1
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Jones JH, Xin Z, Himmelbauer M, Dechantsreiter M, Enyedy I, Hedde J, Fang T, Coomaraswamy J, King KW, Murugan P, Santoro JC, Hesson T, Walther DM, Wei R, Zheng F, Marcotte DJ, Spilker K, Kumar PR, Liu Y, Gilfillan R, Gonzalez-Lopez de Turiso F. Discovery of Potent, Selective, and Brain-Penetrant Apoptosis Signal-Regulating Kinase 1 (ASK1) Inhibitors that Modulate Brain Inflammation In Vivo. J Med Chem 2021; 64:15402-15419. [PMID: 34653340 DOI: 10.1021/acs.jmedchem.1c01458] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Apoptosis signal-regulating kinase 1 (ASK1) is one of the key mediators of the cellular stress response that regulates inflammation and apoptosis. To probe the therapeutic value of modulating this pathway in preclinical models of neurological disease, we further optimized the profile of our previously reported inhibitor 3. This effort led to the discovery of 32, a potent (cell IC50 = 25 nM) and selective ASK1 inhibitor with suitable pharmacokinetic and brain penetration (rat Cl/Clu = 1.6/56 L/h/kg and Kp,uu = 0.46) for proof-of-pharmacology studies. Specifically, the ability of 32 to inhibit ASK1 in the central nervous system (CNS) was evaluated in a human tau transgenic (Tg4510) mouse model exhibiting elevated brain inflammation. In this study, transgenic animals treated with 32 (at 3, 10, and 30 mg/kg, BID/PO for 4 days) showed a robust reduction of inflammatory markers (e.g., IL-1β) in the cortex, thus confirming inhibition of ASK1 in the CNS.
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Affiliation(s)
- J Howard Jones
- Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Zhili Xin
- Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Martin Himmelbauer
- Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Michael Dechantsreiter
- Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Istvan Enyedy
- Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Joseph Hedde
- Acute Neurology Research Unit, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Terry Fang
- Acute Neurology Research Unit, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Janaky Coomaraswamy
- Movement Disorders Research Unit, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Kristopher W King
- Drug Metabolism and Pharmacokinetics, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Paramasivam Murugan
- Bioassays, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Joseph C Santoro
- Bioassays, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Thomas Hesson
- Bioassays, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Dirk M Walther
- Chemical Biology and Proteomics, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Ru Wei
- Chemical Biology and Proteomics, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Fengmei Zheng
- Technical Development, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Douglas J Marcotte
- Physical Biochemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Kerri Spilker
- Physical Biochemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - P Rajesh Kumar
- Physical Biochemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Ying Liu
- Drug Metabolism and Pharmacokinetics, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Rab Gilfillan
- Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
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2
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Halkina T, Henderson JL, Lin EY, Himmelbauer MK, Jones JH, Nevalainen M, Feng J, King K, Rooney M, Johnson JL, Marcotte DJ, Chodaparambil JV, Kumar PR, Patterson TA, Murugan P, Schuman E, Wong L, Hesson T, Lamore S, Bao C, Calhoun M, Certo H, Amaral B, Dillon GM, Gilfillan R, de Turiso FGL. Discovery of Potent and Brain-Penetrant Tau Tubulin Kinase 1 (TTBK1) Inhibitors that Lower Tau Phosphorylation In Vivo. J Med Chem 2021; 64:6358-6380. [PMID: 33944571 DOI: 10.1021/acs.jmedchem.1c00382] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Structural analysis of the known NIK inhibitor 3 bound to the kinase domain of TTBK1 led to the design and synthesis of a novel class of azaindazole TTBK1 inhibitors exemplified by 8 (cell IC50: 571 nM). Systematic optimization of this series of analogs led to the discovery of 31, a potent (cell IC50: 315 nM) and selective TTBK inhibitor with suitable CNS penetration (rat Kp,uu: 0.32) for in vivo proof of pharmacology studies. The ability of 31 to inhibit tau phosphorylation at the disease-relevant Ser 422 epitope was demonstrated in both a mouse hypothermia and a rat developmental model and provided evidence that modulation of this target may be relevant in the treatment of Alzheimer's disease and other tauopathies.
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Affiliation(s)
- Tamara Halkina
- Department of Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Jaclyn L Henderson
- Department of Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Edward Y Lin
- Department of Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Martin K Himmelbauer
- Department of Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - J Howard Jones
- Department of Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Marta Nevalainen
- Department of Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Jun Feng
- Department of Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Kristopher King
- Department of Drug Metabolism and Pharmacokinetics, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Michael Rooney
- Department of Drug Metabolism and Pharmacokinetics, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Joshua L Johnson
- Department of Drug Metabolism and Pharmacokinetics, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Douglas J Marcotte
- Department of Physical Biochemistry and Molecular Design, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Jayanth V Chodaparambil
- Department of Physical Biochemistry and Molecular Design, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - P Rajesh Kumar
- Department of Physical Biochemistry and Molecular Design, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Thomas A Patterson
- Department of Physical Biochemistry and Molecular Design, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Paramasivam Murugan
- Department of Bioassays, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Eli Schuman
- Department of Bioassays, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - LaiYee Wong
- Department of Bioassays, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Thomas Hesson
- Department of Bioassays, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Sarah Lamore
- Department of Preclinical Safety, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Channa Bao
- Department of Emerging Neurosciences Research Unit, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Michael Calhoun
- Department of Emerging Neurosciences Research Unit, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Hannah Certo
- Department of Emerging Neurosciences Research Unit, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Brenda Amaral
- Department of Emerging Neurosciences Research Unit, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Gregory M Dillon
- Department of Emerging Neurosciences Research Unit, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Rab Gilfillan
- Department of Medicinal Chemistry, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States
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3
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Xin Z, Himmelbauer MK, Jones JH, Enyedy I, Gilfillan R, Hesson T, King K, Marcotte DJ, Murugan P, Santoro JC, Gonzalez-Lopez de Turiso F. Discovery of CNS-Penetrant Apoptosis Signal-Regulating Kinase 1 (ASK1) Inhibitors. ACS Med Chem Lett 2020; 11:485-490. [PMID: 32292554 DOI: 10.1021/acsmedchemlett.9b00611] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/12/2020] [Indexed: 02/07/2023] Open
Abstract
Apoptosis signal-regulating kinase 1 (ASK1) is a key mediator in the apoptotic and inflammatory cellular stress response. To investigate the therapeutic value of modulating this pathway in neurological disease, we have completed medicinal chemistry studies to identify novel CNS-penetrant ASK1 inhibitors starting from peripherally restricted compounds reported in the literature. This effort led to the discovery of 21, a novel ASK1 inhibitor with good potency (cell IC50 = 138 nM), low clearance (rat Cl/Clu = 0.36/6.7 L h-1 kg-1) and good CNS penetration (rat K p,uu = 0.38).
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4
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Marcotte DJ, Spilker KA, Wen D, Hesson T, Patterson TA, Kumar PR, Chodaparambil JV. The crystal structure of the catalytic domain of tau tubulin kinase 2 in complex with a small-molecule inhibitor. Acta Crystallogr F Struct Biol Commun 2020; 76:103-108. [PMID: 32133995 DOI: 10.1107/s2053230x2000031x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/12/2020] [Indexed: 08/24/2023]
Abstract
Tau proteins play an important role in the proper assembly and function of neurons. Hyperphosphorylation of tau by kinases such as tau tubulin kinase (TTBK) has been hypothesized to cause the aggregation of tau and the formation of neurofibrillary tangles (NFTs) that lead to the destabilization of microtubules, thereby contributing to neurodegenerative diseases such as Alzheimer's disease (AD). There are two TTBK isoforms with highly homologous catalytic sites but with distinct tissue distributions, tau phosphorylation patterns and loss-of-function effects. Inhibition of TTBK1 reduces the levels of NFT formation involved in neurodegenerative diseases such as AD, whereas inhibition of TTBK2 may lead to the movement disorder spinocerebellar ataxia type 11 (SCA11). Hence, it is critical to obtain isoform-selective inhibitors. Structure-based drug design (SBDD) has been used to design highly potent and exquisitely selective inhibitors. While structures of TTBK1 have been reported in the literature, TTBK2 has evaded structural characterization. Here, the first crystal structure of the TTBK2 kinase domain is described. Furthermore, the crystal structure of human TTBK2 in complex with a small-molecule inhibitor has successfully been determined to elucidate the structural differences in protein conformations between the two TTBK isoforms that could aid in SBDD for the design of inhibitors that selectively target TTBK1 over TTBK2.
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Affiliation(s)
- Douglas J Marcotte
- Department of Biotherapeutics and Medicinal Sciences, Biogen, 115 Broadway, Cambridge, MA 02142, USA
| | - Kerri A Spilker
- Department of Biotherapeutics and Medicinal Sciences, Biogen, 115 Broadway, Cambridge, MA 02142, USA
| | - Dingyi Wen
- Department of Biotherapeutics and Medicinal Sciences, Biogen, 115 Broadway, Cambridge, MA 02142, USA
| | - Thomas Hesson
- Department of Biotherapeutics and Medicinal Sciences, Biogen, 115 Broadway, Cambridge, MA 02142, USA
| | - Thomas A Patterson
- Department of Biotherapeutics and Medicinal Sciences, Biogen, 115 Broadway, Cambridge, MA 02142, USA
| | - P Rajesh Kumar
- Department of Biotherapeutics and Medicinal Sciences, Biogen, 115 Broadway, Cambridge, MA 02142, USA
| | - Jayanth V Chodaparambil
- Department of Biotherapeutics and Medicinal Sciences, Biogen, 115 Broadway, Cambridge, MA 02142, USA
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5
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Himmelbauer MK, Xin Z, Jones JH, Enyedy I, King K, Marcotte DJ, Murugan P, Santoro JC, Hesson T, Spilker K, Johnson JL, Luzzio MJ, Gilfillan R, de Turiso FGL. Rational Design and Optimization of a Novel Class of Macrocyclic Apoptosis Signal-Regulating Kinase 1 Inhibitors. J Med Chem 2019; 62:10740-10756. [DOI: 10.1021/acs.jmedchem.9b01206] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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6
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May-Dracka TL, Arduini R, Bertolotti-Ciarlet A, Bhisetti G, Brickelmaier M, Cahir-McFarland E, Enyedy I, Fontenot JD, Hesson T, Little K, Lyssikatos J, Marcotte D, McKee T, Murugan P, Patterson T, Peng H, Rushe M, Silvian L, Spilker K, Wu P, Xin Z, Burkly LC. Investigating small molecules to inhibit germinal center kinase-like kinase (GLK/MAP4K3) upstream of PKCθ phosphorylation: Potential therapy to modulate T cell dependent immunity. Bioorg Med Chem Lett 2018; 28:1964-1971. [PMID: 29636220 DOI: 10.1016/j.bmcl.2018.03.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 03/02/2018] [Accepted: 03/12/2018] [Indexed: 02/03/2023]
Abstract
Germinal center kinase-like kinase (GLK, also known as MAP4K3) has been hypothesized to have an effect on key cellular activities, including inflammatory responses. GLK is required for activation of protein kinase C-θ (PKCθ) in T cells. Controlling the activity of T helper cell responses could be valuable for the treatment of autoimmune diseases. This approach circumvents previous unsuccessful approaches to target PKCθ directly. The use of structure based drug design, aided by the first crystal structure of GLK, led to the discovery of several inhibitors that demonstrate potent inhibition of GLK biochemically and in relevant cell lines.
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Affiliation(s)
- Tricia L May-Dracka
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States.
| | - Robert Arduini
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Andrea Bertolotti-Ciarlet
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Govinda Bhisetti
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Margot Brickelmaier
- Acute Neurology Research, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Ellen Cahir-McFarland
- Acute Neurology Research, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Istvan Enyedy
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Jason D Fontenot
- Acute Neurology Research, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Thomas Hesson
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Kevin Little
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Joe Lyssikatos
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Douglas Marcotte
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Timothy McKee
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Paramasivam Murugan
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Thomas Patterson
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Hairuo Peng
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Mia Rushe
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Laura Silvian
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Kerri Spilker
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Ping Wu
- Acute Neurology Research, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Zhili Xin
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
| | - Linda C Burkly
- Acute Neurology Research, Biogen, 225 Binney Street, Cambridge, MA 02142, United States
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7
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Marcotte D, Rushe M, M Arduini R, Lukacs C, Atkins K, Sun X, Little K, Cullivan M, Paramasivam M, Patterson TA, Hesson T, D McKee T, May-Dracka TL, Xin Z, Bertolotti-Ciarlet A, Bhisetti GR, Lyssikatos JP, Silvian LF. Germinal-center kinase-like kinase co-crystal structure reveals a swapped activation loop and C-terminal extension. Protein Sci 2016; 26:152-162. [PMID: 27727493 DOI: 10.1002/pro.3062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 10/10/2016] [Accepted: 10/10/2016] [Indexed: 12/20/2022]
Abstract
Germinal-center kinase-like kinase (GLK, Map4k3), a GCK-I family kinase, plays multiple roles in regulating apoptosis, amino acid sensing, and immune signaling. We describe here the crystal structure of an activation loop mutant of GLK kinase domain bound to an inhibitor. The structure reveals a weakly associated, activation-loop swapped dimer with more than 20 amino acids of ordered density at the carboxy-terminus. This C-terminal PEST region binds intermolecularly to the hydrophobic groove of the N-terminal domain of a neighboring molecule. Although the GLK activation loop mutant crystallized demonstrates reduced kinase activity, its structure demonstrates all the hallmarks of an "active" kinase, including the salt bridge between the C-helix glutamate and the catalytic lysine. Our compound displacement data suggests that the effect of the Ser170Ala mutation in reducing kinase activity is likely due to its effect in reducing substrate peptide binding affinity rather than reducing ATP binding or ATP turnover. This report details the first structure of GLK; comparison of its activation loop sequence and P-loop structure to that of Map4k4 suggests ideas for designing inhibitors that can distinguish between these family members to achieve selective pharmacological inhibitors.
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Affiliation(s)
- Douglas Marcotte
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Mia Rushe
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Robert M Arduini
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | | | - Kateri Atkins
- Beryllium Discovery Corp., 3 Preston Court, Bedford, MA, 01730
| | - Xin Sun
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Kevin Little
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Michael Cullivan
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Murugan Paramasivam
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Thomas A Patterson
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Thomas Hesson
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Timothy D McKee
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Tricia L May-Dracka
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Zhili Xin
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | | | - Govinda R Bhisetti
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Joseph P Lyssikatos
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
| | - Laura F Silvian
- Department of Drug Discovery, Biogen Inc., 115 Binney Street, Cambridge, MA, 02142
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8
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Sheth PR, Liu Y, Hesson T, Zhao J, Vilenchik L, Liu YH, Mayhood TW, Le HV. Fully activated MEK1 exhibits compromised affinity for binding of allosteric inhibitors U0126 and PD0325901. Biochemistry 2011; 50:7964-76. [PMID: 21793567 DOI: 10.1021/bi200542r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Kinases catalyze the transfer of γ-phosphate from ATP to substrate protein residues triggering signaling pathways responsible for a plethora of cellular events. Isolation and production of homogeneous preparations of kinases in their fully active forms is important for accurate in vitro measurements of activity, stability, and ligand binding properties of these proteins. Previous studies have shown that MEK1 can be produced in its active phosphorylated form by coexpression with RAF1 in insect cells. In this study, using activated MEK1 produced by in vitro activation by RAF1 (pMEK1(in vitro)), we demonstrate that the simultaneous expression of RAF1 for production of activated MEK1 does not result in stoichiometric phosphorylation of MEK1. The pMEK1(in vitro) showed higher specific activity toward ERK2 protein substrate compared to the pMEK1 that was activated via coexpression with RAF1 (pMEK1(in situ)). The two pMEK1 preparations showed quantitative differences in the phosphorylation of T-loop residue serine 222 by Western blotting and mass spectrometry. Finally, pMEK1(in vitro) showed marked differences in the ligand binding properties compared to pMEK1(in situ). Contrary to previous findings, pMEK1(in vitro) bound allosteric inhibitors U0126 and PD0325901 with a significantly lower affinity than pMEK1(in situ) as well as its unphosphorylated counterpart (npMEK1) as demonstrated by thermal-shift, AS-MS, and calorimetric studies. The differences in inhibitor binding affinity provide direct evidence that unphosphorylated and RAF1-phosphorylated MEK1 form distinct inhibitor sites.
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Affiliation(s)
- Payal R Sheth
- Protein Science Department, Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, USA.
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9
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Gesell JJ, Liu D, Madison VS, Hesson T, Wang YS, Weber PC, Wyss DF. Design, high-level expression, purification and characterization of soluble fragments of the hepatitis C virus NS3 RNA helicase suitable for NMR-based drug discovery methods and mechanistic studies. Protein Eng 2001; 14:573-82. [PMID: 11579226 DOI: 10.1093/protein/14.8.573] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
RNA helicases represent a family of enzymes that unwind double-stranded (ds) RNA in a nucleoside triphosphate (NTP)-dependent fashion and which are required in all aspects of cellular RNA metabolism and processing. The hepatitis C virus (HCV) non-structural 3 (NS3) protein possesses a serine protease activity in the N-terminal one-third, whereas RNA-stimulated NTPase and helicase activities reside in the C-terminal portion of the 631 amino acid residue bifunctional enzyme. The HCV NS3 RNA helicase is of key importance in the life cycle of HCV, which makes it a target for the development of therapeutics. However, neither the precise mechanism nor the substrate structure has been defined for this enzyme. For nuclear magnetic resonance (NMR)-based drug discovery methods and for mechanistic studies we engineered, prepared and characterized various truncated constructs of the 451-residue HCV NS3 RNA helicase. Our goal was to produce smaller fragments of the enzyme, which would be amenable to solution NMR techniques while retaining their native NTP and/or nucleic acid binding sites. Solution conditions were optimized to obtain high-quality heteronuclear NMR spectra of nitrogen-15 isotope-labeled constructs, which are typical of well-folded monomeric proteins. Moreover, NMR binding studies and functional data directly support the correct folding of these fragments.
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Affiliation(s)
- J J Gesell
- These two authors contributed equally to this work. Department of Structural Chemistry, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
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10
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Hesson T, Mannarino A, Cable M. Probing the relationship between RNA-stimulated ATPase and helicase activities of HCV NS3 using 2'-O-methyl RNA substrates. Biochemistry 2000; 39:2619-25. [PMID: 10704211 DOI: 10.1021/bi992127a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The hepatitis C virus (HCV) NS3 protein contains an amino terminal protease (NS3 aa. 1-180) and a carboxyl terminal RNA helicase (NS3 aa. 181-631). NS3 functions as a heterodimer of NS3 and NS4A (NS3/4A). NS3 helicase, a nucleic acid stimulated ATPase, can unwind RNA, DNA, and RNA:DNA duplexes, provided that at least one strand of the duplex contains a single-stranded 3' overhang (this strand of the duplex is referred to as the 3' strand). We have used 2'-O-methyl RNA (MeRNA) substrates to study the mechanism of NS3 helicase activity and to probe the relationship between its helicase and RNA-stimulated ATPase activities. NS3/4A did not unwind double-stranded (ds) MeRNA. NS3/4A unwinds hybrid RNA:MeRNA duplex containing MeRNA as the 5' strand but not hybrid duplex containing MeRNA as the 3' strand. The helicase activity of NS3/4A was 50% inhibited by 40 nM single-stranded (ss) RNA but only 35% inhibited by 320 nM ss MeRNA. Double-stranded RNA was 17 times as effective as double-stranded MeRNA in inhibiting NS3/4A helicase activity, while the apparent affinity of NS3/4A for ds MeRNA differed from ds RNA by only 2.4-fold. However ss MeRNA stimulated NS3/4A ATPase activity similar to ss RNA. These results indicate that the helicase mechanism involves 3' to 5' procession of the NS3 helicase along the 3' strand and only weak association of the enzyme with the displaced 5' strand. Further, our findings show that maximum stimulation of NS3 ATPase activity by ss nucleic acid is not directly related to procession of the helicase along the 3' strand.
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Affiliation(s)
- T Hesson
- Department of Structural Chemistry, Schering Plough Research Institute, Kenilworth, New Jersey 07033-0539, USA.
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11
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Hesson T. Ventilator repair tips. Biomed Instrum Technol 1998; 32:83. [PMID: 9475965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- T Hesson
- Thomas Jefferson University Hospital, USA
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12
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Abstract
Helicases are nucleotide triphosphate (NTP)-dependent enzymes responsible for unwinding duplex DNA and RNA during genomic replication. The 2.1 A resolution structure of the HCV helicase from the positive-stranded RNA hepatitis C virus reveals a molecule with distinct NTPase and RNA binding domains. The structure supports a mechanism of helicase activity involving initial recognition of the requisite 3' single-stranded region on the nucleic acid substrate by a conserved arginine-rich sequence on the RNA binding domain. Comparison of crystallographically independent molecules shows that rotation of the RNA binding domain involves conformational changes within a conserved TATPP sequence and untwisting of an extended antiparallel beta-sheet. Location of the TATPP sequence at the end of an NTPase domain beta-strand structurally homologous to the 'switch region' of many NTP-dependent enzymes offers the possibility that domain rotation is coupled to NTP hydrolysis in the helicase catalytic cycle.
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Affiliation(s)
- N Yao
- Structural Chemistry and Virology Department, Schering-Plough Research Institute, Kensworth, New Jersey 07033, USA
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13
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Alexander DM, Hesson T, Mannarino A, Cable M, Dalie BL. Isolation and purification of a biologically active human platelet-derived growth factor BB expressed in Escherichia coli. Protein Expr Purif 1992; 3:204-11. [PMID: 1392617 DOI: 10.1016/1046-5928(92)90016-p] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Human platelet-derived growth factor (PDGF) was expressed in Escherichia coli from a high-level cytoplasmic expression vector. A cDNA fragment encoding the mature form of the human PDGF B chain (hPDGF-B) was cloned into a plasmid under transcriptional control of the inducible E. coli Tac promoter. Expression of hPDGF-B from the final construct, pTacBIq, is regulated by the lactose repressor (LacIq). Upon induction, a polypeptide of approximately 14 kDa that had the same molecular mass and immunoreactivity as authentic hPDGF-B was produced. The production of recombinant hPDGF-B was significantly increased in an E. coli strain (CAG629) defective in expression of the lon protease. Expression of hPDGF-B in the CAG629 strain accounted for approximately 1% of total cell protein. In this system, hPDGF-B is expressed as an insoluble, intracellular protein and can readily be obtained in a partially purified form after differential centrifugation. Amino acid sequence determination of the purified protein has verified that the amino-terminal portion of the recombinant PDGF is correct. After renaturation into dimers, the purified recombinant hPDGF is fully functional in assays for receptor binding and mitogenesis.
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Affiliation(s)
- D M Alexander
- Department of Biotechnology/Molecular Biology, Schering-Plough Research, Bloomfield, New Jersey 07003
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14
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Abstract
Antibody raised to a synthetic dodecapeptide, corresponding to the C-terminal portion of the human renin pro-segment, was tested for its ability to recognize highly purified human inactive or active (mature) renins; immune complexes were detected by precipitation with protein A-Sepharose. Serial antibody dilutions caused identical binding of renal or plasma inactive renins but failed to bind active renin. In contrast, antibody to active renin recognized both active and inactive forms. Reversible acid activation of inactive renin enhanced its binding to the anti-prorenin antibody, whereas irreversible trypsin activation significantly reduced binding. Binding was abolished following prolonged exposure to trypsin or if inactive renin was acidified prior to trypsin treatment. These results indicate that inactive renin shares immunochemical determinants with prorenin; they suggest that acidification alters the conformation of the pro-segment and that trypsin can convert the molecule both to fully mature renin and to intermediate form(s).
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