I03-Macromolecular Crystallography
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Maria Giulia
Nizi
,
Mirko M.
Maksimainen
,
Sudarshan
Murthy
,
Serena
Massari
,
Juho
Alaviuhkola
,
Barbara E.
Lippok
,
Sven T.
Sowa
,
Albert
Galera-Prat
,
Renata
Prunskaite-Hyyryläinen
,
Bernhard
Lüscher
,
Patricia
Korn
,
Lari
Lehtio
,
Oriana
Tabarrini
Diamond Proposal Number(s):
[19951]
Abstract: While human poly-ADP-ribose chain generating poly-ARTs, PARP1 and 2 and TNKS1 and 2, have been widely characterized, less is known on the pathophysiological roles of the mono-ADP-ribosylating mono-ARTs, partly due to the lack of selective inhibitors. In this context, we have focused on the development of inhibitors for the mono-ART PARP10, whose overexpression is known to induce cell death. Starting from OUL35 (1) and its 4-(benzyloxy)benzamidic derivative (2) we herein report the design and synthesis of new analogues from which the cyclobutyl derivative 3c rescued cells most efficiently from PARP10 induced apoptosis. Most importantly, we also identified 2,3-dihydrophthalazine-1,4-dione as a new suitable nicotinamide mimicking PARP10 inhibitor scaffold. When it was functionalized with cycloalkyl (8a-c), o-fluorophenyl (8h), and thiophene (8l) rings, IC50 values in the 130–160 nM range were obtained, making them the most potent PARP10 inhibitors reported to date. These compounds also inhibited PARP15 with low micromolar IC50s, but none of the other tested poly- and mono-ARTs, thus emerging as dual mono-ART inhibitors. Compounds 8a, 8h and 8l were also able to enter cells and rescue cells from apoptosis. Our work sheds more light on inhibitor development against mono-ARTs and identifies chemical probes to study the cellular roles of PARP10 and PARP15.
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Jul 2022
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I03-Macromolecular Crystallography
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Diamond Proposal Number(s):
[19951]
Open Access
Abstract: Tankyrases are ADP-ribosylating enzymes that regulate many physiological processes in the cell and are considered promising drug targets for cancer and fibrotic diseases. The catalytic ADP-ribosyltransferase domain of tankyrases contains a unique zinc-binding motif of unknown function. Recently, this motif was suggested to be involved in the catalytic activity of tankyrases. In this work, we set out to study the effect of the zinc-binding motif on the activity, stability and structure of human tankyrases. We generated mutants of human tankyrase (TNKS) 1 and TNKS2, abolishing the zinc-binding capabilities, and characterized the proteins biochemically and biophysically in vitro. We further generated a crystal structure of TNKS2, in which the zinc ion was oxidatively removed. Our work shows that the zinc-binding motif in tankyrases is a crucial structural element which is particularly important for the structural integrity of the acceptor site. While mutation of the motif rendered TNKS1 inactive, probably due to introduction of major structural defects, the TNKS2 mutant remained active and displayed an altered activity profile compared to the wild-type.
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Mar 2022
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B21-High Throughput SAXS
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Diamond Proposal Number(s):
[19951, 21035]
Open Access
Abstract: Ubiquitination and ADP-ribosylation are post-translational modifications that play major roles in pathways including the DNA damage response and viral infection. The enzymes responsible for these modifications are therefore potential targets for therapeutic intervention. DTX3L is an E3 Ubiquitin ligase that forms a heterodimer with PARP9. In addition to its ubiquitin ligase activity, DTX3L-PARP9 also acts as an ADP-ribosyl transferase for Gly76 on the C-terminus of ubiquitin. NAD+-dependent ADP-ribosylation of ubiquitin by DTX3L-PARP9 prevents ubiquitin from conjugating to protein substrates. To gain insight into how DTX3L-PARP9 generates these post-translational modifications, we have generated recombinant forms of DTX3L and PARP9 and studied their physical interactions. We show the DTX3L D3 domain (230-510) mediates the interaction with PARP9 with nanomolar affinity and an apparent 1:1 stoichiometry. We also show that DTX3L and PARP9 assemble into a higher molecular weight oligomer, and that this is mediated by the DTX3L N-terminal region (1-200). Lastly, we show that ADP-ribosylation of ubiquitin at Gly76 is reversible in vitro by several Macrodomain-type hydrolases. Our study provides a framework to understand how DTX3L-PARP9 mediates ADP-ribosylation and ubiquitination through both intra- and inter-subunit interactions.
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Jan 2022
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I03-Macromolecular Crystallography
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Diamond Proposal Number(s):
[19951]
Open Access
Abstract: The scaffold of TIQ-A, a previously known inhibitor of human poly-ADP-ribosyltransferase PARP1, was utilized to develop inhibitors against human mono-ADP-ribosyltransferases through structure-guided design and activity profiling. By supplementing the TIQ-A scaffold with small structural changes, based on a PARP10 inhibitor OUL35, selectivity changed from poly-ADP-ribosyltransferases towards mono-ADP-ribosyltransferases. Binding modes of analogs were experimentally verified by determining complex crystal structures with mono-ADP-ribosyltransferase PARP15 and with poly-ADP-ribosyltransferase TNKS2. The best analogs of the study achieved 10–20-fold selectivity towards mono-ADP-ribosyltransferases PARP10 and PARP15 while maintaining micromolar potencies. The work demonstrates a route to differentiate compound selectivity between mono- and poly-ribosyltransferases of the human ARTD family.
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Dec 2021
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I04-Macromolecular Crystallography
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Ruben G. G.
Leenders
,
Shoshy Alam
Brinch
,
Sven T.
Sowa
,
Enya
Amundsen-Isaksen
,
Albert
Galera-Prat
,
Sudarshan
Murthy
,
Sjoerd
Aertssen
,
Johannes N.
Smits
,
Piotr
Nieczypor
,
Eddy
Damen
,
Anita
Wegert
,
Marc
Nazaré
,
Lari
Lehtio
,
Jo
Waaler
,
Stefan
Krauss
Open Access
Abstract: Tankyrase 1 and 2 (TNKS1/2) catalyze post-translational modification by poly-ADP-ribosylation of a plethora of target proteins. In this function, TNKS1/2 also impact the WNT/β-catenin and Hippo signaling pathways that are involved in numerous human disease conditions including cancer. Targeting TNKS1/2 with small-molecule inhibitors shows promising potential to modulate the involved pathways, thereby potentiating disease intervention. Based on our 1,2,4-triazole-based lead compound 1 (OM-1700), further structure–activity relationship analyses of East-, South- and West-single-point alterations and hybrids identified compound 24 (OM-153). Compound 24 showed picomolar IC50 inhibition in a cellular (HEK293) WNT/β-catenin signaling reporter assay, no off-target liabilities, overall favorable absorption, distribution, metabolism, and excretion (ADME) properties, and an improved pharmacokinetic profile in mice. Moreover, treatment with compound 24 induced dose-dependent biomarker engagement and reduced cell growth in the colon cancer cell line COLO 320DM.
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Dec 2021
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I24-Microfocus Macromolecular Crystallography
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Diamond Proposal Number(s):
[19951]
Open Access
Abstract: Human PARP2/ARTD2 is an ADP-ribosyltransferase which, when activated by 5′-phosphorylated DNA ends, catalyses poly-ADP-ribosylation of itself, other proteins and DNA. In this study, a crystal structure of PARP2 in complex with an activating 5′-phosphorylated DNA shows that the WGR domain bridges the dsDNA gap and joins the DNA ends. This DNA binding results in major conformational changes, including reorganization of helical fragments, in the PARP2 regulatory domain. A comparison of PARP1 and PARP2 crystal structures reveals how binding to a DNA damage site leads to formation of a catalytically competent conformation. In this conformation, PARP2 is capable of binding substrate NAD+ and histone PARylation factor 1 that changes PARP2 residue specificity from glutamate to serine when initiating DNA repair processes. The structure also reveals how the conformational changes in the autoinhibitory regulatory domain would promote the flexibility needed by the enzyme to reach the target macromolecule for ADP-ribosylation.
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Jun 2021
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I04-Macromolecular Crystallography
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Patricia
Korn
,
Arno
Classen
,
Sudarshan
Murthy
,
Riccardo
Guareschi
,
Mirko M.
Maksimainen
,
Barbara E.
Lippok
,
Albert
Galera‐prat
,
Sven T.
Sowa
,
Catharina
Voigt
,
Giulia
Rossetti
,
Lari
Lehtio
,
Carsten
Bolm
,
Bernhard
Lüscher
Diamond Proposal Number(s):
[19951]
Open Access
Abstract: Intracellular ADP-ribosyltransferases catalyze mono- and poly-ADP-ribosylation and affect a broad range of biological processes. The mono-ADP-ribosyltransferase PARP10 is involved in signaling and DNA repair. Previous studies identified OUL35 as a selective, cell permeable inhibitor of PARP10. We have further explored the chemical space of OUL35 by synthesizing and investigating structurally related analogs. Key synthetic steps were metal-catalyzed cross-couplings and functional group modifications. We identified 4-(4-cyanophenoxy)benzamide and 3-(4-carbamoylphenoxy)benzamide as PARP10 inhibitors with distinct selectivities. Both compounds were cell permeable and interfered with PARP10 toxicity. Moreover, both revealed some inhibition of PARP2 but not PARP1, unlike clinically used PARP inhibitors, which typically inhibit both enzymes. Using crystallography and molecular modeling the binding of the compounds to different ADP-ribosyltransferases was explored regarding selectivity. Together, these studies define additional compounds that interfere with PARP10 function and thus expand our repertoire of inhibitors to further optimize selectivity and potency.
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Jun 2021
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Ed
Daniel
,
Mirko M.
Maksimainen
,
Neil
Smith
,
Ville
Ratas
,
Ekaterina
Biterova
,
Sudarshan N.
Murthy
,
M. Tanvir
Rahman
,
Tiila-Riikka
Kiema
,
Shruthi
Sridhar
,
Gabriele
Cordara
,
Subhadra
Dalwani
,
Rajaram
Venkatesan
,
Jaime
Prilusky
,
Orly
Dym
,
Lari
Lehtio
,
M. Kristian
Koski
,
Alun W.
Ashton
,
Joel L.
Sussman
,
Rikkert K.
Wierenga
Open Access
Abstract: The web-based IceBear software is a versatile tool to monitor the results of crystallization experiments and is designed to facilitate supervisor and student communications. It also records and tracks all relevant information from crystallization setup to PDB deposition in protein crystallography projects. Fully automated data collection is now possible at several synchrotrons, which means that the number of samples tested at the synchrotron is currently increasing rapidly. Therefore, the protein crystallography research communities at the University of Oulu, Weizmann Institute of Science and Diamond Light Source have joined forces to automate the uploading of sample metadata to the synchrotron. In IceBear, each crystal selected for data collection is given a unique sample name and a crystal page is generated. Subsequently, the metadata required for data collection are uploaded directly to the ISPyB synchrotron database by a shipment module, and for each sample a link to the relevant ISPyB page is stored. IceBear allows notes to be made for each sample during cryocooling treatment and during data collection, as well as in later steps of the structure determination. Protocols are also available to aid the recycling of pins, pucks and dewars when the dewar returns from the synchrotron. The IceBear database is organized around projects, and project members can easily access the crystallization and diffraction metadata for each sample, as well as any additional information that has been provided via the notes. The crystal page for each sample connects the crystallization, diffraction and structural information by providing links to the IceBear drop-viewer page and to the ISPyB data-collection page, as well as to the structure deposited in the Protein Data Bank.
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Feb 2021
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I24-Microfocus Macromolecular Crystallography
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Open Access
Abstract: The folding of disulfide bond containing proteins in the endoplasmic reticulum (ER) is a complex process that requires protein folding factors, some of which are protein-specific. The ER resident saposin-like protein pERp1 (MZB1, CNPY5) is crucial for the correct folding of IgA, IgM and integrins. pERp1 also plays a role in ER calcium homeostasis and plasma cell mobility. As an important factor for proper IgM maturation and hence immune function, pERp1 is upregulated in many auto-immune diseases. This makes it a potential therapeutic target. pERp1 belongs to the CNPY family of ER resident saposin-like proteins. To date, five of these proteins have been identified. All are implicated in protein folding and all contain a saposin-like domain. All previously structurally characterized saposins are involved in lipid binding. However, there are no reports of CNPY family members interacting with lipids, suggesting a novel function for the saposin fold. However, the molecular mechanisms of their function remain elusive. To date, no structure of any CNPY protein has been reported. Here, we present the high-resolution (1.4 Å) crystal structure of human pERp1 and confirm that it has a saposin-fold with unique structural elements not present in other saposin-fold structures. The implications for the role of CNPY proteins in protein folding in the ER are discussed.
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Jan 2021
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I04-1-Macromolecular Crystallography (fixed wavelength)
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Diamond Proposal Number(s):
[19951]
Abstract: MacroD2 is one of the three human macrodomain proteins characterized by their protein-linked mono-ADP-ribosyl-hydrolyzing activity. MacroD2 is a single-domain protein that contains a deep ADP-ribose-binding groove. In this study, new crystallization conditions for MacroD2 were found and three crystal structures of human MacroD2 in the apo state were solved in space groups P41212, P43212 and P43, and refined at 1.75, 1.90 and 1.70 Å resolution, respectively. Structural comparison of the apo crystal structures with the previously reported crystal structure of MacroD2 in complex with ADP-ribose revealed conformational changes in the side chains of Val101, Ile189 and Phe224 induced by the binding of ADP-ribose in the active site. These conformational variations may potentially facilitate design efforts of a MacroD2 inhibitor.
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Oct 2020
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