I04-Macromolecular Crystallography
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Qin
Su
,
Max
Louwerse
,
Rob F.
Lammers
,
Elmer
Maurits
,
Max
Janssen
,
Rolf G.
Boot
,
Valentina
Borlandelli
,
Wendy A.
Offen
,
Daniël
Linzel
,
Sybrin P.
Schröder
,
Gideon J.
Davies
,
Herman S.
Overkleeft
,
Marta
Artola
,
Johannes M. F. G.
Aerts
Open Access
Abstract: GBA2, the non-lysosomal β-glucosylceramidase, is an enzyme involved in glucosylceramide metabolism. Pharmacological inhibition of GBA2 by N-alkyl iminosugars is well tolerated and benefits patients suffering from Sandhoff and Niemann–Pick type C diseases, and GBA2 inhibitors have been proposed as candidate-clinical drugs for the treatment of parkinsonism. With the ultimate goal to unravel the role of GBA2 in (patho)physiology, we sought to develop a GBA2-specific activity-based probe (ABP). A library of probes was tested for activity against GBA2 and the two other cellular retaining β-glucosidases, lysosomal GBA1 and cytosolic GBA3. We show that β-D-arabinofuranosyl cyclitol aziridine (β-D-Araf aziridine) reacts with the GBA2 active site nucleophile to form a covalent and irreversible bond. Fluorescent β-D-Araf aziridine probes potently and selectively label GBA2 both in vitro and in cellulo, allowing for visualization of the localization of overexpressed GBA2 using fluorescence microscopy. Co-staining with an antibody selective for the lysosomal β-glucosylceramidase GBA1, shows distinct subcellular localization of the two enzymes. We proffer our ABP technology for further delineating the role and functioning of GBA2 in disease and propose the β-D-Araf aziridine scaffold as a good starting point for the development of GBA2-specific inhibitors for clinical development.
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Sep 2024
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I03-Macromolecular Crystallography
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Diamond Proposal Number(s):
[32736]
Abstract: The human Golgi α-mannosidase, hGMII, removes two mannose residues from GlcNAc-Man5GlcNAc2 to produce GlcNAcMan3GlcNAc2, the precursor of all complex N-glycans including tumour-associated ones. The natural product GMII inhibitor, swainsonine, blocks processing of cancer-associated N-glycans, but also inhibits the four other human α-mannosidases, rendering it unsuitable for clinical use. Our previous structure-guided screening of iminosugar pyrrolidine and piperidine fragments identified two micromolar hGMII inhibitors occupying the enzyme active pockets in adjacent, partially overlapping sites. Here we demonstrate that fusing these fragments yields swainsonine-configured indolizidines featuring a C3-substituent that act as selective hGMII inhibitors. Our structure-guided GMII-selective inhibitor design complements a recent combinatorial approach that yielded similarly configured and substituted indolizidine GMII inhibitors, and holds promise for the potential future development of anti-cancer agents targeting Golgi N-glycan processing.
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Sep 2024
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I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
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Tim P.
Ofman
,
Jurriaan J. A.
Heming
,
Alba
Nin-Hill
,
Florian
Küllmer
,
Elisha
Moran
,
Megan
Bennett
,
Roy
Steneker
,
Anne-Mei
Klein
,
Gijs
Ruijgrok
,
Ken
Kok
,
Zach W. B.
Armstrong
,
Johannes M. F. G.
Aerts
,
Gijsbert A.
Van Der Marel
,
Carme
Rovira
,
Gideon J.
Davies
,
Marta
Artola
,
Jeroen D. C.
Codée
,
Hermen S.
Overkleeft
Diamond Proposal Number(s):
[32736, 24948]
Open Access
Abstract: Glycoside hydrolases (glycosidases) take part in myriad biological processes and are important therapeutic targets. Competitive and mechanism-based inhibitors are useful tools to dissect their biological role and comprise a good starting point for drug discovery. The natural product, cyclophellitol, a mechanism-based, covalent and irreversible retaining β-glucosidase inhibitor has inspired the design of diverse α- and β-glycosidase inhibitor and activity-based probe scaffolds. Here, we sought to deepen our understanding of the structural and functional requirements of cyclophellitol-type compounds for effective human α-glucosidase inhibition. We synthesized a comprehensive set of α-configured 1,2- and 1,6-cyclophellitol analogues bearing a variety of electrophilic traps. The inhibitory potency of these compounds was assessed towards both lysosomal and ER retaining α-glucosidases. These studies revealed the 1,6-cyclophellitols to be the most potent retaining α-glucosidase inhibitors, with the nature of the electrophile determining inhibitory mode of action (covalent or non-covalent). DFT calculations support the ability of the 1,6-cyclophellitols, but not the 1,2-congeners, to adopt conformations that mimic either the Michaelis complex or transition state of α-glucosidases.
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Apr 2024
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I03-Macromolecular Crystallography
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Valentina
Borlandelli
,
Wendy
Offen
,
Olga
Moroz
,
Alba
Nin-Hill
,
Nicholas
Mcgregor
,
Lars
Binkhorst
,
Akihiro
Ishiwata
,
Zachary
Armstrong
,
Marta
Artola
,
Carme
Rovira
,
Gideon J.
Davies
,
Herman S.
Overkleeft
Diamond Proposal Number(s):
[24948]
Open Access
Abstract: GH127 and GH146 microorganismal retaining β-l-arabinofuranosidases, expressed by human gut microbiomes, feature an atypical catalytic domain and an unusual mechanism of action. We recently reported that both Bacteroides thetaiotaomicron BtGH146 and Bifidobacterium longum HypBA1 are inhibited by β-l-arabinofuranosyl cyclophellitol epoxide, supporting the action of a zinc-coordinated cysteine as a catalytic nucleophile, where in most retaining GH families, an aspartate or glutamate is employed. This work presents a panel of β-l-arabinofuranosyl cyclophellitol epoxides and aziridines as mechanism-based BtGH146/HypBA1 inhibitors and activity-based probes. The β-l-arabinofuranosyl cyclophellitol aziridines both inhibit and label β-l-arabinofuranosidase efficiently (however with different activities), whereas the epoxide-derived probes favor BtGH146 over HypBA1. These findings are accompanied by X-ray structural analysis of the unmodified β-l-arabinofuranosyl cyclophellitol aziridine in complex with both isozymes, which were shown to react by nucleophilic opening of the aziridine, at the pseudoanomeric carbon, by the active site cysteine nucleophile to form a stable thioether bond. Altogether, our activity-based probes may serve as chemical tools for the detection and identification of low-abundance β-l-arabinofuranosidases in complex biological samples.
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Dec 2023
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I03-Macromolecular Crystallography
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Alexandra
Males
,
Ken
Kok
,
Alba
Nin-Hill
,
Nicky
De Koster
,
Sija
Van Den Beukel
,
Thomas J. M.
Beenakker
,
Gijsbert A.
Van Der Marel
,
Jeroen D. C.
Codée
,
Johannes M. F. G.
Aerts
,
Herman S.
Overkleeft
,
Carme
Rovira
,
Gideon J.
Davies
,
Marta
Artola
Diamond Proposal Number(s):
[24948]
Open Access
Abstract: Class I inverting exo-acting α-1,2-mannosidases (CAZY family GH47) display an unusual catalytic itinerary featuring ring-flipped mannosides, 3S1 → 3H4‡ → 1C4. Conformationally locked 1C4 compounds, such as kifunensine, display nanomolar inhibition but large multigene GH47 mannosidase families render specific “isoform-dependent” inhibition impossible. Here we develop a bump-and-hole strategy in which a new mannose-configured 1,6-trans-cyclic sulfamidate inhibits α-D-mannosidases by virtue of its 1C4 conformation. This compound does not inhibit the wild-type GH47 model enzyme by virtue of a steric clash, a “bump”, in the active site. An L310S (a conserved residue amongst human GH47 enzymes) mutant of the model Caulobacter GH47 awoke 574 nM inhibition of the previously dormant inhibitor, confirmed by structural analysis of a 0.97 Å structure. Considering that L310 is a conserved residue amongst human GH47 enzymes, this work provides a unique framework for future biotechnological studies on N-glycan maturation and ER associated degradation by isoform-specific GH47 α-D-mannosidase inhibition through a bump-and-hole approach.
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Nov 2023
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I03-Macromolecular Crystallography
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Daniël
Van Der Gracht
,
Rhianna J.
Rowland
,
Véronique
Roig-Zamboni
,
Maria J.
Ferraz
,
Max
Louwerse
,
Paul P.
Geurink
,
Johannes M. F. G.
Aerts
,
Gerlind
Sulzenbacher
,
Gideon J.
Davies
,
Herman S.
Overkleeft
,
Marta
Artola
Diamond Proposal Number(s):
[24948]
Open Access
Abstract: Lysosomal exoglycosidases are responsible for processing endocytosed glycans from the non-reducing end to produce the corresponding monosaccharides. Genetic mutations in a particular lysosomal glycosidase may result in accumulation of its particular substrate, which may cause diverse lysosomal storage disorders. The identification of effective therapeutic modalities to treat these diseases is a major yet poorly realised objective in biomedicine. One common strategy comprises the identification of effective and selective competitive inhibitors that may serve to stabilize the proper folding of the mutated enzyme, either during maturation and trafficking to, or residence in, endo-lysosomal compartments. The discovery of such inhibitors is greatly aided by effective screening assays, the development of which is the focus of the here-presented work. We developed and applied fluorescent activity-based probes reporting on either human GH30 lysosomal glucosylceramidase (GBA1, a retaining β-glucosidase) or GH31 lysosomal retaining α-glucosidase (GAA). FluoPol-ABPP screening of our in-house 358-member iminosugar library yielded compound classes selective for either of these enzymes. In particular, we identified a class of N-alkyldeoxynojirimycins that inhibit GAA, but not GBA1, and that may form the starting point for the development of pharmacological chaperone therapeutics for the lysosomal glycogen storage disease that results from genetic deficiency in GAA: Pompe disease.
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Aug 2023
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I03-Macromolecular Crystallography
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Diamond Proposal Number(s):
[24948]
Open Access
Abstract: Degradation of the extracellular matrix (ECM) supports tissue integrity and homeostasis, but is also a key factor in cancer metastasis. Heparanase (HPSE) is a mammalian ECM-remodeling enzyme with β-D-endo-glucuronidase activity overexpressed in several malignancies, and is thought to facilitate tumor growth and metastasis. By this virtue, HPSE is considered an attractive target for the development of cancer therapies, yet to date no HPSE inhibitors have progressed to the clinic. Here we report on the discovery of glucurono-configured cyclitol derivatives featuring simple substituents at the 4-O-position as irreversible HPSE inhibitors. We show that these compounds, unlike glucurono-cyclophellitol, are selective for HPSE over β-D-exo-glucuronidase (GUSB), also in platelet lysate. The observed selectivity is induced by steric and electrostatic interactions of the substituents at the 4-O-position. Crystallographic analysis supports this rationale for HPSE selectivity, and computer simulations provide insights in the conformational preferences and binding poses of the inhibitors, which we believe are good starting points for the future development of HPSE-targeting antimetastatic cancer drugs.
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Dec 2022
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I04-Macromolecular Crystallography
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Ken
Kok
,
Chi-Lin
Kuo
,
Rebecca E.
Katzy
,
Lindsey T.
Lelieveld
,
Liang
Wu
,
Véronique
Roig-Zamboni
,
Gijsbert A.
Van Der Marel
,
Jeroen D. C.
Codée
,
Gerlind
Sulzenbacher
,
Gideon J.
Davies
,
Herman S.
Overkleeft
,
Johannes M. F. G.
Aerts
,
Marta
Artola
Open Access
Abstract: α-Glucosidase inhibitors are potential therapeutics for the treatment of diabetes, viral infections, and Pompe disease. Herein, we report a 1,6-epi-cyclophellitol cyclosulfamidate as a new class of reversible α-glucosidase inhibitors that displays enzyme inhibitory activity by virtue of its conformational mimicry of the substrate when bound in the Michaelis complex. The α-d-glc-configured cyclophellitol cyclosulfamidate 4 binds in a competitive manner the human lysosomal acid α-glucosidase (GAA), ER α-glucosidases, and, at higher concentrations, intestinal α-glucosidases, displaying an excellent selectivity over the human β-glucosidases GBA and GBA2 and glucosylceramide synthase (GCS). Cyclosulfamidate 4 stabilizes recombinant human GAA (rhGAA, alglucosidase alfa, Myozyme) in cell medium and plasma and facilitates enzyme trafficking to lysosomes. It stabilizes rhGAA more effectively than existing small-molecule chaperones and does so in vitro, in cellulo, and in vivo in zebrafish, thus representing a promising therapeutic alternative to Miglustat for Pompe disease.
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Aug 2022
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I02-Macromolecular Crystallography
I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
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Gideon J.
Davies
,
Rhianna J.
Rowland
,
Yurong
Chen
,
Imogen
Breen
,
Liang
Wu
,
Wendy A.
Offen
,
Thomas
Beenakker
,
Qin
Su
,
Adrianus M. C. H.
Van Den Nieuwendijk
,
Johannes M. F. G.
Aerts
,
Marta
Artola
,
Herman S.
Overkleeft
Diamond Proposal Number(s):
[13587, 18598]
Open Access
Abstract: Gaucher disease (GD) is a lysosomal storage disorder caused by inherited deficiencies in β-glucocerebrosidase (GBA). Current treatments require rapid disease diagnosis and a means of monitoring therapeutic efficacy, both of which may be supported by the use of GBA-targeting activity-based probes (ABPs). Here, we report the synthesis and structural analysis of a range of cyclophellitol epoxide and aziridine inhibitors and ABPs for GBA. We demonstrate their covalent mechanism-based mode of action and uncover binding of the new N- functionalised aziridines to the ligand binding cleft. These inhibitors became scaffolds for the development of ABPs; the O6-fluorescent tags of which bind in an allosteric site at the dimer interface. Considering GBA’s preference for O6- and N -functionalised reagents, we synthesised a bi-functional aziridine ABP which we hoped would offer a more powerful imaging agent. Whilst this ABP binds to two unique active site clefts of GBA, no further benefit in potency was achieved over our first generation ABPs. Nevertheless, such ABPs should serve useful in the study of GBA in relation to GD and inform the design of future probes.
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Sep 2021
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I03-Macromolecular Crystallography
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Nicholas G. S.
Mcgregor
,
Joan
Coines
,
Valentina
Borlandelli
,
Satoko
Amaki
,
Marta
Artola
,
Alba
Nin‐hill
,
Daniël
Linzel
,
Chihaya
Yamada
,
Takatoshi
Arakawa
,
Akihiro
Ishiwata
,
Yukishige
Ito
,
Gijsbert A.
Marel
,
Jeroen D. C.
Codée
,
Shinya
Fushinobu
,
Herman S.
Overkleeft
,
Carme
Rovira
,
Gideon J.
Davies
Diamond Proposal Number(s):
[18598]
Abstract: The recent discovery of zinc‐dependent retaining glycoside hydrolases (GHs), with active sites built around a Zn(Cys)3(Glu) coordination complex, has presented unresolved mechanistic questions. In particular, the proposed mechanism, depending on a Zn‐coordinated cysteine nucleophile and passing through a thioglycosyl enzyme intermediate, remains controversial. This is primarily due to the expected stability of the intermediate C−S bond. To facilitate the study of this atypical mechanism, we report the synthesis of a cyclophellitol‐derived β‐l‐arabinofuranosidase inhibitor, hypothesised to react with the catalytic nucleophile to form a non‐hydrolysable adduct analogous to the mechanistic covalent intermediate. This β‐l‐arabinofuranosidase inhibitor reacts exclusively with the proposed cysteine thiol catalytic nucleophiles of representatives of GH families 127 and 146. X‐ray crystal structures determined for the resulting adducts enable MD and QM/MM simulations, which provide insight into the mechanism of thioglycosyl enzyme intermediate breakdown. Leveraging the unique chemistry of cyclophellitol derivatives, the structures and simulations presented here support the assignment of a zinc‐coordinated cysteine as the catalytic nucleophile and illuminate the finely tuned energetics of this remarkable metalloenzyme clan.
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Feb 2021
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