1
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Krishnan SR, Bung N, Srinivasan R, Roy A. Target-specific novel molecules with their recipe: Incorporating synthesizability in the design process. J Mol Graph Model 2024; 129:108734. [PMID: 38442440 DOI: 10.1016/j.jmgm.2024.108734] [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] [Received: 12/03/2023] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 03/07/2024]
Abstract
Application of Artificial intelligence (AI) in drug discovery has led to several success stories in recent times. While traditional methods mostly relied upon screening large chemical libraries for early-stage drug-design, de novo design can help identify novel target-specific molecules by sampling from a much larger chemical space. Although this has increased the possibility of finding diverse and novel molecules from previously unexplored chemical space, this has also posed a great challenge for medicinal chemists to synthesize at least some of the de novo designed novel molecules for experimental validation. To address this challenge, in this work, we propose a novel forward synthesis-based generative AI method, which is used to explore the synthesizable chemical space. The method uses a structure-based drug design framework, where the target protein structure and a target-specific seed fragment from co-crystal structures can be the initial inputs. A random fragment from a purchasable fragment library can also be the input if a target-specific fragment is unavailable. Then a template-based forward synthesis route prediction and molecule generation is performed in parallel using the Monte Carlo Tree Search (MCTS) method where, the subsequent fragments for molecule growth can again be obtained from a purchasable fragment library. The rewards for each iteration of MCTS are computed using a drug-target affinity (DTA) model based on the docking pose of the generated reaction intermediates at the binding site of the target protein of interest. With the help of the proposed method, it is now possible to overcome one of the major obstacles posed to the AI-based drug design approaches through the ability of the method to design novel target-specific synthesizable molecules.
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Affiliation(s)
| | - Navneet Bung
- TCS Research (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, 500081, India
| | - Rajgopal Srinivasan
- TCS Research (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, 500081, India
| | - Arijit Roy
- TCS Research (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, 500081, India.
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2
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Deactivatable Bisubstrate Inhibitors of Protein Kinases. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27196689. [PMID: 36235226 PMCID: PMC9573699 DOI: 10.3390/molecules27196689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/26/2022] [Accepted: 10/06/2022] [Indexed: 11/08/2022]
Abstract
Bivalent ligands, including bisubstrate inhibitors, are conjugates of pharmacophores, which simultaneously target two binding sites of the biomolecule. Such structures offer attainable means for the development of compounds whose ability to bind to the biological target could be modulated by an external trigger. In the present work, two deactivatable bisubstrate inhibitors of basophilic protein kinases (PKs) were constructed by conjugating the pharmacophores via linkers that could be cleaved in response to external stimuli. The inhibitor ARC-2121 incorporated a photocleavable nitrodibenzofuran-comprising β-amino acid residue in the structure of the linker. The pharmacophores of the other deactivatable inhibitor ARC-2194 were conjugated via reduction-cleavable disulfide bond. The disassembly of the inhibitors was monitored by HPLC-MS. The affinity and inhibitory potency of the inhibitors toward cAMP-dependent PK (PKAcα) were established by an equilibrium competitive displacement assay and enzyme activity assay, respectively. The deactivatable inhibitors possessed remarkably high 1-2-picomolar affinity toward PKAcα. Irradiation of ARC-2121 with 365 nm UV radiation led to reaction products possessing a 30-fold reduced affinity. The chemical reduction of ARC-2194 resulted in the decrease of affinity of over four orders of magnitude. The deactivatable inhibitors of PKs are valuable tools for the temporal inhibition or capture of these pharmacologically important enzymes.
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3
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Nonga OE, Enkvist E, Herberg FW, Uri A. Inhibitors and fluorescent probes for protein kinase PKAcβ and its S54L mutant, identified in a patient with cortisol producing adenoma. Biosci Biotechnol Biochem 2020; 84:1839-1845. [DOI: 10.1080/09168451.2020.1772038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Abstract
Recently, a mutation was discovered in the gene PRKACB encoding the catalytic subunit β of PKA (PKAcβ) from a patient with severe Cushing’s syndrome. This mutation, S54L, leads to a structural change in the glycine-rich loop of the protein. In the present study, an inhibitor with six-fold selectivity toward S54L-PKAcβ mutant over the wild-type enzyme was constructed. Moreover, we developed a fluorescent assay allowing to determine side by side the affinity of commercially available PKA inhibitors, newly synthesized compounds, and fluorescent probes toward PKAcβ and S54L-PKAcβ.
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Affiliation(s)
| | - Erki Enkvist
- Institute of Chemistry, University of Tartu, Tartu, Estonia
| | | | - Asko Uri
- Institute of Chemistry, University of Tartu, Tartu, Estonia
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4
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Manschwetus JT, Bendzunas GN, Limaye AJ, Knape MJ, Herberg FW, Kennedy EJ. A Stapled Peptide Mimic of the Pseudosubstrate Inhibitor PKI Inhibits Protein Kinase A. Molecules 2019; 24:molecules24081567. [PMID: 31009996 PMCID: PMC6514771 DOI: 10.3390/molecules24081567] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 04/17/2019] [Accepted: 04/19/2019] [Indexed: 11/16/2022] Open
Abstract
Kinases regulate multiple and diverse signaling pathways and misregulation is implicated in a multitude of diseases. Although significant efforts have been put forth to develop kinase-specific inhibitors, specificity remains a challenge. As an alternative to catalytic inhibition, allosteric inhibitors can target areas on the surface of an enzyme, thereby providing additional target diversity. Using cAMP-dependent protein kinase A (PKA) as a model system, we sought to develop a hydrocarbon-stapled peptide targeting the pseudosubstrate domain of the kinase. A library of peptides was designed from a Protein Kinase Inhibitor (PKI), a naturally encoded protein that serves as a pseudosubstrate inhibitor for PKA. The binding properties of these peptide analogs were characterized by fluorescence polarization and surface plasmon resonance, and two compounds were identified with KD values in the 500-600 pM range. In kinase activity assays, both compounds demonstrated inhibition with 25-35 nM IC50 values. They were also found to permeate cells and localize within the cytoplasm and inhibited PKA activity within the cellular environment. To the best of our knowledge, these stapled peptide inhibitors represent some of the highest affinity binders reported to date for hydrocarbon stapled peptides.
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Affiliation(s)
- Jascha T Manschwetus
- Department of Biochemistry, Institute for Biology, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany.
| | - George N Bendzunas
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, 240 W. Green St, Athens, GA 30602, USA.
| | - Ameya J Limaye
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, 240 W. Green St, Athens, GA 30602, USA.
| | - Matthias J Knape
- Department of Biochemistry, Institute for Biology, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany.
| | - Friedrich W Herberg
- Department of Biochemistry, Institute for Biology, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany.
| | - Eileen J Kennedy
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, 240 W. Green St, Athens, GA 30602, USA.
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5
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Binding assay for characterization of protein kinase inhibitors possessing sub-picomolar to sub-millimolar affinity. Anal Biochem 2017; 531:67-77. [DOI: 10.1016/j.ab.2017.05.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 05/16/2017] [Indexed: 02/06/2023]
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6
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Ivan T, Enkvist E, Sinijarv H, Uri A. Competitive ligands facilitate dissociation of the complex of bifunctional inhibitor and protein kinase. Biophys Chem 2017. [PMID: 28651101 DOI: 10.1016/j.bpc.2017.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Dissociation of the complex of a ligand and a protein usually follows the kinetic profile of the first order process and the rate of dissociation is not affected by the presence of competitive ligands. We discovered that dissociation of the complex between a bifunctional ligand and a protein kinase (the catalytic subunit of cAMP-dependent protein kinase), an enzyme possessing 2 different substrate binding sites, was accelerated (facilitated) over 50-fold in the presence of competitive ligands at higher concentrations. Structurally diverse compounds revealed >10-fold different efficiency for acceleration of dissociation of the complex. These results show that the kinetic behavior of flexible biomolecular complexes possessing two spatially separated contact areas is highly dynamic. This property of biomolecular complexes should be carefully considered for effective application of bifunctional ligands for regulation of activity of target proteins in cells.
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Affiliation(s)
- Taavi Ivan
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Erki Enkvist
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Hedi Sinijarv
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Asko Uri
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia.
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7
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Ivan T, Enkvist E, Viira B, Manoharan GB, Raidaru G, Pflug A, Alam KA, Zaccolo M, Engh RA, Uri A. Bifunctional Ligands for Inhibition of Tight-Binding Protein-Protein Interactions. Bioconjug Chem 2016; 27:1900-10. [PMID: 27389935 DOI: 10.1021/acs.bioconjchem.6b00293] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The acknowledged potential of small-molecule therapeutics targeting disease-related protein-protein interactions (PPIs) has promoted active research in this field. The strategy of using small molecule inhibitors (SMIs) to fight strong (tight-binding) PPIs tends to fall short due to the flat and wide interfaces of PPIs. Here we propose a biligand approach for disruption of strong PPIs. The potential of this approach was realized for disruption of the tight-binding (KD = 100 pM) tetrameric holoenzyme of cAMP-dependent protein kinase (PKA). Supported by X-ray analysis of cocrystals, bifunctional inhibitors (ARC-inhibitors) were constructed that simultaneously associated with both the ATP-pocket and the PPI interface area of the catalytic subunit of PKA (PKAc). Bifunctional inhibitor ARC-1411, possessing a KD value of 3 pM toward PKAc, induced the dissociation of the PKA holoenzyme with a low-nanomolar IC50, whereas the ATP-competitive inhibitor H89 bound to the PKA holoenzyme without disruption of the protein tetramer.
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Affiliation(s)
- Taavi Ivan
- Institute of Chemistry, University of Tartu , 50410 Tartu, Estonia
| | - Erki Enkvist
- Institute of Chemistry, University of Tartu , 50410 Tartu, Estonia
| | - Birgit Viira
- Institute of Chemistry, University of Tartu , 50410 Tartu, Estonia
| | | | - Gerda Raidaru
- Institute of Chemistry, University of Tartu , 50410 Tartu, Estonia
| | - Alexander Pflug
- The Norwegian Structural Biology Centre, Department of Chemistry, University of Tromsø , N-9019 Tromsø, Norway
| | - Kazi Asraful Alam
- The Norwegian Structural Biology Centre, Department of Chemistry, University of Tromsø , N-9019 Tromsø, Norway
| | - Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford , OX1 3QX Oxford, United Kingdom
| | - Richard Alan Engh
- The Norwegian Structural Biology Centre, Department of Chemistry, University of Tromsø , N-9019 Tromsø, Norway
| | - Asko Uri
- Institute of Chemistry, University of Tartu , 50410 Tartu, Estonia
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8
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Breen ME, Soellner MB. Small molecule substrate phosphorylation site inhibitors of protein kinases: approaches and challenges. ACS Chem Biol 2015; 10:175-89. [PMID: 25494294 PMCID: PMC4301090 DOI: 10.1021/cb5008376] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Protein kinases are
important mediators of cellular communication
and attractive drug targets for many diseases. Although success has
been achieved with developing ATP-competitive kinase inhibitors, the
disadvantages of ATP-competitive inhibitors have led to increased
interest in targeting sites outside of the ATP binding pocket. Kinase
inhibitors with substrate-competitive, ATP-noncompetitive binding
modes are promising due to the possibility of increased selectivity
and better agreement between biochemical and in vitro potency. However, the difficulty of identifying these types of inhibitors
has resulted in significantly fewer small molecule substrate phosphorylation
site inhibitors being reported compared to ATP-competitive inhibitors.
This review surveys reported substrate phosphorylation site inhibitors
and methods that can be applied to the discovery of such inhibitors,
including a discussion of the challenges inherent to these screening
methods.
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Affiliation(s)
- Meghan E. Breen
- Department of Medicinal Chemistry and ‡Department of
Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Matthew B. Soellner
- Department of Medicinal Chemistry and ‡Department of
Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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9
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Kriisa M, Sinijärv H, Vaasa A, Enkvist E, Kostenko S, Moens U, Uri A. Inhibition of CREB Phosphorylation by Conjugates of Adenosine Analogues and Arginine-Rich Peptides, Inhibitors of PKA Catalytic Subunit. Chembiochem 2014; 16:312-9. [DOI: 10.1002/cbic.201402526] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Indexed: 01/05/2023]
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10
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Lei C, Xu X, Zhou J, Liu X, Nie Z, Qing M, Li P, Huang Y, Yao S. A Mix-and-Read Fluorescence Strategy for the Switch-On Probing of Kinase Activity Based on an Aptameric-Peptide/Graphene-Oxide Platform. Chem Asian J 2014; 9:2560-7. [DOI: 10.1002/asia.201402221] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Indexed: 11/08/2022]
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11
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Oshiro S, Honda S. Imparting albumin-binding affinity to a human protein by mimicking the contact surface of a bacterial binding protein. ACS Chem Biol 2014; 9:1052-60. [PMID: 24533528 DOI: 10.1021/cb400946m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Attachment of a bacterial albumin-binding protein module is an attractive strategy for extending the plasma residence time of protein therapeutics. However, a protein fused with such a bacterial module could induce unfavorable immune reactions. To address this, we designed an alternative binding protein by imparting albumin-binding affinity to a human protein using molecular surface grafting. The result was a series of human-derived 6 helix-bundle proteins, one of which specifically binds to human serum albumin (HSA) with adequate affinity (KD = 100 nM). The proteins were designed by transferring key binding residues of a bacterial albumin-binding module, Finegoldia magna protein G-related albumin-binding domain (GA) module, onto the human protein scaffold. Despite 13-15 mutations, the designed proteins maintain the original secondary structure by virtue of careful grafting based on structural informatics. Competitive binding assays and thermodynamic analyses of the best binders show that the binding mode resembles that of the GA module, suggesting that the contacting surface of the GA module is mimicked well on the designed protein. These results indicate that the designed protein may act as an alternative low-risk binding module to HSA. Furthermore, molecular surface grafting in combination with structural informatics is an effective approach for avoiding deleterious mutations on a target protein and for imparting the binding function of one protein onto another.
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Affiliation(s)
- Satoshi Oshiro
- Department
of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Shinya Honda
- Department
of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
- Biomedical
Research Institute, National Institute of Advanced Industrial Science and Technology, Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
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12
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Zhou J, Xu X, Liu X, Li H, Nie Z, Qing M, Huang Y, Yao S. A gold nanoparticles colorimetric assay for label-free detection of protein kinase activity based on phosphorylation protection against exopeptidase cleavage. Biosens Bioelectron 2013; 53:295-300. [PMID: 24157613 DOI: 10.1016/j.bios.2013.09.070] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 09/17/2013] [Accepted: 09/26/2013] [Indexed: 11/20/2022]
Abstract
Protein kinases are significant regulators in the cell signaling pathways, and it is still greatly desirable to achieve simple and quick kinase detection. Herein, we present a novel colorimetric gold nanoparticles (AuNPs)/peptide platform for probing the activity and inhibition of protein kinases based on phosphorylation-induced suppression of carboxypeptidase Y (CPY) cleavage. This AuNPs/peptide platform can easily monitor the kinase activity by a UV-vis spectrometer or even by the naked eye. The feasibility of the method has been demonstrated by sensitive measurement of the cAMP-dependent protein kinase (PKA) activity with a low detection limit of 0.232 mU/µL and assessment of kinase inhibition by H-89 with an IC50 value of 18.13 nM. The assay was also successfully put into practice for the detection of kinase activity in cell lysate. Because of its label-free, homogenous and colorimetric merits, the proposed assay presents great potential in high-throughput screening for kinase-targeted drug discovery.
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Affiliation(s)
- Jiang Zhou
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China
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13
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Fluorescent detection of protein kinase based on zirconium ions-immobilized magnetic nanoparticles. Anal Chim Acta 2013; 780:89-94. [DOI: 10.1016/j.aca.2013.03.070] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/24/2013] [Accepted: 03/26/2013] [Indexed: 12/23/2022]
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14
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Chen Z, He X, Wang Y, Wang K, Du Y, Yan G. Ru(II) encapsulated phosphorylate-terminated silica nanoparticles-based electrochemiluminescent strategy for label-free assay of protein kinase activity and inhibition. Biosens Bioelectron 2013; 41:519-25. [DOI: 10.1016/j.bios.2012.09.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 09/08/2012] [Accepted: 09/12/2012] [Indexed: 10/27/2022]
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15
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Li Y, Syed L, Liu J, Hua DH, Li J. Label-free electrochemical impedance detection of kinase and phosphatase activities using carbon nanofiber nanoelectrode arrays. Anal Chim Acta 2012; 744:45-53. [PMID: 22935373 PMCID: PMC3432243 DOI: 10.1016/j.aca.2012.07.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 07/17/2012] [Accepted: 07/18/2012] [Indexed: 11/28/2022]
Abstract
We demonstrate the feasibility of a label-free electrochemical method to detect the kinetics of phosphorylation and dephosphorylation of surface-attached peptides catalyzed by kinase and phosphatase, respectively. The peptides with a sequence specific to c-Src tyrosine kinase and protein tyrosine phosphatase 1B (PTP1B) were first validated with ELISA-based protein tyrosine kinase assay and then functionalized on vertically aligned carbon nanofiber (VACNF) nanoelectrode arrays (NEAs). Real-time electrochemical impedance spectroscopy (REIS) measurements showed reversible impedance changes upon the addition of c-Src kinase and PTP1B phosphatase. Only a small and unreliable impedance variation was observed during the peptide phosphorylation, but a large and fast impedance decrease was observed during the peptide dephosphorylation at different PTP1B concentrations. The REIS data of dephosphorylation displayed a well-defined exponential decay following the Michaelis-Menten heterogeneous enzymatic model with a specific constant, k(cat)/K(m), of (2.1±0.1)×10(7) M(-1)s(-1). Consistent values of the specific constant was measured at PTP1B concentration varying from 1.2 to 2.4 nM with the corresponding electrochemical signal decay constant varying from 38.5 to 19.1s. This electrochemical method can be potentially used as a label-free method for profiling enzyme activities in fast reactions.
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Affiliation(s)
- Yifen Li
- Department of Chemistry, Kansas State University, Manhattan, KS 66506, USA
| | - Lateef Syed
- Department of Chemistry, Kansas State University, Manhattan, KS 66506, USA
| | - Jianwei Liu
- Department of Chemistry, Kansas State University, Manhattan, KS 66506, USA
| | - Duy H. Hua
- Department of Chemistry, Kansas State University, Manhattan, KS 66506, USA
| | - Jun Li
- Department of Chemistry, Kansas State University, Manhattan, KS 66506, USA
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16
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Time-gated luminescence assay using nonmetal probes for determination of protein kinase activity-based disease markers. Anal Biochem 2012; 422:79-88. [DOI: 10.1016/j.ab.2011.12.048] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 12/15/2011] [Accepted: 12/29/2011] [Indexed: 02/01/2023]
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17
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Enkvist E, Vaasa A, Kasari M, Kriisa M, Ivan T, Ligi K, Raidaru G, Uri A. Protein-induced long lifetime luminescence of nonmetal probes. ACS Chem Biol 2011; 6:1052-62. [PMID: 21776959 DOI: 10.1021/cb200120v] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Time-resolved luminometry-based assays have great potential for measurements in complicated biological solutions and living cells as the measured signal can be easily distinguished from nanosecond lifetime background fluorescence of organic compounds and autofluorescence of cells. In the present study we discovered that binding of a thiophene- or a selenophene-containing heteroaromatic moiety (luminescence donor) to the purine-binding pocket of a protein kinase (PK) induces long lifetime photoluminescence signal that is largely intensified through efficient energy transfer to a fluorescent dye present in close proximity to the luminescence donor. The developed ARC-Lum probes possessing 19-266 μs luminescence lifetime when associated with the target kinase can be used for determination of activity of basophilic PKs, characterization of inhibitors of PKs, and as cAMP sensors. An ARC-Lum probe was also used for the determination of kinetic parameters of inhibitor binding to the catalytic subunit of protein kinase A (PKAc). Effective real-time monitoring of the activation of PKA by Forskolin and the displacement of an ARC-Lum probe from its complex with PKA by inhibitor H89 was performed in live cells. The discovered phenomenon, protein-induced long lifetime luminescence of aromatic probes is very likely to occur with all PKs and many other proteins.
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Affiliation(s)
- Erki Enkvist
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Angela Vaasa
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Marje Kasari
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Marie Kriisa
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Taavi Ivan
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Kadri Ligi
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Gerda Raidaru
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
| | - Asko Uri
- Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia
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18
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Xu X, Liu X, Nie Z, Pan Y, Guo M, Yao S. Label-Free Fluorescent Detection of Protein Kinase Activity Based on the Aggregation Behavior of Unmodified Quantum Dots. Anal Chem 2010; 83:52-9. [DOI: 10.1021/ac102786c] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Xiahong Xu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China
| | - Xin Liu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China
| | - Zhou Nie
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China
| | - Yuliang Pan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China
| | - Manli Guo
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China
| | - Shouzhuo Yao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China
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19
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Lavogina D, Nickl CK, Enkvist E, Raidaru G, Lust M, Vaasa A, Uri A, Dostmann WR. Adenosine analogue-oligo-arginine conjugates (ARCs) serve as high-affinity inhibitors and fluorescence probes of type I cGMP-dependent protein kinase (PKGIalpha). BIOCHIMICA ET BIOPHYSICA ACTA 2010; 1804:1857-68. [PMID: 20406699 PMCID: PMC3071016 DOI: 10.1016/j.bbapap.2010.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 04/12/2010] [Accepted: 04/13/2010] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Type I cGMP-dependent protein kinase (PKGIalpha) belongs to the family of cyclic nucleotide-dependent protein kinases and is one of the main effectors of cGMP. PKGIalpha is involved in regulation of cardiac contractility, vasorelaxation, and blood pressure; hence, the development of potent modulators of PKGIalpha would lead to advances in the treatment of a variety of cardiovascular diseases. AIM Representatives of ARC-type compounds previously characterized as potent inhibitors and high-affinity fluorescent probes of PKA catalytic subunit (PKAc) were tested towards PKGIalpha to determine that ARCs could serve as activity regulators and sensors for the latter protein kinase both in vitro and in complex biological systems. RESULTS Structure-activity profiling of ARCs with PKGIalpha in vitro demonstrated both similarities as well as differences to corresponding profiling with PKAc, whereas ARC-903 and ARC-668 revealed low nanomolar displacement constants and inhibition IC(50) values with both cyclic nucleotide-dependent kinases. The ability of ARC-based fluorescent probes to penetrate cell plasma membrane was demonstrated in the smooth muscle tissue of rat cerebellum isolated arteries, and the compound with the highest affinity in vitro (ARC-903) showed also potential for in vivo applications, fully abolishing the PKG1alpha-induced vasodilation.
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Affiliation(s)
- Darja Lavogina
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Christian K. Nickl
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, VT 05405, USA
| | - Erki Enkvist
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Gerda Raidaru
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Marje Lust
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Angela Vaasa
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Asko Uri
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Wolfgang R. Dostmann
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, VT 05405, USA
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Vaasa A, Lust M, Terrin A, Uri A, Zaccolo M. Small-molecule FRET probes for protein kinase activity monitoring in living cells. Biochem Biophys Res Commun 2010; 397:750-5. [PMID: 20541535 DOI: 10.1016/j.bbrc.2010.06.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 06/07/2010] [Indexed: 01/11/2023]
Abstract
In this study, the applicability of fluorescently labeled adenosine analogue-oligoarginine conjugates (ARC-Photo probes) for monitoring of protein kinase A (PKA) activity in living cells was demonstrated. ARC-Photo probes possessing subnanomolar affinity towards the catalytic subunit of PKA (PKAc) and competitive with the regulatory subunit (PKAr), penetrate cell plasma membrane and associate with PKAc fused with yellow fluorescent protein (PKAc-YFP). Detection of inter-molecular Förster resonance energy transfer (FRET) efficiency between the fluorophores of the fusion protein and ARC-Photo probe can be used for both the evaluation of non-labeled inhibitors of PKAc and for monitoring of cAMP signaling via detection of changes in the activity of PKA as a cAMP downstream effector.
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Affiliation(s)
- Angela Vaasa
- Institute of Chemistry, University of Tartu, 50411 Tartu, Estonia
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Lavogina D, Enkvist E, Uri A. Bisubstrate inhibitors of protein kinases: from principle to practical applications. ChemMedChem 2010; 5:23-34. [PMID: 19774589 DOI: 10.1002/cmdc.200900252] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Bisubstrate inhibitors consist of two conjugated fragments, each targeted to a different binding site of a bisubstrate enzyme. The design of bisubstrate inhibitors presupposes the formation of the ternary complex in the course of the catalyzed reaction. The principle advantage of bisubstrate inhibitors is their ability to generate more interactions with the target enzyme that could result in improved affinity and selectivity of the conjugates, when compared with single-site inhibitors. Among phosphotransferases, the approach was first successfully used for adenylate kinase in 1973. Since then, several types of bisubstrate inhibitors have been developed for protein kinases, including conjugates of peptides with nucleotides, adenosine derivatives and potent ATP-competitive inhibitors. Earlier bisubstrate inhibitors had pharmacokinetic qualities that were unsuitable for cellular experiments and hence were mostly used for in vitro studies. The recently constructed conjugates of adenosine derivatives and D-arginine-rich peptides (ARCs) possess high kinase affinity, high biological and chemical stability and good cell plasma membrane penetrative properties that enable their application in the regulation of cellular protein phosphorylation balances in cell and tissue experiments.
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Affiliation(s)
- Darja Lavogina
- Institute of Chemistry, Jakobi 2, 51014 Tartu (Estonia).
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Bisubstrate fluorescent probes and biosensors in binding assays for HTS of protein kinase inhibitors. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:541-6. [DOI: 10.1016/j.bbapap.2009.10.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 10/18/2009] [Accepted: 10/21/2009] [Indexed: 11/20/2022]
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Chin KH, Lee YC, Tu ZL, Chen CH, Tseng YH, Yang JM, Ryan RP, McCarthy Y, Dow JM, Wang AHJ, Chou SH. The cAMP receptor-like protein CLP is a novel c-di-GMP receptor linking cell-cell signaling to virulence gene expression in Xanthomonas campestris. J Mol Biol 2009; 396:646-62. [PMID: 20004667 DOI: 10.1016/j.jmb.2009.11.076] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 11/23/2009] [Accepted: 11/24/2009] [Indexed: 01/01/2023]
Abstract
Cyclic-di-GMP [bis-(3'-5')-cyclic diguanosine monophosphate] controls a wide range of functions in eubacteria, yet little is known about the underlying regulatory mechanisms. In the plant pathogen Xanthomonas campestris, expression of a subset of virulence genes is regulated by c-di-GMP and also by the CAP (catabolite activation protein)-like protein XcCLP, a global regulator in the CRP/FNR superfamily. Here, we report structural and functional insights into the interplay between XcCLP and c-di-GMP in regulation of gene expression. XcCLP bound target promoter DNA with submicromolar affinity in the absence of any ligand. This DNA-binding capability was abrogated by c-di-GMP, which bound to XcCLP with micromolar affinity. The crystal structure of XcCLP showed that the protein adopted an intrinsically active conformation for DNA binding. Alteration of residues of XcCLP implicated in c-di-GMP binding through modeling studies caused a substantial reduction in binding affinity for the nucleotide and rendered DNA binding by these variant proteins insensitive to inhibition by c-di-GMP. Together, these findings reveal the structural mechanism behind a novel class of c-di-GMP effector proteins in the CRP/FNR superfamily and indicate that XcCLP regulates bacterial virulence gene expression in a manner negatively controlled by the c-di-GMP concentrations.
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Affiliation(s)
- Ko-Hsin Chin
- Institute of Biochemistry, National Chung-Hsing University, Taichung 40227, Taiwan, ROC
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Effect of the structure of adenosine mimic of bisubstrate-analog inhibitors on their activity towards basophilic protein kinases. Bioorg Med Chem Lett 2009; 19:6098-101. [PMID: 19800227 DOI: 10.1016/j.bmcl.2009.09.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 09/04/2009] [Accepted: 09/05/2009] [Indexed: 11/20/2022]
Abstract
Previously reported structural fragments that associate with the ATP-binding pocket of basophilic protein kinases were conjugated with d-arginine-containing peptides. Inhibitory potency of the resulting bisubstrate-analog inhibitors towards PKA and ROCK-II extended to subnanomolar range. The conjugates incorporating 2-pyrimidyl-5-amidothiophene fragment had the highest activity and at 100 nM concentration exhibited over 80% inhibition of most of the tested basophilic kinases of the AGC group.
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Kerman K, Kraatz HB. Electrochemical detection of protein tyrosine kinase-catalysed phosphorylation using gold nanoparticles. Biosens Bioelectron 2009; 24:1484-9. [DOI: 10.1016/j.bios.2008.10.024] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 10/24/2008] [Accepted: 10/27/2008] [Indexed: 12/01/2022]
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Lavogina D, Lust M, Viil I, König N, Raidaru G, Rogozina J, Enkvist E, Uri A, Bossemeyer D. Structural Analysis of ARC-Type Inhibitor (ARC-1034) Binding to Protein Kinase A Catalytic Subunit and Rational Design of Bisubstrate Analogue Inhibitors of Basophilic Protein Kinases. J Med Chem 2008; 52:308-21. [DOI: 10.1021/jm800797n] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Darja Lavogina
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Marje Lust
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Indrek Viil
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Norbert König
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Gerda Raidaru
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Jevgenia Rogozina
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Erki Enkvist
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Asko Uri
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Dirk Bossemeyer
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
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Rich RL, Myszka DG. Survey of the year 2007 commercial optical biosensor literature. J Mol Recognit 2008; 21:355-400. [DOI: 10.1002/jmr.928] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Vaasa A, Viil I, Enkvist E, Viht K, Raidaru G, Lavogina D, Uri A. High-affinity bisubstrate probe for fluorescence anisotropy binding/displacement assays with protein kinases PKA and ROCK. Anal Biochem 2008; 385:85-93. [PMID: 19017524 DOI: 10.1016/j.ab.2008.10.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 10/03/2008] [Accepted: 10/15/2008] [Indexed: 10/21/2022]
Abstract
The bisubstrate fluorescent probe ARC-583 (Adc-Ahx-(D-Arg)(6)-d-Lys(5-TAMRA)-NH2) and its application for the characterization of both ATP- and protein/peptide substrate-competitive inhibitors of protein kinases PKA (cyclic AMP-dependent protein kinase) and ROCK (rho kinase) in fluorescence polarization-based assay are described. High affinity of the probe (K(D)=0.48 nM toward PKA) enables its application for the characterization of inhibitors with nanomolar and micromolar potency and determination of the active concentration of the kinase in individual experiments as well as in the high-throughput screening format. The probe can be used for the assessment of protein-protein interactions (e.g., between regulatory and catalytic subunits of PKA) and as a cyclic AMP biosensor.
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Affiliation(s)
- Angela Vaasa
- Institute of Chemistry, University of Tartu, 2 Jakobi St., 51014 Tartu, Estonia
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Sopko R, Andrews BJ. Linking the kinome and phosphorylome--a comprehensive review of approaches to find kinase targets. MOLECULAR BIOSYSTEMS 2008; 4:920-33. [PMID: 18704230 DOI: 10.1039/b801724g] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Protein phosphorylation is associated with most cell signaling and developmental processes in eukaryotes. Despite the vast extent of the phosphoproteome within the cell, connecting specific kinases with relevant targets remains a significant experimental frontier. The challenge of linking kinases and their substrates reflects the complexity of kinase function. For example, kinases tend to exert their biological effects through supernumerary, redundant phosphorylation, often on multiple protein complex components. Although these types of phosphorylation events are biologically significant, those kinases responsible are often difficult to identify. Recent methods for global analysis of protein phosphorylation promise to substantially accelerate efforts to map the dynamic phosphorylome. Here, we review both conventional methods to identify kinase targets and more comprehensive genomic and proteomic approaches to connect the kinome and phosphorylome.
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Affiliation(s)
- Richelle Sopko
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Canada
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Effect of metal ions on high-affinity binding of pseudosubstrate inhibitors to PKA. Biochem J 2008; 413:93-101. [PMID: 18373497 DOI: 10.1042/bj20071665] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Conformational control of protein kinases is an important way of modulating catalytic activity. Crystal structures of the C (catalytic) subunit of PKA (protein kinase A) in complex with physiological inhibitors and/or nucleotides suggest a highly dynamic process switching between open and more closed conformations. To investigate the underlying molecular mechanisms, SPR (surface plasmon resonance) was used for detailed binding analyses of two physiological PKA inhibitors, PKI (heat-stable protein kinase inhibitor) and a truncated form of the R (regulatory) subunit (RIalpha 92-260), in the presence of various concentrations of metals and nucleotides. Interestingly, it could be demonstrated that high-affinity binding of each pseudosubstrate inhibitor was dependent only on the concentration of divalent metal ions. At low micromolar concentrations of Mg2+ with PKI, transient interaction kinetics with fast on- and off-rates were observed, whereas at high Mg2+ concentrations the off-rate was slowed down by a factor of 200. This effect could be attributed to the second, low-affinity metal-binding site in the C subunit. In contrast, when investigating the interaction of RIalpha 92-260 with the C subunit under the same conditions, it was shown that the association rate rather than the dissociation rate was influenced by the presence of high concentrations of Mg2+. A model is presented, where the high-affinity interaction of the C subunit with pseudosubstrate inhibitors (RIalpha and PKI) is dependent on the closed, catalytically inactive conformation induced by the binding of a nucleotide complex where both of the metal-binding sites are occupied.
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Feltis BN, Sexton BA, Glenn FL, Best MJ, Wilkins M, Davis TJ. A hand-held surface plasmon resonance biosensor for the detection of ricin and other biological agents. Biosens Bioelectron 2007; 23:1131-6. [PMID: 18155516 DOI: 10.1016/j.bios.2007.11.005] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 10/17/2007] [Accepted: 11/02/2007] [Indexed: 01/16/2023]
Abstract
There is an ongoing need for field-deployable biosensor devices. We have constructed a fully self-contained, hand-held biosensor, based on the surface plasmon resonance technique. The dimensions of the sensor unit are 15 x 8 cm, the weight is 600 g and it is powered by a 9 V battery. We have characterised the responsiveness of the sensor using calibrated sucrose solutions and were able to measure changes as small as 3.3 x 10(-6) refractive index units. To demonstrate functionality of the sensor, we have prepared surfaces with an antibody fragment specific for the biological toxin ricin. We were able to detect ricin at 200 ng/mL in 10 min, which is approximately 2500 times less than the minimum lethal dose. We were also able to verify positive binding within a second 10 min window. This sensor demonstrates important steps required for the development of fully integrated, hand-held sensor devices and will form the basis of a multi-analyte system, to be developed in the near future. It also represents the first completely hand-held SPR device, not requiring external power or a computer connection to operate.
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Affiliation(s)
- B N Feltis
- CSIRO Materials Science and Engineering, Clayton, Victoria, Australia.
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Enkvist E, Raidaru G, Vaasa A, Pehk T, Lavogina D, Uri A. Carbocyclic 3'-deoxyadenosine-based highly potent bisubstrate-analog inhibitor of basophilic protein kinases. Bioorg Med Chem Lett 2007; 17:5336-9. [PMID: 17716894 DOI: 10.1016/j.bmcl.2007.08.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Revised: 08/08/2007] [Accepted: 08/08/2007] [Indexed: 11/21/2022]
Abstract
Carbocyclic analogs of 3'-deoxyadenosine were synthesized as racemates and the resulting stereoisomers were separated by chromatography on a chiral column. The conjugation of obtained compounds with hexa-(D-arginine) via 6-aminohexanoic acid linker led to a highly potent inhibitor of several basophilic protein kinases with some selectivity towards cAMP-dependent protein kinase.
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Affiliation(s)
- Erki Enkvist
- Institute of Organic and Bioorganic Chemistry, University of Tartu, 2 Jakobi Street, 51014 Tartu, Estonia
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Kerman K, Kraatz HB. Electrochemical detection of kinase-catalyzed thiophosphorylation using gold nanoparticles. Chem Commun (Camb) 2007:5019-21. [DOI: 10.1039/b713048a] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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