I03-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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María
Conde-Giménez
,
Sandra
Salillas
,
María
Galiana-Cameo
,
Juan E.
Martínez-Oliván
,
Alejandro
Mahía
,
Manuel
Ledesma
,
Juan José
Galano-Frutos
,
Ritwik
Maity
,
Adrián
Velázquez-Campoy
,
María D.
Díaz-De-Villegas
,
Ramon
Hurtado-Guerrero
,
Javier
Sancho
Diamond Proposal Number(s):
[14739]
Open Access
Abstract: henylketonuria (PKU) is an inherited metabolic disorder caused by pathogenic variants in phenylalanine hydroxylase (PAH), leading to toxic phenylalanine accumulation and severe neurological complications if untreated. Current pharmacological treatment relies on tetrahydrobiopterin (BH4), which benefits only a subset of patients, highlighting a major unmet need for alternative therapies. Here, we combined high-throughput screening, computational modelling, and drug repurposing to identify pharmacological chaperones capable of rescuing PAH function. We evaluated 26 structurally diverse small molecules in HEK293T cells expressing wild-type PAH or one of eight PKU-associated variants spanning phenotypes from mild to classical disease. Chaperoning efficacy was strongly variant-dependent, and for every variant tested at least one compound produced a greater activity increase than BH4 under identical assay conditions. Notably, belinostat, a clinically approved histone deacetylase inhibitor, emerged as the most effective compound for several clinically severe variants. Mechanistically, functional rescue consistently correlated with an increased population of tetrameric, catalytically competent PAH, as quantified by mass photometry. The crystal structure of the PAH–belinostat complex (PDB ID: 9T1O), together with structural models for all compounds, provide a framework for rational optimization. These results establish a preclinical proof-of-concept for genotype-guided pharmacological chaperone therapy in PKU and support the feasibility of personalized, variant-specific treatment strategies.
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Jun 2026
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Holger
Greschik
,
Florian
Friedrich
,
Ludwig
Seifert
,
Farnoush
Mousavizadeh
,
Francesco
Fiorentino
,
Johannes
Walz
,
Lin
Zhang
,
Jianyu
Li
,
Emanuele
Fabbrizi
,
Stefano
Tomassi
,
Farhad
Panahi
,
Niklas
Papenkordt
,
Silas L.
Wurnig
,
Johannes
Osterroth
,
Anna M.
Strasser
,
Jan
Ruprecht
,
Aurélien F. A.
Moumbock
,
Martin
Hügle
,
Manuela
Sum
,
Ling
Peng
,
Sheng
Wang
,
Adina A.
Baniahmad
,
Laura
Pulido-Cortés
,
H. Th. Marc
Timmers
,
Ralf
Flaig
,
Eric
Metzger
,
Bernhard
Breit
,
Oliver
Einsle
,
Stefan
Günther
,
Dante
Rotili
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Antonello
Mai
,
Roland
Schüle
,
Manfred
Jung
Open Access
Abstract: The chromatin remodeler CHD1, a regulator of gene activity and potential drug target in prostate cancer (PCa), contains a tandem chromodomain (tCD) binding histone H3 trimethylated at lysine 4 (H3K4me3). We developed the first submicromolar inhibitors (2n and 2s) that target the H3K4me3 binding site of the CHD1 tCD with Kd values of 0.15 μM and 0.14 μM, respectively. Co-crystal structures of these quinoline-based compounds revealed aromatic cage interactions and extended ligand contacts in other parts of the H3K4me3 peptide pocket as the main determinants of high-affinity ligand binding. 2n and 2s engage endogenous CHD1 in cell lysates or the exogenous CHD1 tCD in cells. Furthermore, we provide evidence for selectivity against a panel of methyl-lysine readers and epigenetic enzymes as well as impairment of PCa cell viability. Due to their high potency and defined binding mode, our ligands offer new directions for further optimization.
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May 2026
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I03-Macromolecular Crystallography
I04-1-Macromolecular Crystallography (fixed wavelength)
I04-Macromolecular Crystallography
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Diamond Proposal Number(s):
[14043, 25402, 33658, 40158]
Open Access
Abstract: Bruton’s Tyrosine Kinase (BTK) is a validated target for hematological malignancies, with numerous FDA-approved inhibitors on the market. Current therapies target the highly conserved ATP binding site and hence limit the therapeutic index given the site’s highly conserved nature across the kinome. We explore a novel approach for BTK inhibition by targeting the PH domain-mediated membrane recruitment and activation of BTK. We have identified a fragment which covalently modifies a lysine in the inositol phosphate (PIP3) binding site and inhibits the binding of a soluble PIP3 headgroup analog to the PH domain. Fragment growth and an extensive structure-binding relationship study uncovered 27 crystal structures and a best-in-class analog, 24. Evaluation of pKa values of the targeted lysine in BTK and other PH domains suggests this as a more general approach to PH domain inhibition.
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May 2026
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I04-Macromolecular Crystallography
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Philipp
Münick
,
Dimitrios-Ilias
Balourdas
,
Julianne S.
Funk
,
Büşra
Yüksel
,
Danai
Mavridi
,
Justin
Heftel
,
Birgit
Dreier
,
Jonas V.
Schaefer
,
Birgit
Schäfer
,
Stefan
Knapp
,
Tümay
Telatar
,
Baki
Akgül
,
Andreas
Plückthun
,
Thorsten
Stiewe
,
Andreas C.
Joerger
,
Volker
Dötsch
Abstract: The tumor suppressor p53 is the most frequently mutated protein in tumors and a target for drug development. More than 2000 cancer-associated p53 missense mutations have been reported, most of them located in the DNA-binding domain (DBD). Due to the low intrinsic thermostability of the latter, they often lead to unfolding at physiological temperature. Stabilizing the DBD with small molecules has been shown to be effective in reactivating the cavity-creating cancer mutant Y220C. Unfortunately, the majority of p53 mutants seem to lack druggable binding pockets for small molecules. Here we show that a designed ankyrin repeat protein (DARPin) that binds to the p53 DBD stabilizes temperature-sensitive (TS) p53 cancer mutants, thereby compensating for mutation-induced loss of stability. We determined high-resolution crystal structures of multiple DARPin–mutant p53 complexes, providing mechanistic insights into this mode of stabilization. Reporter gene assays across a comprehensive panel of cancer-associated mutants revealed reactivation of the majority of TS mutants, whereas DNA-contact mutants and those with local misfolding of the DNA-binding surface remained inactive, as expected. We demonstrate that this reactivation induces the transcription of canonical p53 target genes and elicits antiproliferative effects in cancer cell lines. A combination of this DARPin with an mRNA/lipid nanoparticle-based transfection approach may have the potential to reactivate most TS p53 mutants and resensitize cancer cells to chemotherapy.
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May 2026
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I03-Macromolecular Crystallography
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Monisha
Singha
,
Liam A.
Wilson
,
Elisabete C.
C. M. Moura
,
Maria M.
Trush
,
Karina
Calvopina
,
Gurleen
Kaur
,
Greta
Zaborskytė
,
Toms
Kalniņš
,
Tharindi
Panduwawala
,
Matthew J.
Bowen
,
Matthew J.
Beech
,
Jurgen
Brem
,
Peter J.
Mchugh
,
Edgars
Suna
,
Timothy R.
Walsh
,
Christopher J.
Schofield
,
Alistair J. M.
Farley
Diamond Proposal Number(s):
[31353]
Open Access
Abstract: Use of the clinically vital β-lactam antibiotics is increasingly compromised by resistance, commonly mediated by β-lactamases. While clinically used serine-β-lactamase (SBL) inhibitors have long been available, metallo-β-lactamase (MBL) inhibitors are not yet approved for clinical use. We report the structure-guided development of pyrrole-2-carboxylic acid derivatives as potent inhibitors of the clinically important di-Zn(II) ion containing B1 MBLs (NDM-1, VIM-1, VIM-2, IMP-1). Crystallographic studies reveal the pyrrole-2-carboxylic acids inhibit B1 MBLs via active site Zn(II)-coordination of the inhibitor carboxylate and trapping of the di-Zn(II) ion bridging hydroxide, the latter of which reacts with the substrate β-lactam ring during hydrolysis. Appropriately derivatized pyrrole-2-carboxylic acids enhance the activity of carbapenems against MBL producing Gram-negative clinical isolates. The results support further development of metalloenzyme inhibitors that exploit binding to structural or catalytically important water molecules, an approach which may help in achieving selectivity over other metalloenzymes compared to metal-chelation based approaches.
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May 2026
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I03-Macromolecular Crystallography
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Michael J.
Lambrecht
,
Jun
Liang
,
Peter Man-Un
Ung
,
Malcolm P.
Huestis
,
Bing-Yan
Zhu
,
Lisa M.
Barton
,
Georgette M.
Castanedo
,
Jason R.
Zbieg
,
Robin
Larouche-Gauthier
,
Araz
Jakalian
,
Jean-Philippe
Leclerc
,
Arun
Yadav
,
Pouyan
Haghshenas
,
Samuel
Aubert-Nicol
,
Hossein
Ismaili
,
Liang
Zhao
,
Mélissa
Leblanc
,
Jian
Wang
,
Shouliang
Wang
,
Qiuyue
Wang
,
Thomas
Garner
,
Sophia
Tan
,
Madeleine
Prangley
,
Fabio
Broccatelli
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Jodie
Pang
,
Jeremy
Murray
,
Christine
Yu
,
Peter
Hsu
,
Sascha
Rutz
,
Satoko
Kakiuchi-Kiyota
,
Isabel
Ishizuka
,
Dennis H.
Leung
,
Ponien
Kou
,
Linda
Bao
,
Xiaojing
Wang
Abstract: Casitas B-lineage lymphoma-b (Cbl-b), an E3 ubiquitin ligase, is a key negative regulator of immune function, and its inhibition is a promising strategy for cancer immunotherapy. Here, we show the optimization of a series of inactive-state Cbl-b inhibitors to improve their potency and pharmacokinetic properties. Through systematic modification of a benzylic amine and a linker region, compound 16 was identified, which demonstrates a favorable balance of biochemical potency, cellular activity, and in vitro ADME properties. Despite exhibiting high IV clearance in vivo, compound 16 achieved oral exposures sufficient to demonstrate significant tumor growth inhibition in a murine CT26 colon-cancer model.
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May 2026
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I04-1-Macromolecular Crystallography (fixed wavelength)
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Michael
Berlin
,
Jennifer
Cantley
,
Fabio
Broccatelli
,
Lin
Cao
,
Huifen
Chen
,
Tommy K.
Cheung
,
Andrew P.
Crew
,
Dean
Dinicola
,
Hanqing
Dong
,
Matthew
Grimmer
,
Brian D.
Hamman
,
Alicia
Harbin
,
Mingtao
He
,
Xiuxian
Hu
,
Alison J.
Hole
,
Thomas
Januario
,
Philip S.
Kerry
,
Xiangjia
Liu
,
Connor
Quinn
,
Christopher M.
Rose
,
Emma
Rousseau
,
Lawrence B.
Snyder
,
Leanna R.
Staben
,
Gan
Wang
,
Jing
Wang
,
Xiaofen
Ye
,
Robert L.
Yauch
,
Peter S.
Dragovich
Diamond Proposal Number(s):
[23279]
Open Access
Abstract: Modification of the VHL-binding fragments contained in proteolysis targeting chimeras (PROTACs) that potently degrade the BRM protein (also known as SMARCA2) improved degradation selectivity over the closely-related paralog protein BRG1 (SMARCA4). In particular, replacement of the phenyl-thiazole entity commonly employed in the generation of VHL-dependent PROTACs with pyridyl-thiazole, phenyl imidazole, and phenyl-nitrile moieties consistently improved the BRG1/BRM degradation selectivity ratios of multiple, structurally-diverse degrader compounds. Crystal structures of these new VHL-binding fragments in complex with the VHL protein were obtained to better understand their interactions. Some of these VHL alterations, the phenyl-nitrile substitution in particular, afforded molecules that displayed strong antiproliferative activities against BRM-dependent (BRG1-mutant) cancers but minimal potency toward wild-type cell lines. One such compound (21, G-9293) was profiled in detailed broad proteomics and chromatin accessibility experiments, and its biological properties were clearly differentiated from a less-selective BRM-degrader (5, A947) in the latter assessment. The highly selective molecule (21, G-9293) was also extensively profiled in vitro using a panel of lung cancer cell lines (defined by BRG1 or BRM status) along with several prostate cancer lines. It exhibited similar antiproliferation activity relative to the less-selective BRM-degrader (5, A947) against the lung lines but significantly diminished potency toward the prostate cancer cells.
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May 2026
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Krios II-Titan Krios II at Diamond
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Valentina A.
Spiteri
,
Dmitri
Segal
,
Alejandro
Correa-Sáez
,
Kentaro
Iso
,
Ryan
Casement
,
Miquel
Muñoz I Ordoño
,
Mark A.
Nakasone
,
Gajanan
Sathe
,
Caroline
Schätz
,
Hannah E.
Peters
,
Mark
Doward
,
Lisa
Kainacher
,
Angus D.
Cowan
,
Alessio
Ciulli
,
Georg E.
Winter
Diamond Proposal Number(s):
[37630]
Open Access
Abstract: Proteolysis-targeting chimeras (PROTACs) and molecular glue degraders (MGDs) target proteins for degradation by co-opting an E3 ligase. While heterotrivalent PROTACs that can recruit multiple E3 ligases have been described, all MGDs reported to date depend on a single E3. Using orthogonal genetic screening, biophysical and structural analyses, we show that a monovalent MGD can recruit CUL4DCAF16 and CRL1FBXO22 in parallel to degrade SMARCA2/4. Deep mutational scanning identifies C173 in DCAF16 as essential for degrader activity and intact protein mass spectrometry confirms covalent modification at this site. Elucidating the ternary complex structure reveals a unique binding mode and a distinct interface of neointeractions that underlie degrader specificity. We demonstrate that ligase dependency is chemically and genetically tunable. Minimal compound modifications shift preference from DCAF16 to FBXO22, while a single substitution boosts degrader dependency on DCAF16. These results establish a framework for designing tunable dual E3 ligase degraders to mitigate potential resistance mechanisms.
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May 2026
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I13-2-Diamond Manchester Imaging
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Karo
De Rycke
,
Marina
Horvat
,
Lisa
Caboor
,
Petra
Vermassen
,
Griet
De Smet
,
Sophie
Lobbestael
,
Marta
Santana Silva
,
Wouter
Steyaert
,
Matthias
Van Impe
,
Patrick
Segers
,
Julie
De Backer
,
Patrick
Sips
Diamond Proposal Number(s):
[32919]
Open Access
Abstract: Fibrillin defects lead to severe cardiovascular complications in Marfan syndrome (MFS), including aortic dilation, dissection, and rupture. To model MFS, zebrafish mutants lacking various fibrillin genes were generated. Among these mutant lines, only fibrillin-3–deficient zebrafish exhibited cardiovascular phenotypes mimicking human disease. Multimodal imaging revealed early cardiac defects, bulbus arteriosus dilation, and valve abnormalities. Transcriptomic analysis identified altered regulation of pathways related to extracellular matrix homeostasis and immune system activation. This zebrafish model, recapitulating key cardiovascular features of MFS, provides a valuable platform to investigate disease mechanisms and identify novel treatment strategies.
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May 2026
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I03-Macromolecular Crystallography
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Sarah
Hijazi
,
Francesco
Marchesani
,
Marialaura
Marchetti
,
Valeria
Buoli Comani
,
Paul
Brear
,
Barbara
Campanini
,
Luca
Ronda
,
Serena
Faggiano
,
Eleonora
Gianquinto
,
Somayeh
Asgharpour Hassankiade
,
Barbara
Rolando
,
Francesca
Spyrakis
,
Carlotta
Compari
,
Loretta
Lazzarato
,
Omar
De Bei
,
Emanuela
Frangipani
,
Stefano
Bettati
Diamond Proposal Number(s):
[25402]
Open Access
Abstract: Infections caused by Staphylococcus aureus depend on its ability to access essential nutrients, including acquiring iron from human hemoglobin (Hb) through the iron-regulated surface determinant (Isd) system. The compound 4-[(2-{[5-(1H-indol-3-yl)-1,3,4-oxadiazol-2-yl]sulfanyl}acetyl)amino]benzoic acid (C35) was recently identified as a promising antimicrobial agent for its ability to bind Hb and hamper its interaction with the staphylococcal hemophore IsdB in vitro. Here, we show that C35 inhibits S. aureus growth by targeting the hemophore-driven iron-acquisition system, highlighting its potential as an inhibitor and validating hemophores as antibacterial targets. Furthermore, for drug design purposes, we solved the X-ray structure of Hb:C35 complex. In contrast to the predicted binding pose, C35 binds tetrameric Hb in a cleft between the α subunits, stabilizing a relaxed conformation (R2) and increasing Hb oxygen affinity. This serendipitous result hints to C35 as a promising scaffold for developing compounds with diverse, or even dual, therapeutic aims, with antimicrobial and Hb-modulating activity.
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May 2026
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