I04-1-Macromolecular Crystallography (fixed wavelength)
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Lucía
Serran Aguilera
,
Elena
Mariotto
,
Gianluca
Rubbini
,
Francisco Fermín
Castro Navas
,
Carmen
Marco
,
María Paz
Carrasco-jiménez
,
Marco
Ballarotto
,
Antonio
Macchiarulo
,
Ramon
Hurtado-guerrero
,
Giampietro
Viola
,
Luisa Carlota
Lopez-cara
Diamond Proposal Number(s):
[8035]
Abstract: Seeking for new anticancer drugs with strong antiproliferative activity and simple molecular structure, we designed a novel series of compounds based on our previous reported pharmacophore model composed of five moieties. Antiproliferative assays on four tumoral cell lines and evaluation of Human Choline Kinase CKα1 enzymatic activity was performed for these compounds. Among tested molecules, those ones with biphenyl spacer showed betters enzymatic and antiproliferative activities (n-v). Docking and crystallization studies validate the hypothesis and confirm the results. The most active compound (t) induces a significant arrest of the cell cycle in G0/G1 phase that ultimately lead to apoptosis, following the mitochondrial pathway, as demonstrated for other choline kinase inhibitors. However additional assays reveal that the inhibition of choline uptake could also be involved in the antiproliferative outcome of this class of compounds.
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Dec 2020
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I02-Macromolecular Crystallography
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Alfredo
Picado
,
Apirat
Chaikuad
,
Carrow I.
Wells
,
Safal
Shrestha
,
William J.
Zuercher
,
Julie E.
Pickett
,
Frank E.
Kwarcinski
,
Parvathi
Sinha
,
Chandi S.
De Silva
,
Reena
Zutshi
,
Shubin
Liu
,
Natarajan
Kannan
,
Stefan
Knapp
,
David H.
Drewry
,
Timothy M.
Willson
Abstract: STK17B is a member of the death-associated protein kinase family and has been genetically linked to the development of diverse diseases. However, the role of STK17B in normal and disease pathology is poorly defined. Here, we present the discovery of thieno[3,2-d] pyrimidine SGC-STK17B-1 (11s), a high-quality chemical probe for this understudied “dark” kinase. 11s is an ATP-competitive inhibitor that showed remarkable selectivity over other kinases including the closely related STK17A. X-ray crystallography of 11s and related thieno[3,2-d]pyrimidines bound to STK17B revealed a unique P-loop conformation characterized by a salt bridge between R41 and the carboxylic acid of the inhibitor. Molecular dynamic simulations of STK17B revealed the flexibility of the P-loop and a wide range of R41 conformations available to the apo-protein. The isomeric thieno[2,3-d]pyrimidine SGC-STK17B-1N (19g) was identified as a negative control compound. The >100-fold lower activity of 19g on STK17B was attributed to the reduced basicity of its pyrimidine N1.
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Nov 2020
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I02-Macromolecular Crystallography
I04-Macromolecular Crystallography
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Yousuke
Yamada
,
Hajime
Takashima
,
David Lee
Walmsley
,
Fumihito
Ushiyama
,
Yohei
Matsuda
,
Harumi
Kanazawa
,
Toru
Yamaguchi-sasaki
,
Nozomi
Tanaka-yamamoto
,
Junya
Yamagishi
,
Risa
Kurimoto-tsuruta
,
Yuya
Ogata
,
Norikazu
Ohtake
,
Hayley
Angove
,
Lisa
Baker
,
Richard
Harris
,
Alba
Macias
,
Alan
Robertson
,
Allan
Surgenor
,
Hayato
Watanabe
,
Koichiro
Nakano
,
Masashi
Mima
,
Kunihiko
Iwamoto
,
Atsushi
Okada
,
Iichiro
Takata
,
Kosuke
Hitaka
,
Akihiro
Tanaka
,
Kiyoko
Fujita
,
Hiroyuki
Sugiyama
,
Roderick E.
Hubbard
Diamond Proposal Number(s):
[12428]
Abstract: UDP-3-O-acyl-N-acetylglucosamine deacetylase (LpxC) is a zinc metalloenzyme that catalyzes the first committed step in the biosynthesis of Lipid A, an essential component of the cell envelope of Gram-negative bacteria. The most advanced, disclosed LpxC inhibitors showing antibacterial activity coordinate zinc through a hydroxamate moiety with concerns about binding to other metalloenzymes. Here, we describe the discovery, optimization, and efficacy of two series of compounds derived from fragments with differing modes of zinc chelation. A series was evolved from a fragment where a glycine moiety complexes zinc, which achieved low nanomolar potency in an enzyme functional assay but poor antibacterial activity on cell cultures. A second series was based on a fragment that chelated zinc through an imidazole moiety. Structure-guided design led to a 2-(1S-hydroxyethyl)-imidazole derivative exhibiting low nanomolar inhibition of LpxC and a minimum inhibitory concentration (MIC) of 4 μg/mL against Pseudomonas aeruginosa, which is little affected by the presence of albumin.
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Nov 2020
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I02-Macromolecular Crystallography
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Zoltan
Szlavik
,
Marton
Csekei
,
Attila
Paczal
,
Zoltan B.
Szabo
,
Szabolcs
Sipos
,
Gabor
Radics
,
Agnes
Proszenyak
,
Balazs
Balint
,
James
Murray
,
James
Davidson
,
Ijen
Chen
,
Pawel
Dokurno
,
Allan E
Surgenor
,
Zoe Marie
Daniels
,
Roderick E.
Hubbard
,
Gaëtane
Le Toumelin-braizat
,
Audrey
Claperon
,
Gaëlle
Lysiak-auvity
,
Anne-marie
Girard
,
Alain
Bruno
,
Maia
Chanrion
,
Frédéric
Colland
,
Ana-leticia
Maragno
,
Didier
Demarles
,
Olivier
Geneste
,
Andras
Kotschy
Diamond Proposal Number(s):
[2103]
Abstract: Myeloid cell leukemia 1 (Mcl-1) has emerged as an attractive target for cancer therapy. It is an antiapoptotic member of the Bcl-2 family of proteins, whose upregulation in human cancers is associated with high tumor grade, poor survival, and resistance to chemotherapy. Here we report the discovery of our clinical candidate S64315, a selective small molecule inhibitor of Mcl-1. Starting from a fragment derived lead compound, we have conducted structure guided optimization that has led to a significant (3 log) improvement of target affinity as well as cellular potency. The presence of hindered rotation along a biaryl axis has conferred high selectivity to the compounds against other members of the Bcl-2 family. During optimization, we have also established predictive PD markers of Mcl-1 inhibition and achieved both efficient in vitro cell killing and tumor regression in Mcl-1 dependent cancer models. The preclinical candidate has drug-like properties that have enabled its development and entry into clinical trials.
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Nov 2020
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I02-Macromolecular Crystallography
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Gary
Tresadern
,
Ingrid
Velter
,
Andrés A.
Trabanco
,
Frans
Van Den Keybus
,
Gregor J.
Macdonald
,
Marijke V. F.
Somers
,
Greet
Vanhoof
,
Philip M.
Leonard
,
Marieke B. A. C.
Lamers
,
Yves E. M.
Van Roosbroeck
,
Peter J. J. A.
Buijnsters
Diamond Proposal Number(s):
[5603]
Abstract: We describe the hit-to-lead exploration of a [1,2,4]triazolo[1,5-a]pyrimidine phosphodiesterase 2A (PDE2A) inhibitor arising from high-throughput screening. X-ray crystallography enabled structure-guided design, leading to the identification of preferred substructural components. Further rounds of optimization used relative binding free-energy calculations to prioritize different substituents from the large accessible chemical space. The free-energy perturbation (FEP) calculations were performed for 265 putative PDE2A inhibitors, and 100 compounds were synthesized representing a relatively large prospective application providing unexpectedly active molecules with IC50′s from 2340 to 0.89 nM. Lead compound 46 originating from the FEP calculations showed PDE2A inhibition IC50 of 1.3 ± 0.39 nM, ∼100-fold selectivity versus other PDE enzymes, clean cytochrome P450 profile, in vivo target occupancy, and promise for further lead optimization.
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Oct 2020
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I04-1-Macromolecular Crystallography (fixed wavelength)
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William
Mahy
,
Nicky J.
Willis
,
Yuguang
Zhao
,
Hannah L.
Woodward
,
Fredrik
Svensson
,
James
Sipthorp
,
Luca
Vecchia
,
Reinis R.
Ruza
,
James
Hillier
,
Svend
Kjær
,
Sarah
Frew
,
Amy
Monaghan
,
Magda
Bictash
,
Patricia C.
Salinas
,
Paul
Whiting
,
Jean-paul
Vincent
,
E. Yvonne
Jones
,
Paul V.
Fish
Diamond Proposal Number(s):
[16814]
Abstract: Carboxylesterase Notum is a negative regulator of the Wnt signaling pathway. There is an emerging understanding of the role Notum plays in disease, supporting the need to discover new small-molecule inhibitors. A crystallographic X-ray fragment screen was performed, which identified fragment hit 1,2,3-triazole 7 as an attractive starting point for a structure-based drug design hit-to-lead program. Optimization of 7 identified oxadiazol-2-one 23dd as a preferred example with properties consistent with drug-like chemical space. Screening 23dd in a cell-based TCF/LEF reporter gene assay restored the activation of Wnt signaling in the presence of Notum. Mouse pharmacokinetic studies with oral administration of 23dd demonstrated good plasma exposure and partial blood–brain barrier penetration. Significant progress was made in developing fragment hit 7 into lead 23dd (>600-fold increase in activity), making it suitable as a new chemical tool for exploring the role of Notum-mediated regulation of Wnt signaling.
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Oct 2020
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I04-1-Macromolecular Crystallography (fixed wavelength)
I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Diamond Proposal Number(s):
[9537, 14043, 18548]
Abstract: CK2α is a ubiquitous, well-studied kinase that is a target for small-molecule inhibition, for treatment of cancers. While many different classes of adenosine 5′-triphosphate (ATP)-competitive inhibitors have been described for CK2α, they tend to suffer from significant off-target activity and new approaches are needed. A series of inhibitors of CK2α has recently been described as allosteric, acting at a previously unidentified binding site. Given the similarity of these inhibitors to known ATP-competitive inhibitors, we have investigated them further. In our thorough structural and biophysical analyses, we have found no evidence that these inhibitors bind to the proposed allosteric site. Rather, we report crystal structures, competitive isothermal titration calorimetry (ITC) and NMR, hydrogen–deuterium exchange (HDX) mass spectrometry, and chemoinformatic analyses that all point to these compounds binding in the ATP pocket. Comparisons of our results and experimental approach with the data presented in the original report suggest that the primary reason for the disparity is nonspecific inhibition by aggregation.
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Oct 2020
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I04-Macromolecular Crystallography
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Sonia
Martínez-gonzález
,
Ana
Belén García
,
M. Isabel
Albarrán
,
Antonio
Cebriá
,
Adrián
Amezquita-alves
,
Francisco Javier
García-campos
,
Jaime
Martínez-gago
,
Jorge
Martínez-torrecuadrada
,
Ines
Munoz
,
Carmen
Blanco-aparicio
,
Joaquín
Pastor
Diamond Proposal Number(s):
[16252]
Abstract: CDK8 is a cyclin-dependent kinase that forms part of the mediator complex, and modulates the transcriptional output from distinct transcription factors involved in oncogenic control. Overexpression of CDK8 has been observed in various cancers, representing a potential target for developing novel CDK8 inhibitors in cancer therapeutics. In the course of our investigations to discover new CDK8 inhibitors, we designed and synthesized tricyclic pyrido[2,3-b][1,5]benzoxazepin-5(6H)-one derivatives, by introduction of chemical complexity in the multi-kinase inhibitor Sorafenib taking into account the flexibility of the P-loop motif of CDK8 protein observed after analysis of structural information of co-crystallized CDK8 inhibitors. In vitro evaluation of the inhibitory activity of the prepared compounds against CDK8 led us to identify compound 2 as the most potent inhibitor of the series (IC50 = 8.25 nM). Co-crystal studies and the remarkable selectivity profile of compound 2 are presented. Compound 2 showed moderate reduction of phosphorylation of CDK8 substrate STAT1 in cells, in line with other reported Type II CDK8 inhibitors. We propose herein an alternative to find a potential therapeutic use for this chemical series.
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Sep 2020
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I04-Macromolecular Crystallography
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Xiaohui
Du
,
Jared
Moore
,
Brian R.
Blank
,
John
Eksterowicz
,
Dena
Sutimantanapi
,
Natalie
Yuen
,
Todd
Metzger
,
Brenda
Chan
,
Tom
Huang
,
Xi
Chen
,
Yuping
Chen
,
Frank
Duong
,
Wayne
Kong
,
Jae H.
Chang
,
Jessica
Sun
,
Tatiana
Zavorotinskaya
,
Qiuping
Ye
,
Melissa R.
Junttila
,
Chudi
Ndubaku
,
Lori S.
Friedman
,
Valeria R.
Fantin
,
Daqing
Sun
Abstract: The adenosinergic pathway represents an attractive new therapeutic approach in cancer immunotherapy. In this pathway, ecto-5-nucleotidase CD73 has the unique function of regulating production of immunosuppressive adenosine (ADO) through the hydrolysis of AMP. CD73 is overexpressed in many cancers, resulting in elevated levels of ADO that correspond to poor patient prognosis. Therefore, reducing the level of ADO via inhibition of CD73 is a potential strategy for treating cancers. Based on the binding mode of adenosine 5′-(α,β-methylene)diphosphate (AOPCP) with human CD73, we designed a series of novel monophosphonate small-molecule CD73 inhibitors. Among them, OP-5244 (35) proved to be a highly potent and orally bioavailable CD73 inhibitor. In preclinical studies, 35 completely inhibited ADO production in both human cancer cells and CD8+ T cells. Furthermore, 35 lowered the ratio of ADO/AMP significantly and reversed immunosuppression in mouse models, indicating its potential as an in vivo tool compound for further development.
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Sep 2020
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I02-Macromolecular Crystallography
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Diamond Proposal Number(s):
[442]
Abstract: Selectivity remains a challenge for ATP-mimetic kinase inhibitors, an issue that may be overcome by targeting unique residues or binding pockets. However, to date only few strategies have been developed. Here we identify that bulky residues located N-terminal to the DFG motif (DFG-1) represent an opportunity for designing highly selective inhibitors with unexpected binding modes. We demonstrate that several diverse inhibitors exerted selective, non-canonical binding modes that exclusively target large hydrophobic DFG-1 residues present in many kinases including PIM, CK1, DAPK and CLK. Using the CLK family as a model, structural and biochemical data revealed that the DFG-1 valine controlled a non-canonical binding mode in CLK1, providing a rational for selectivity over the closely-related CLK3 which harbors a smaller DFG-1 alanine. Our data suggests that targeting the restricted back pocket in the small fraction of kinases that harbor bulky DFG-1 residues offers a versatile selectivity filter for inhibitor design.
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Aug 2020
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