDM2/p53. A hexahistidine-tag on MDM2 allows the binding of the protein complex to the Ni-NTA affinity resin, while the fluorescent protein fused to p53 enables the direct visualization of the interaction of p53 with MDM2. Hence, the inhibition of the MDM2/p53 interaction can be observed with the naked eye. The assay can be set up by directly loading cell lysate to the Ni-NTA affinity resin, and no chemical modification of proteins is needed. In addition to the qualitative analyses, the binding affinity of inhibitors to the MDM2 protein can be quantified by fluorescence titration. The applications of this system have been verified using small molecules and peptide inhibitors. As a proof of concept, we screened a small library using this platform. Interestingly, two types of novel inhibitors of MDM2, including cyclohexyl-triphenylamine derivatives and platinum complexes, were identified and their binding affinities were obtained. Quantitative measurements show that these new types of inhibitors demonstrate a high binding affinity (up to Kd = 51.9 nM) to MDM2.
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Affiliation(s)
- Yang Yang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Zhiqiang Dong
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Hongze Hu
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Junhui Peng
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Yaping Sheng
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Yang Tong
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Siming Yuan
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Zigang Li
- School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, 518055, China
| | - Jiaxiang Yang
- Department of Chemistry, Anhui University, Hefei 230601, China
| | - Thomas Wells
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284-2006, USA
| | - Yun Qu
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284-2006, USA
| | - Nicholas P Farrell
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284-2006, USA
| | - Yangzhong Liu
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
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Investigation of 1-Methylcytosine as a Ligand in Gold(III) Complexes: Synthesis and Protein Interactions. INORGANICS 2018. [DOI: 10.3390/inorganics7010001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The HIV nucleocapsid protein NCp7 was previously shown to play a number of roles in the viral life cycle and was previously identified as a potential target for small molecule intervention. In this work, the synthesis of the previously unreported complexes [Au(dien)(1MeCyt)]3+, [Au(N-Medien)(1MeCyt)]3+, and [Au(dien)(Cyt)]3+ is detailed, and the interactions of these complexes with the models for NCp7 are described. The affinity for these complexes with the target interaction site, the “essential” tryptophan of the C-terminal zinc finger motif of NCp7, was investigated through the use of a fluorescence quenching assay and by 1H-NMR spectroscopy. The association of [Au(dien)(1MeCyt)]3+ as determined through fluorescence quenching is intermediate between the previously reported DMAP and 9-EtGua analogs, while the associations of [Au(N-Medien)(1MeCyt)]3+ and [Au(dien)(Cyt)]3+ are lower than the previously reported complexes. Additionally, NMR investigation shows that the self-association of relevant compounds is negligible. The specifics of the interaction with the C-terminal zinc finger were investigated by circular dichroism spectroscopy and electrospray-ionization mass spectrometry. The interaction is complete nearly immediately upon mixing, and the formation of AuxFn+ (x = 1, 2, or 4; F = apopeptide) concomitant with the loss of all ligands is observed. Additionally, oxidized dimerized peptide was observed for the first time as a product, indicating a reaction via a charge transfer mechanism.
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