1
|
Chen X, Leyendecker S. Kinematic analysis of kinases and their oncogenic mutations - Kinases and their mutation kinematic analysis. Mol Inform 2024; 43:e202300250. [PMID: 38850084 DOI: 10.1002/minf.202300250] [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: 09/19/2023] [Revised: 01/25/2024] [Accepted: 03/14/2024] [Indexed: 06/09/2024]
Abstract
Protein kinases are crucial cellular enzymes that facilitate the transfer of phosphates from adenosine triphosphate (ATP) to their substrates, thereby regulating numerous cellular activities. Dysfunctional kinase activity often leads to oncogenic conditions. Chosen by using structural similarity to 5UG9, we selected 79 crystal structures from the PDB and based on the position of the phenylalanine side chain in the DFG motif, we classified these 79 crystal structures into 5 group clusters. Our approach applies our kinematic flexibility analysis (KFA) to explore the flexibility of kinases in various activity states and examine the impact of the activation loop on kinase structure. KFA enables the rapid decomposition of macromolecules into different flexibility regions, allowing comprehensive analysis of conformational structures. The results reveal that the activation loop of kinases acts as a "lock" that stabilizes the active conformation of kinases by rigidifying the adjacent α-helices. Furthermore, we investigate specific kinase mutations, such as the L858R mutation commonly associated with non-small cell lung cancer, which induces increased flexibility in active-state kinases. In addition, through analyzing the hydrogen bond pattern, we examine the substructure of kinases in different states. Notably, active-state kinases exhibit a higher occurrence of α-helices compared to inactive-state kinases. This study contributes to the understanding of biomolecular conformation at a level relevant to drug development.
Collapse
Affiliation(s)
- Xiyu Chen
- Institute of Applied Dynamics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Sigrid Leyendecker
- Institute of Applied Dynamics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany
| |
Collapse
|
2
|
Screening assays for tyrosine kinase inhibitors:A review. J Pharm Biomed Anal 2022; 223:115166. [DOI: 10.1016/j.jpba.2022.115166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/13/2022] [Accepted: 11/14/2022] [Indexed: 11/16/2022]
|
3
|
Wang J, Yang X, Xi L, Wu XN. Kinase Activity Assay Using Unspecific Substrate or Specific Synthetic Peptides. Methods Mol Biol 2021; 2358:229-237. [PMID: 34270059 DOI: 10.1007/978-1-0716-1625-3_17] [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: 06/13/2023]
Abstract
Phosphorylation of a substrate by protein kinases leads to the activation or inactivation of numerous signaling pathways and metabolic processes. The assessment of kinase activity by using a specific or generic substrate plays a crucial role in characterization of kinase specificity and activity. Here we describe a protocol using either a synthetic peptide as a specific substrate or using myelin basic protein (MBP) as a generic substrate for the kinase activity assay. The kinase of interest is fused with a GFP (green fluorescent protein) tag and can be purified by GFP magnetic beads. Kinase-GFP complexes are then incubated with ATP, substrate, and coordinated reaction reagent for the kinase reaction. The assay is then quantified through mass spectrometry or enzymatic luminescence.
Collapse
Affiliation(s)
- Jiahui Wang
- Department of Plant Systems Biology, University of Hohenheim, Stuttgart, Germany
| | - Xiaolin Yang
- State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, China
| | - Lin Xi
- Department of Plant Systems Biology, University of Hohenheim, Stuttgart, Germany
| | - Xu Na Wu
- State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, China.
| |
Collapse
|
4
|
Kruk M, Widstrom N, Jena S, Wolter NL, Blankenhorn JF, Abdalla I, Yang TY, Parker LL. Assays for tyrosine phosphorylation in human cells. Methods Enzymol 2019; 626:375-406. [PMID: 31606083 DOI: 10.1016/bs.mie.2019.06.026] [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: 12/13/2022]
Abstract
Tyrosine kinases are important for many cellular processes and disruption of their regulation is a factor in diseases like cancer, therefore they are a major target of anticancer drugs. There are many ways to measure tyrosine kinase activity in cells by monitoring endogenous substrate phosphorylation, or by using peptide substrates and incubating them with cell lysates containing active kinases. However, most of these strategies rely on antibodies and/or are limited in how accurately they model the intracellular environment. In cases in which activity needs to be measured in cells, but endogenous substrates are not known and/or suitable phosphospecific antibodies are not available, cell-deliverable peptide substrates can be an alternative and can provide information on activation and inhibition of kinases in intact, live cells. In this chapter, we review this methodology and provide a protocol for measuring Abl kinase activity in human cells using enzyme-linked immunosorbent assay (ELISA) with a generic antiphosphotyrosine antibody for detection.
Collapse
Affiliation(s)
- Monica Kruk
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Naomi Widstrom
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Sampreeti Jena
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Nicole L Wolter
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - John F Blankenhorn
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Ibrahim Abdalla
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Tzu-Yi Yang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Laurie L Parker
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States.
| |
Collapse
|
5
|
Turner AH, Lebhar MS, Proctor A, Wang Q, Lawrence DS, Allbritton NL. Rational Design of a Dephosphorylation-Resistant Reporter Enables Single-Cell Measurement of Tyrosine Kinase Activity. ACS Chem Biol 2016; 11:355-62. [PMID: 26587880 DOI: 10.1021/acschembio.5b00667] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although peptide-based reporters of protein tyrosine kinase (PTK) activity have been used to study PTK enzymology in vitro, the application of these reporters to intracellular conditions is compromised by their dephosphorylation, preventing PTK activity measurements. Nonproteinogenic amino acids may be utilized to rationally design selective peptidic ligands by accessing greater chemical and structural diversity than is available using the native amino acids. We describe a peptidic reporter that, upon phosphorylation by the epidermal growth factor receptor (EGFR), is resistant to dephosphorylation both in vitro and in cellulo. The reporter contains a conformationally constrained phosphorylatable moiety (7-(S)-hydroxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) in the place of L-tyrosine and is efficiently phosphorylated in A431 epidermoid carcinoma cells. Dephosphorylation of the reporter occurs 3 orders of magnitude more slowly compared with that of the conventional tyrosine-containing reporter.
Collapse
Affiliation(s)
| | - Michael S. Lebhar
- Joint
Department of Biomedical Engineering, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 and North Carolina State University,
Raleigh, North Carolina 27695, United States
| | | | | | | | - Nancy L. Allbritton
- Joint
Department of Biomedical Engineering, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 and North Carolina State University,
Raleigh, North Carolina 27695, United States
| |
Collapse
|
6
|
Faggi E, Pérez Y, Luis SV, Alfonso I. Supramolecular protection from the enzymatic tyrosine phosphorylation in a polypeptide. Chem Commun (Camb) 2016; 52:8142-5. [DOI: 10.1039/c6cc03875a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Two pseudopeptidic cages bind the EYE peptide motif of poly(EY) in buffered water, as shown by NMR and fluorescence spectroscopy. This supramolecular interaction protects the Tyr residues from the enzymatic phosphorylation by PTK.
Collapse
Affiliation(s)
- Enrico Faggi
- Department of Biological Chemistry and Molecular Modelling
- IQAC-CSIC
- Barcelona
- Spain
| | | | - Santiago V. Luis
- Department of Inorganic and Organic Chemistry
- ESTCE Universitat Jaume I
- Castellón
- Spain
| | - Ignacio Alfonso
- Department of Biological Chemistry and Molecular Modelling
- IQAC-CSIC
- Barcelona
- Spain
| |
Collapse
|
7
|
Abstract
Due to their important roles in cellular signaling and their dysfunctions being linked to diseases, kinases have become a class of proteins being actively pursued as potential drug targets. Biochemical assays for kinases have been developed in various formats to facilitate inhibitor screening and selectivity profiling. Here, we focus on one such technology: homogeneous time-resolved fluorescence (HTRF). In this chapter, we describe the methods of developing an HTRF kinase assay using mutant EGFR enzyme as an example. We show how to determine the kinetic parameter of the enzyme (ATP K m), as well as how to study the inhibitor mechanism of action (MoA) exemplified by inhibitors of different MoAs. All methods described here can be readily applied to other kinases with minor modifications.
Collapse
Affiliation(s)
- Yong Jia
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, CA, 92121, USA.
| | - Mari Manuia
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, CA, 92121, USA
| | - Jose Juarez
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, CA, 92121, USA
| |
Collapse
|
8
|
Fabbro D, Cowan-Jacob SW, Moebitz H. Ten things you should know about protein kinases: IUPHAR Review 14. Br J Pharmacol 2015; 172:2675-700. [PMID: 25630872 DOI: 10.1111/bph.13096] [Citation(s) in RCA: 233] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Revised: 12/31/2014] [Accepted: 01/20/2015] [Indexed: 12/12/2022] Open
Abstract
Many human malignancies are associated with aberrant regulation of protein or lipid kinases due to mutations, chromosomal rearrangements and/or gene amplification. Protein and lipid kinases represent an important target class for treating human disorders. This review focus on 'the 10 things you should know about protein kinases and their inhibitors', including a short introduction on the history of protein kinases and their inhibitors and ending with a perspective on kinase drug discovery. Although the '10 things' have been, to a certain extent, chosen arbitrarily, they cover in a comprehensive way the past and present efforts in kinase drug discovery and summarize the status quo of the current kinase inhibitors as well as knowledge about kinase structure and binding modes. Besides describing the potentials of protein kinase inhibitors as drugs, this review also focus on their limitations, particularly on how to circumvent emerging resistance against kinase inhibitors in oncological indications.
Collapse
Affiliation(s)
| | | | - Henrik Moebitz
- Novartis Institutes of Biomedical Research, Basel, Switzerland
| |
Collapse
|
9
|
Azad T, Tashakor A, Hosseinkhani S. Split-luciferase complementary assay: applications, recent developments, and future perspectives. Anal Bioanal Chem 2014; 406:5541-60. [DOI: 10.1007/s00216-014-7980-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/22/2014] [Accepted: 06/16/2014] [Indexed: 12/19/2022]
|
10
|
Abstract
BACKGROUND Homogeneous time-resolved fluorescence (HTRF) is a fluorescence resonance energy transfer-based technology used to measure bimolecular interactions. It has been applied successfully to kinase assays and has become an important tool in kinase drug discovery. OBJECTIVE This article reviews the current status of HTRF technology in biochemical and cellular kinase assays. METHODS Recent literature and meeting reports on HTRF kinase assays are reviewed, and their principles, advantages and drawbacks, current status and the potential applications in kinase drug discovery are discussed. RESULTS/CONCLUSION HTRF kinase assays are homogeneous, robust, sensitive, easy to miniaturize and high-throughput. This assay format is versatile, as both peptide and protein substrates can be used, and high ATP concentrations are tolerated, which enables the assay to be performed under conditions mimicking the physiological environment. HTRF kinase assays have been applied to both high-throughput screening and compound mechanistic studies. Besides protein kinases, the technology has now been expanded into the lipid kinase family. Furthermore, the utility of HTRF technology in cellular assays is emerging. HTRF kinase assays are a great addition to the toolbox for kinase drug discovery.
Collapse
Affiliation(s)
- Yong Jia
- Group Leader Genomics Institute of the Novartis Research Foundation, Department of Kinase Biology, 10675 John J Hopkins Dr, San Diego, CA 92121, USA +858 812 1728 ; +858 812 1918 ;
| |
Collapse
|
11
|
Ames RS, Lu Q. Viral-mediated gene delivery for cell-based assays in drug discovery. Expert Opin Drug Discov 2013; 4:243-56. [PMID: 23489124 DOI: 10.1517/17460440902751599] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Adenovirus, retrovirus and lentivirus-based vectors, originally engineered and optimized for in vivo and ex vivo gene therapy, have become increasingly useful for viral-mediated gene delivery to support in vitro cell-based assays. Viral vectors underpin functional genomics screening of cDNA, shRNA and aptamer libraries, are used for a variety of target validation studies and importantly, for high-throughput cell-based drug discovery and compound profiling assays. The baculovirus/insect cell expression system had gained prevalence as a tool for recombinant protein production when it was observed that recombinant baculovirus vectors too could serve as efficient gene delivery vehicles for a wide range of mammalian cells. Although the use of baculovirus vectors in vivo has lagged behind retroviral, adenoviral and lentiviral vectors, they have gained prominence for development of in vitro cell-based assays due to the ease of generation, broad host range and excellent biosafety profile. There is an increasing emphasis on cell-based assays in high-throughput automated drug discovery laboratories and a variety of commercially available viral-vectors can be used for supporting these assays. OBJECTIVE We compare and contrast the current viral-mediated gene delivery vector systems and highlight their suitability for cell-based drug discovery assays. CONCLUSION Viral-mediated gene delivery is increasingly being used in support of genome scale target validation studies and cell-based assay development for specific drug target genes such as ion channels, G protein-coupled receptors and intracellular enzymes. The choice of a delivery system over another for a particular application is largely dictated by the cell types and cell lines in use, virus cellular tropism, assay throughput, safety requirements and ease/cost of reagent generation.
Collapse
Affiliation(s)
- Robert S Ames
- Molecular Discovery Research, GlaxoSmithKline R&D, UE0433, 709 Swedeland Road, King of Prussia, PA 19406, USA +1 610 270 7602 ; +1 610 270 7359 ;
| | | |
Collapse
|
12
|
Zhou G, Yan X, Wu D, Kron SJ. Photocleavable peptide-conjugated magnetic beads for protein kinase assays by MALDI-TOF MS. Bioconjug Chem 2011; 21:1917-24. [PMID: 20860375 DOI: 10.1021/bc1003058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Peptides were immobilized onto superparamagnetic beads via photocleavable linkers. This enabled simple, rapid, and label-free protein kinase assays via MALDI-TOF MS detection of substrate peptide phosphorylation. Abltide, a model substrate for the Abl protein tyrosine kinase model, was coupled onto amine-terminated beads, incubated with ATP and recombinant c-Abl kinase, and released and further detected to determine phosphorylation. Abltide phosphorylation was found to depend significantly on the length and composition of linkers to the bead surface. Inserting a diblock spacer of poly(glycine) and poly(ethylene glycol) segments markedly enhanced phosphorylation. To validate the assay, the activity of two small-molecule kinase inhibitors, imatinib and dasatinib, which target the oncogenic mutant tyrosine kinase Bcr-Abl to treat chronic myeloid leukemia (CML), was tested. Examining inhibition of the purified c-Abl or Bcr-Abl in K562 CML cell extracts, IC(50) values were determined to be consistent with the literature. This simple, label-free, MALDI-based protein kinase assay can be readily adapted to allow multiplexed assays of multiple peptide substrates and/or analysis of alternative post-translational modifications as a tool for drug discovery and clinical testing.
Collapse
Affiliation(s)
- Guangchang Zhou
- Ludwig Center for Metastasis Research, The University of Chicago, Chicago, Illinois 60637, USA
| | | | | | | |
Collapse
|
13
|
Ghadiali JE, Cohen BE, Stevens MM. Protein kinase-actuated resonance energy transfer in quantum dot--peptide conjugates. ACS NANO 2010; 4:4915-4919. [PMID: 20731464 DOI: 10.1021/nn101293s] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Bioconjugates of quantum dot nanocrystals possess unique optical properties that allow them to serve as exceptional biological imaging and sensing reagents. Protein kinases are an important family of enzymes that phosphorylate serine, threonine, or tyrosine side chains and are critical in cell signaling and cancer biology, but despite their biomedical and pharmaceutical significance, their activity has been little explored using quantum dot technology. We demonstrate that self-assembled peptide-quantum dot conjugates can serve as surrogate substrates in a simple homogeneous assay for protein kinase activity. Enzymatic phosphorylation of the peptide-conjugates is detected by means of a complementary FRET-acceptor labeled antiphosphotyrosine antibody, with formation of the immunocomplex resulting in energy transfer between the quantum dot and FRET acceptor molecules. This approach should facilitate the development of new assays for protein kinases and other enzymes based on quantum dot FRET donors.
Collapse
Affiliation(s)
- James E Ghadiali
- Department of Materials, Imperial College London, Exhibition Road, London, UK
| | | | | |
Collapse
|
14
|
Li H, Totoritis RD, Lor LA, Schwartz B, Caprioli P, Jurewicz AJ, Zhang G. Evaluation of an antibody-free ADP detection assay: ADP-Glo. Assay Drug Dev Technol 2010; 7:598-605. [PMID: 20059376 DOI: 10.1089/adt.2009.0221] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Identification of kinase, especially protein kinase, modulators through high-throughput screening (HTS) has become a common strategy for drug discovery programs in both academia and the pharmaceutical industry. There are a number of platform technologies that can be used for measuring kinase activities. However, there is none that fits all criteria in terms of sensitivity, ATP tolerance, robustness, throughput, and cost-effectiveness. Therefore, development of a homogeneous and robust HTS assay for some kinase targets is still challenging. We recently evaluated the ADP-Glo assay from Promega. This is a homogeneous, signal increase assay that measures ADP production from a kinase reaction by coupled enzymes that first convert ADP to ATP and subsequently quantifies ATP using luciferase in the presence of luciferin. Since the unused ATP in the reaction is depleted prior to ADP to ATP conversion, this assay shows excellent sensitivity over a wide range of ATP concentrations. We demonstrate that ADP-Glo assay can be used for 2 kinase targets that belong to different classes, and compare the results of compound profiling with SPA and FP assay technologies.
Collapse
Affiliation(s)
- Hu Li
- GlaxoSmithKline, Collegeville, Pennsylvania 19426, USA.
| | | | | | | | | | | | | |
Collapse
|
15
|
Perrin D, Frémaux C, Shutes A. Capillary microfluidic electrophoretic mobility shift assays: application to enzymatic assays in drug discovery. Expert Opin Drug Discov 2009; 5:51-63. [DOI: 10.1517/17460440903493431] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
16
|
Hong L, Quinn CM, Jia Y. Evaluating the utility of the HTRF Transcreener ADP assay technology: a comparison with the standard HTRF assay technology. Anal Biochem 2009; 391:31-8. [PMID: 19406097 DOI: 10.1016/j.ab.2009.04.033] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 04/20/2009] [Accepted: 04/22/2009] [Indexed: 01/13/2023]
Abstract
The HTRF (homogeneous time-resolved fluorescence) Transcreener ADP assay is a new kinase assay technology marketed by Cis-Bio International (Bagnols-Cèze, France). It measures kinase activity by detecting the formation of ADP using a monoclonal antibody and HTRF detection principles. In this article, we compare this technology with a standard HTRF kinase assay using EGFR [L858R/T790M] mutant enzyme as a case study. We demonstrate that the HTRF Transcreener ADP assay generated similar kinetic constants and inhibitor potency compared with the standard HTRF assay. However, the smaller dynamic window and lower Z' factor of the HTRF Transcreener ADP assay make this format less preferable for high-throughput screening. Based on the assay principle, the HTRF Transcreener ADP assay can detect both kinase and ATPase activities simultaneously. The ability to probe ATPase activity opens up new avenues for assaying kinases with intrinsic ATPase activity without the need to identify substrates, and this can speed up the drug discovery process. However, caution must be exercised because any contaminating ATPase activity will result in an invalid assay. The inability to tolerate high concentrations of ATP in the assay will also limit the application of this technology, especially in compound mechanistic studies such as ATP competition. Overall, the HTRF Transcreener ADP assay provides a new alternative tool to complement existing assay technologies for drug discovery.
Collapse
Affiliation(s)
- Lin Hong
- Department of Kinase Biology/Oncology, Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | | | | |
Collapse
|
17
|
Zhou V, Gao X, Han S, Brinker A, Caldwell JS, Gu XJ. An intracellular conformational sensor assay for Abl T315I. Anal Biochem 2008; 385:300-8. [PMID: 19059193 DOI: 10.1016/j.ab.2008.11.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 10/31/2008] [Accepted: 11/06/2008] [Indexed: 10/21/2022]
Abstract
Conformational change is a common molecular mechanism for the regulation of kinase activities. Small molecule modulators of protein conformations, including allosteric kinase inhibitors, are highly wanted as tools for the interrogation of kinase biology and as selective therapeutic agents. However, straightforward cellular assays monitoring kinase conformations in a manner conducive to high-throughput screening (HTS) are not readily available. Here we describe such an HTS-compatible conformational sensor assay for Abl based on a split luciferase construct. The Abl sensor responds to intramolecular structural rearrangements associated with intracellular Abl deactivation and small molecule inhibition. The intact regulatory CAP-SH3-SH2 domain is required for the full functionality of the sensor. Moreover, a T334I Abl mutant (T315I in Abl1a) was found to be particularly well suited for HTS purposes and mechanistic intracellular studies of T334I mutant inhibitors. We expect that the split luciferase-based conformational sensor approach might be more broadly useful to probe the intracellular activation of other kinases and enzymes in general.
Collapse
Affiliation(s)
- Vicki Zhou
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | | | | | | | | | | |
Collapse
|