1
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Chen Z, Zakrzewska S, Hajare HS, Du Bois J, Minor DL. Expression, purification, and characterization of anuran saxiphilins using thermofluor, fluorescence polarization, and isothermal titration calorimetry. STAR Protoc 2024; 5:102792. [PMID: 38133955 PMCID: PMC10776646 DOI: 10.1016/j.xpro.2023.102792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/10/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Anuran saxiphilins (Sxphs) are "toxin sponge" proteins thought to prevent the lethal effects of small-molecule neurotoxins through sequestration. Here, we present a protocol for the expression, purification, and characterization of Sxphs. We describe steps for using thermofluor, fluorescence polarization, and isothermal titration calorimetry assays that probe Sxph:saxitoxin interactions using a range of sample quantities. These assays are generalizable and can be used for other paralytic shellfish poisoning toxin-binding proteins. For complete details on the use and execution of this protocol, please refer to Chen et al. (2022).1.
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Affiliation(s)
- Zhou Chen
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158-2330, USA
| | - Sandra Zakrzewska
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158-2330, USA
| | - Holly S Hajare
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - J Du Bois
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
| | - Daniel L Minor
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158-2330, USA; Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158-2330, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA 94158-2330, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158-2330, USA; Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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2
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Hua L, Wang D, Wang K, Wang Y, Gu J, Zhang Q, You Q, Wang L. Design of Tracers in Fluorescence Polarization Assay for Extensive Application in Small Molecule Drug Discovery. J Med Chem 2023; 66:10934-10958. [PMID: 37561645 DOI: 10.1021/acs.jmedchem.3c00881] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Development of fluorescence polarization (FP) assays, especially in a competitive manner, is a potent and mature tool for measuring the binding affinities of small molecules. This approach is suitable for high-throughput screening (HTS) for initial ligands and is also applicable for further study of the structure-activity relationships (SARs) of candidate compounds for drug discovery. Buffer and tracer, especially rational design of the tracer, play a vital role in an FP assay system. In this perspective, we provided different kinds of approaches for tracer design based on successful cases in recent years. We classified these tracers by different types of ligands in tracers, including peptide, nucleic acid, natural product, and small molecule. To make this technology accessible for more targets, we briefly described the basic theory and workflow, followed by highlighting the design and application of typical FP tracers from a perspective of medicinal chemistry.
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Affiliation(s)
- Liwen Hua
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Danni Wang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Keran Wang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yuxuan Wang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Jinying Gu
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Qiuyue Zhang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Qidong You
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Lei Wang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
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3
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Scheuplein NJ, Lohr T, Vivoli Vega M, Ankrett D, Seufert F, Kirchner L, Harmer NJ, Holzgrabe U. Fluorescent probe for the identification of potent inhibitors of the macrophage infectivity potentiator (Mip) protein of Burkholderia pseudomallei. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2023; 28:211-222. [PMID: 37001588 DOI: 10.1016/j.slasd.2023.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/02/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023]
Abstract
The macrophage infectivity potentiator (Mip) protein belongs to the immunophilin superfamily. This class of enzymes catalyzes the interconversion between the cis and trans configuration of proline-containing peptide bonds. Mip has been shown to be important for the virulence of a wide range of pathogenic microorganisms, including the Gram-negative bacterium Burkholderia pseudomallei. Small molecules derived from the natural product rapamycin, lacking its immunosuppression-inducing moiety, inhibit Mip's peptidyl-prolyl cis-trans isomerase (PPIase) activity and lead to a reduction in pathogen load in vitro. Here, a fluorescence polarization assay (FPA) to enable the screening and effective development of BpMip inhibitors was established. A fluorescent probe was prepared, derived from previous pipecolic scaffold Mip inhibitors labeled with fluorescein. This probe showed moderate affinity for BpMip and enabled a highly robust FPA suitable for screening large compound libraries with medium- to high-throughput (Z factor ∼ 0.89) to identify potent new inhibitors. The FPA results are consistent with data from the protease-coupled PPIase assay. Analysis of the temperature dependence of the probe's binding highlighted that BpMip's ligand binding is driven by enthalpic rather than entropic effects. This has considerable consequences for the use of low-temperature kinetic assays.
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Affiliation(s)
- Nicolas Julian Scheuplein
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Theresa Lohr
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | | | - Dyan Ankrett
- Living Systems Institute, Stocker Road, Exeter EX4 4QD, UK
| | - Florian Seufert
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Lukas Kirchner
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | | | - Ulrike Holzgrabe
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany.
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4
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Bobone S, Storti C, Calligari P, Stella L. Fluorescence Anisotropy and Polarization in the Characterization of Biomolecular Association Processes and Their Application to Study SH2 Domain Binding Affinity. Methods Mol Biol 2023; 2705:93-112. [PMID: 37668971 DOI: 10.1007/978-1-0716-3393-9_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
Fluorescence anisotropy (or polarization) is a powerful technique to study biomolecular association processes, by following the rotational motions of one of the two partners in the interaction, labeled with a fluorophore. It can be used to determine dissociation constants in solution, down to nM values, and unlabeled ligands can be characterized, too, by using competition experiments. In this chapter, we introduce the basic principles of the technique, compare it with other experimental approaches, and discuss the experimental details with specific examples regarding SH2 domain/phosphopeptide association processes. The experimental protocols to be used in binding experiments and displacement studies are described, as well as the caveats to be considered in performing accurate measurements.
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Affiliation(s)
- Sara Bobone
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome, Italy
| | - Claudia Storti
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome, Italy
| | - Paolo Calligari
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome, Italy
| | - Lorenzo Stella
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome, Italy.
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5
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Gu J, Peng RK, Guo CL, Zhang M, Yang J, Yan X, Zhou Q, Li H, Wang N, Zhu J, Ouyang Q. Construction of a synthetic methodology-based library and its application in identifying a GIT/PIX protein-protein interaction inhibitor. Nat Commun 2022; 13:7176. [PMID: 36418900 PMCID: PMC9684509 DOI: 10.1038/s41467-022-34598-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 10/24/2022] [Indexed: 11/24/2022] Open
Abstract
In recent years, the flourishing of synthetic methodology studies has provided concise access to numerous molecules with new chemical space. These compounds form a large library with unique scaffolds, but their application in hit discovery is not systematically evaluated. In this work, we establish a synthetic methodology-based compound library (SMBL), integrated with compounds obtained from our synthetic researches, as well as their virtual derivatives in significantly larger scale. We screen the library and identify small-molecule inhibitors to interrupt the protein-protein interaction (PPI) of GIT1/β-Pix complex, an unrevealed target involved in gastric cancer metastasis. The inhibitor 14-5-18 with a spiro[bicyclo[2.2.1]heptane-2,3'-indolin]-2'-one scaffold, considerably retards gastric cancer metastasis in vitro and in vivo. Since the PPI targets are considered undruggable as they are hard to target, the successful application illustrates the structural specificity of SMBL, demonstrating its potential to be utilized as compound source for more challenging targets.
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Affiliation(s)
- Jing Gu
- grid.410570.70000 0004 1760 6682Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, 400038 Chongqing, China
| | - Rui-Kun Peng
- grid.410570.70000 0004 1760 6682Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, 400038 Chongqing, China
| | - Chun-Ling Guo
- grid.410570.70000 0004 1760 6682Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, 400038 Chongqing, China
| | - Meng Zhang
- grid.16821.3c0000 0004 0368 8293Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Jie Yang
- grid.410570.70000 0004 1760 6682Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, 400038 Chongqing, China
| | - Xiao Yan
- grid.410570.70000 0004 1760 6682Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, 400038 Chongqing, China
| | - Qian Zhou
- grid.410570.70000 0004 1760 6682Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, 400038 Chongqing, China
| | - Hongwei Li
- grid.410570.70000 0004 1760 6682Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, 400038 Chongqing, China
| | - Na Wang
- grid.410570.70000 0004 1760 6682Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, 400038 Chongqing, China
| | - Jinwei Zhu
- grid.16821.3c0000 0004 0368 8293Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Qin Ouyang
- grid.410570.70000 0004 1760 6682Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, 400038 Chongqing, China
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6
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Definition of a saxitoxin (STX) binding code enables discovery and characterization of the anuran saxiphilin family. Proc Natl Acad Sci U S A 2022; 119:e2210114119. [PMID: 36279441 PMCID: PMC9636910 DOI: 10.1073/pnas.2210114119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
American bullfrog (Rana castesbeiana) saxiphilin (RcSxph) is a high-affinity "toxin sponge" protein thought to prevent intoxication by saxitoxin (STX), a lethal bis-guanidinium neurotoxin that causes paralytic shellfish poisoning (PSP) by blocking voltage-gated sodium channels (NaVs). How specific RcSxph interactions contribute to STX binding has not been defined and whether other organisms have similar proteins is unclear. Here, we use mutagenesis, ligand binding, and structural studies to define the energetic basis of Sxph:STX recognition. The resultant STX "recognition code" enabled engineering of RcSxph to improve its ability to rescue NaVs from STX and facilitated discovery of 10 new frog and toad Sxphs. Definition of the STX binding code and Sxph family expansion among diverse anurans separated by ∼140 My of evolution provides a molecular basis for understanding the roles of toxin sponge proteins in toxin resistance and for developing novel proteins to sense or neutralize STX and related PSP toxins.
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7
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Ding Y, Xing D, Fei Y, Lu B. Emerging degrader technologies engaging lysosomal pathways. Chem Soc Rev 2022; 51:8832-8876. [PMID: 36218065 PMCID: PMC9620493 DOI: 10.1039/d2cs00624c] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Indexed: 08/24/2023]
Abstract
Targeted protein degradation (TPD) provides unprecedented opportunities for drug discovery. While the proteolysis-targeting chimera (PROTAC) technology has already entered clinical trials and changed the landscape of small-molecule drugs, new degrader technologies harnessing alternative degradation machineries, especially lysosomal pathways, have emerged and broadened the spectrum of degradable targets. We have recently proposed the concept of autophagy-tethering compounds (ATTECs) that hijack the autophagy protein microtubule-associated protein 1A/1B light chain 3 (LC3) for targeted degradation. Other groups also reported degrader technologies engaging lysosomal pathways through different mechanisms including AUTACs, AUTOTACs, LYTACs and MoDE-As. In this review, we analyse and discuss ATTECs along with other lysosomal-relevant degrader technologies. Finally, we will briefly summarize the current status of these degrader technologies and envision possible future studies.
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Affiliation(s)
- Yu Ding
- Neurology Department at Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Life Sciences, Fudan University, Shanghai, China.
| | - Dong Xing
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China.
| | - Yiyan Fei
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai, China.
| | - Boxun Lu
- Neurology Department at Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Life Sciences, Fudan University, Shanghai, China.
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8
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Zhong J, Guo Y, Lu S, Song K, Wang Y, Feng L, Zheng Z, Zhang Q, Wei J, Sang P, Shi Y, Cai J, Chen G, Liu CY, Yang X, Zhang J. Rational design of a sensitivity-enhanced tracer for discovering efficient APC-Asef inhibitors. Nat Commun 2022; 13:4961. [PMID: 36002443 PMCID: PMC9402538 DOI: 10.1038/s41467-022-32612-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 08/08/2022] [Indexed: 11/24/2022] Open
Abstract
The adenomatous polyposis coli (APC)–Rho guanine nucleotide exchange factor 4 (Asef) protein–protein interaction (PPI) is essential for colorectal cancer metastasis, making it a promising drug target. Herein, we obtain a sensitivity-enhanced tracer (tracer 7) with a high binding affinity (Kd = 0.078 μM) and wide signal dynamic range (span = 251 mp). By using tracer 7 in fluorescence-polarization assays for APC–Asef inhibitor screening, we discover a best-in-class inhibitor, MAI-516, with an IC50 of 0.041 ± 0.004 μM and a conjugated transcriptional transactivating sequence for generating cell-permeable MAIT-516. MAIT-516 inhibits CRC cell migration by specifically hindering the APC–Asef PPI. Furthermore, MAIT-516 exhibits no cytotoxic effects on normal intestinal epithelial cell and colorectal cancer cell growth. Overall, we develop a sensitivity-enhanced tracer for fluorescence polarization assays, which is used for the precise quantification of high-activity APC–Asef inhibitors, thereby providing insight into PPI drug development. The adenomatous polyposis coli (APC)–Asef protein interaction is essential for colorectal cancer metastasis. Here, the authors present the rational design of a sensitivity-enhanced tracer for fluorescence polarization assays, enabling them to discover more efficient APC–Asef interaction inhibitors.
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Affiliation(s)
- Jie Zhong
- State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuegui Guo
- Department of Colorectal and Anal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shaoyong Lu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kun Song
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Wang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li Feng
- Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhen Zheng
- Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiufen Zhang
- Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jiacheng Wei
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Peng Sang
- Department of Chemistry, University of South Florida, Tampa, FL, USA
| | - Yan Shi
- Department of Chemistry, University of South Florida, Tampa, FL, USA
| | - Jianfeng Cai
- Department of Chemistry, University of South Florida, Tampa, FL, USA
| | - Guoqiang Chen
- Research Unit of Stress and Cancer, Chinese Academy of Medical Sciences, Shanghai, China
| | - Chen-Ying Liu
- Department of Colorectal and Anal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Xiuyan Yang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
| | - Jian Zhang
- State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China.
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9
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Intrinsically Fluorescent Anti-Cancer Drugs. BIOLOGY 2022; 11:biology11081135. [PMID: 36009762 PMCID: PMC9405238 DOI: 10.3390/biology11081135] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022]
Abstract
At present, about one-third of the total protein targets in the pharmaceutical research sector are kinase-based. While kinases have been attractive targets to combat many diseases, including cancer, selective kinase inhibition has been challenging, because of the high degree of structural homology in the active site where many kinase inhibitors bind. Despite efficacy as cancer drugs, kinase inhibitors can exhibit limited target specificity and rationalizing their target profiles in the context of precise molecular mechanisms or rearrangements is a major challenge for the field. Spectroscopic approaches such as infrared, Raman, NMR and fluorescence have the potential to provide significant insights into drug-target and drug-non-target interactions because of sensitivity to molecular environment. This review places a spotlight on the significance of fluorescence for extracting information related to structural properties, discovery of hidden conformers in solution and in target-bound state, binding properties (e.g., location of binding sites, hydrogen-bonding, hydrophobicity), kinetics as well as dynamics of kinase inhibitors. It is concluded that the information gleaned from an understanding of the intrinsic fluorescence from these classes of drugs may aid in the development of future drugs with improved side-effects and less disease resistance.
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10
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A Practical and
High‐Affinity
Fluorescent Probe for Butyrylcholinesterase: A Good Strategy for Binding Affinity Characterization. CHINESE J CHEM 2022. [DOI: 10.1002/cjoc.202100910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Jang B, Jang H, Kim H, Kim M, Jeong M, Lee GS, Lee K, Lee H. Protein-RNA interaction guided chemical modification of Dicer substrate RNA nanostructures for superior in vivo gene silencing. J Control Release 2021; 343:57-65. [PMID: 34763005 DOI: 10.1016/j.jconrel.2021.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 01/11/2023]
Abstract
Dicer substrate RNA is an alternative gene silencing agent to canonical siRNA. Enhanced in vitro gene silencing can be achieved with RNA substrates by facilitating Ago loading of dsRNA after Dicer processing. However, the in vivo use of Dicer substrate RNA has been hindered by its instability and immunogenicity in the body due to the lack of proper chemical modification in the structure. Here, we report a universal chemical modification approach for Dicer substrate RNA nanostructures by optimizing protein-RNA interactions in the RNAi pathway. Proteins involved in the RNAi pathway were utilized for evaluating their recognition and binding of substrate RNA. It was found that conventional chemical modifications could severely affect the binding and processing of substrate RNA, consequently reducing RNAi activity. Protein-RNA interaction guided chemical modification was introduced to RNA nanostructures, and their gene silencing activity was assessed. The optimized RNA nanostructures showed excellent binding and processability with RNA binding proteins and offered the enhancement of in vivo EC50 up to 1/8 of its native form.
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Affiliation(s)
- Bora Jang
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Hyejin Jang
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Hyunsook Kim
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Minjeong Kim
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Michaela Jeong
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Gyeong Seok Lee
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Kyuri Lee
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Republic of Korea; College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju 52828, Republic of Korea.
| | - Hyukjin Lee
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Republic of Korea.
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12
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POLArIS, a versatile probe for molecular orientation, revealed actin filaments associated with microtubule asters in early embryos. Proc Natl Acad Sci U S A 2021; 118:2019071118. [PMID: 33674463 DOI: 10.1073/pnas.2019071118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Biomolecular assemblies govern the physiology of cells. Their function often depends on the changes in molecular arrangements of constituents, both in the positions and orientations. While recent advancements of fluorescence microscopy including super-resolution microscopy have enabled us to determine the positions of fluorophores with unprecedented accuracy, monitoring the orientation of fluorescently labeled molecules within living cells in real time is challenging. Fluorescence polarization microscopy (FPM) reports the orientation of emission dipoles and is therefore a promising solution. For imaging with FPM, target proteins need labeling with fluorescent probes in a sterically constrained manner, but because of difficulties in the rational three-dimensional design of protein connection, a universal method for constrained tagging with fluorophore was not available. Here, we report POLArIS, a genetically encoded and versatile probe for molecular orientation imaging. Instead of using a direct tagging approach, we used a recombinant binder connected to a fluorescent protein in a sterically constrained manner that can target specific biomolecules of interest by combining with phage display screening. As an initial test case, we developed POLArISact, which specifically binds to F-actin in living cells. We confirmed that the orientation of F-actin can be monitored by observing cells expressing POLArISact with FPM. In living starfish early embryos expressing POLArISact, we found actin filaments radially extending from centrosomes in association with microtubule asters during mitosis. By taking advantage of the genetically encoded nature, POLArIS can be used in a variety of living specimens, including whole bodies of developing embryos and animals, and also be expressed in a cell type/tissue specific manner.
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13
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McPherson KS, Korzhnev DM. Targeting protein-protein interactions in the DNA damage response pathways for cancer chemotherapy. RSC Chem Biol 2021; 2:1167-1195. [PMID: 34458830 PMCID: PMC8342002 DOI: 10.1039/d1cb00101a] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 06/20/2021] [Indexed: 12/11/2022] Open
Abstract
Cellular DNA damage response (DDR) is an extensive signaling network that orchestrates DNA damage recognition, repair and avoidance, cell cycle progression and cell death. DDR alteration is a hallmark of cancer, with the deficiency in one DDR capability often compensated by a dependency on alternative pathways endowing cancer cells with survival and growth advantage. Targeting these DDR pathways has provided multiple opportunities for the development of cancer therapies. Traditional drug discovery has mainly focused on catalytic inhibitors that block enzyme active sites, which limits the number of potential drug targets within the DDR pathways. This review article describes the emerging approach to the development of cancer therapeutics targeting essential protein-protein interactions (PPIs) in the DDR network. The overall strategy for the structure-based design of small molecule PPI inhibitors is discussed, followed by an overview of the major DNA damage sensing, DNA repair, and DNA damage tolerance pathways with a specific focus on PPI targets for anti-cancer drug design. The existing small molecule inhibitors of DDR PPIs are summarized that selectively kill cancer cells and/or sensitize cancers to front-line genotoxic therapies, and a range of new PPI targets are proposed that may lead to the development of novel chemotherapeutics.
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Affiliation(s)
- Kerry Silva McPherson
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center Farmington CT 06030 USA +1 860 679 3408 +1 860 679 2849
| | - Dmitry M Korzhnev
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center Farmington CT 06030 USA +1 860 679 3408 +1 860 679 2849
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14
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Ligand Discovery: High-Throughput Binding: Fluorescence Polarization (Anisotropy). Methods Mol Biol 2021. [PMID: 33877601 DOI: 10.1007/978-1-0716-1197-5_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
High-throughput assays based on fluorescence polarization (or fluorescence anisotropy) technology have often been employed for primary hit-finding in drug discovery. These binding assays provide a homogeneous format and consistent performance and offer advantages over some other optical methods. Developments in assay design and improvements in fluorescent probes have enabled the application of the technique to even complex biological systems. Here we describe the practical considerations for development of FP assays applied in high-throughput screening, including fluorophore selection, assay design, data analysis, and approaches for detecting compound interference.
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15
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Takioku M, Takamura Y, Fujihara M, Watanabe M, Yamada S, Kawasaki M, Ito S, Nakano S, Kakuta H. Creation of Fluorescent RXR Antagonists Based on CBTF-EE and Application to a Fluorescence Polarization Binding Assay. ACS Med Chem Lett 2021; 12:1024-1029. [PMID: 34141088 DOI: 10.1021/acsmedchemlett.1c00201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/05/2021] [Indexed: 01/08/2023] Open
Abstract
Retinoid X receptor (RXR) ligands often bind in modes in which the carboxy group forms a hydrogen bond inside the ligand-binding pocket (LBP). However, our previously reported RXR antagonist, CBTF-EE (4a), binds with its carboxy group directed outside the LBP and its alkoxy side chain located inside the LBP. Here, we examined the binding modes of 4b and 4c bearing a nitrobenzoxadiazole (NBD) or boron-dipyrromethene (BODIPY) fluorophore, respectively, at the end of the alkoxy chain of 4a. Both compounds function as RXR antagonists. 4c, but not 4b, was available for a fluorescence polarization binding assay, indicating that rotation of BODIPY, but not NBD, is restricted in the bound state. The fluorescence findings, supported by docking simulations, suggest the fluorophores are located outside the LBP, so that the binding mode of 4b and 4c is different from that of 4a. The assay results were highly correlated with those of a [3H]9-cis-retinoic acid assay.
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Affiliation(s)
- Maho Takioku
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan
| | - Yuta Takamura
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan
| | - Michiko Fujihara
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan
- AIBIOS Co. Ltd., Tri-Seven Roppongi 8F 7-7-7 Roppongi, Minato-ku, Tokyo 106-0032, Japan
| | - Masaki Watanabe
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan
| | - Shoya Yamada
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan
- Research Fellowship Division, Japan Society for the Promotion of Science, Sumitomo-Ichibancho FS Bldg., 8 Ichibancho, Chiyoda-ku, Tokyo 102-8472, Japan
| | - Mayu Kawasaki
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52- 1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Sohei Ito
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52- 1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Shogo Nakano
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52- 1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Hiroki Kakuta
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan
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16
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Identification of Small-Molecule Activators of the Ubiquitin Ligase E6AP/UBE3A and Angelman Syndrome-Derived E6AP/UBE3A Variants. Cell Chem Biol 2020; 27:1510-1520.e6. [PMID: 32966807 DOI: 10.1016/j.chembiol.2020.08.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 08/04/2020] [Accepted: 08/24/2020] [Indexed: 01/03/2023]
Abstract
Genetic aberrations of the UBE3A gene encoding the E3 ubiquitin ligase E6AP underlie the development of Angelman syndrome (AS). Approximately 10% of AS individuals harbor UBE3A genes with point mutations, frequently resulting in the expression of full-length E6AP variants with defective E3 activity. Since E6AP exists in two states, an inactive and an active one, we hypothesized that distinct small molecules can stabilize the active state and that such molecules may rescue the E3 activity of AS-derived E6AP variants. Therefore, we established an assay that allows identifying modulators of E6AP in a high-throughput format. We identified several compounds that not only stimulate wild-type E6AP but also rescue the E3 activity of certain E6AP variants. Moreover, by chemical cross-linking coupled to mass spectrometry we provide evidence that the compounds stabilize an active conformation of E6AP. Thus, these compounds represent potential lead structures for the design of drugs for AS treatment.
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17
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Cho J, Park J, Kim EE, Song EJ. Assay Systems for Profiling Deubiquitinating Activity. Int J Mol Sci 2020; 21:E5638. [PMID: 32781716 PMCID: PMC7460613 DOI: 10.3390/ijms21165638] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/04/2020] [Accepted: 08/04/2020] [Indexed: 01/22/2023] Open
Abstract
Deubiquitinating enzymes regulate various cellular processes, particularly protein degradation, localization, and protein-protein interactions. The dysregulation of deubiquitinating enzyme (DUB) activity has been linked to several diseases; however, the function of many DUBs has not been identified. Therefore, the development of methods to assess DUB activity is important to identify novel DUBs, characterize DUB selectivity, and profile dynamic DUB substrates. Here, we review various methods of evaluating DUB activity using cell lysates or purified DUBs, as well as the types of probes used in these methods. In addition, we introduce some techniques that can deliver DUB probes into the cells and cell-permeable activity-based probes to directly visualize and quantify DUB activity in live cells. This review could contribute to the development of DUB inhibitors by providing important information on the characteristics and applications of various probes used to evaluate and detect DUB activity in vitro and in vivo.
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Affiliation(s)
- Jinhong Cho
- Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 02792, Korea; (J.C.); (E.E.K.)
| | - Jinyoung Park
- Molecular Recognition Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea;
| | - Eunice EunKyeong Kim
- Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 02792, Korea; (J.C.); (E.E.K.)
| | - Eun Joo Song
- Graduate School of Pharmaceutical Sciences and College of Pharmacy, Ewha Womans University, Seoul 03760, Korea
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18
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Wilder PT, Varney KM, Weber DJ. Targeting S100 Calcium-Binding Proteins with Small Molecule Inhibitors. Methods Mol Biol 2019; 1929:291-310. [PMID: 30710281 DOI: 10.1007/978-1-4939-9030-6_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
S100B is a small, dimeric, calcium-binding protein that is implicated in various diseases, most significantly cancer; therefore, there is interest in identifying S100B inhibitors that may have therapeutic value (Bresnick et al. Nat Rev Cancer 15:96-109, 2015; Chong et al. Curr Med Chem 23:1571-1596). Two fluorescence polarization competition assays (FPCA) are described here for S100B and S100A1 that are amenable to high-throughput screening (HTS) campaigns and can be used to determine the binding affinity (K i) of the inhibitors. One FPCA is used to identify and characterize inhibitors of S100B with the aim of finding new therapeutics, and the other was developed as a counter-screen to avoid inhibitors of S100A1 due to its role in regulating skeletal and cardiac muscle function. Also outlined are methods for expressing and purifying S100B and S100A1 in quantities needed for performing large HTS campaigns.
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Affiliation(s)
- Paul T Wilder
- Center for Biomolecular Therapeutics (CBT), Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA.,University of Maryland Marlene and Stewart Greenebaum Comprehesive Cancer Center, Baltimore, MD, USA
| | - Kristen M Varney
- Center for Biomolecular Therapeutics (CBT), Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA.,University of Maryland Marlene and Stewart Greenebaum Comprehesive Cancer Center, Baltimore, MD, USA
| | - David J Weber
- Center for Biomolecular Therapeutics (CBT), Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA. .,University of Maryland Marlene and Stewart Greenebaum Comprehesive Cancer Center, Baltimore, MD, USA.
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19
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Turchi JJ, VanderVere-Carozza PS. Small-Molecule Inhibitor Screen for DNA Repair Proteins. Methods Mol Biol 2019; 1999:217-221. [PMID: 31127579 DOI: 10.1007/978-1-4939-9500-4_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
With the recent interest in targeting the DNA damage response (DDR) and DNA repair, new screening methodologies are needed to broaden the scope of targetable proteins beyond kinases and traditional enzymes. Many of the proteins involved in the DDR and repair impart their activity by making specific contacts with DNA. These protein-nucleic acid interactions represent a tractable target for perturbation with small molecules. We describe a high throughput, solution-based equilibrium binding fluorescence polarization assay that can be applied to a wide array of protein-nucleic acid interactions. The assay is sensitive, stable, and able to identify small molecules capable of blocking DNA-protein interactions.
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Affiliation(s)
- John J Turchi
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA. .,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
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20
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Tabuchi Y, Taki M. Fluorescent "keep-on" type pharmacophore obtained from dynamic combinatorial library of Schiff bases. Anal Bioanal Chem 2018; 410:6713-6717. [PMID: 30099565 DOI: 10.1007/s00216-018-1303-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 07/31/2018] [Indexed: 12/30/2022]
Abstract
We established a novel principle for fluorescence detection of a target protein. A low-molecular-weight fluorescent pharmacophore, as a targeted probe, was selected from a dynamic combinatorial library of Schiff bases. The pharmacophore retains its fluorescence when bound to the hydrophobic site of the target, whereas it loses it because of hydrolysis when unbound. Graphical abstract We describe a novel concept for detection of a target protein (i.e., HSA) by using a keep-on-type fluorescent pharmacophore which is discovered from a dynamic combinatorial library of Schiff bases. When the target is absent, the keep-on-pharmacophore is degraded by hydrolysis, with the result that we can see no fluorescence.
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Affiliation(s)
- Yudai Tabuchi
- Department of Engineering Science, Bioscience and Technology Program, The Graduate School of Informatics and Engineering, The University of Electro-Communications (UEC), 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan
| | - Masumi Taki
- Department of Engineering Science, Bioscience and Technology Program, The Graduate School of Informatics and Engineering, The University of Electro-Communications (UEC), 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan.
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21
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Gul S. Epigenetic assays for chemical biology and drug discovery. Clin Epigenetics 2017; 9:41. [PMID: 28439316 PMCID: PMC5399855 DOI: 10.1186/s13148-017-0342-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 04/12/2017] [Indexed: 12/27/2022] Open
Abstract
The implication of epigenetic abnormalities in many diseases and the approval of a number of compounds that modulate specific epigenetic targets in a therapeutically relevant manner in cancer specifically confirms that some of these targets are druggable by small molecules. Furthermore, a number of compounds are currently in clinical trials for other diseases including cardiovascular, neurological and metabolic disorders. Despite these advances, the approved treatments for cancer only extend progression-free survival for a relatively short time and being associated with significant side effects. The current clinical trials involving the next generation of epigenetic drugs may address the disadvantages of the currently approved epigenetic drugs. The identification of chemical starting points of many drugs often makes use of screening in vitro assays against libraries of synthetic or natural products. These assays can be biochemical (using purified protein) or cell-based (using for example, genetically modified, cancer cell lines or primary cells) and performed in microtiter plates, thus enabling a large number of samples to be tested. A considerable number of such assays are available to monitor epigenetic target activity, and this review provides an overview of drug discovery and chemical biology and describes assays that monitor activities of histone deacetylase, lysine-specific demethylase, histone methyltransferase, histone acetyltransferase and bromodomain. It is of critical importance that an appropriate assay is developed and comprehensively validated for a given drug target prior to screening in order to improve the probability of the compound progressing in the drug discovery value chain.
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Affiliation(s)
- Sheraz Gul
- Fraunhofer Institute for Molecular Biology and Applied Ecology - ScreeningPort, Schnackenburgallee 114, 22525 Hamburg, Germany
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