Publications by authors named "Chengyong Wu"

20 Publications

  • Page 1 of 1

A distinct structure of Cas1-Cas2 complex provides insights into the mechanism for the longer spacer acquisition in Pyrococcus furiosus.

Int J Biol Macromol 2021 Apr 14;183:379-386. Epub 2021 Apr 14.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, PR China. Electronic address:

In the adaptation stage of CRISPR-Cas systems, the Cas1-Cas2 integrase captures and integrates new invader-derived spacers into the CRISPR locus, serving as a molecular memory of prior infection. As of yet, the structural information of Cas1-Cas2 complex is available only for two species. Here we present the crystal structure of Cas1-Cas2 complex of Pyrococcus furiosus, which showed a distinct architecture from the known Cas1-Cas2 complexes. The shorter C-terminal tail of Pfu Cas2 directs the Cas1 dimers go in the opposite direction, resulting in a different prespacer binding mode. Based on our structural and mutagenesis results, we modeled a prespacer with a shorter duplex and longer 3' overhangs to bind Pfu Cas1-Cas2 complex. The prespacer preference was confirmed by EMSA, fluorescence polarization, and in vitro integration assays. This model provides a potential explanation for the longer spacer acquisition observed in P. furiosus when deleting both cas4 genes. Our study highlights the diversity of the CRISPR adaptation module.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.04.074DOI Listing
April 2021

Mechanisms of spacer acquisition by sequential assembly of the adaptation module in Synechocystis.

Nucleic Acids Res 2021 03;49(5):2973-2984

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China.

CRISPR-Cas immune systems process and integrate short fragments of DNA from new invaders as spacers into the host CRISPR locus to establish molecular memory of prior infection, which is also known as adaptation in the field. Some CRISPR-Cas systems rely on Cas1 and Cas2 to complete the adaptation process, which has been characterized in a few systems. In contrast, many other CRISPR-Cas systems require an additional factor of Cas4 for efficient adaptation, the mechanism of which remains less understood. Here we present biochemical reconstitution of the Synechocystis sp. PCC6803 type I-D adaptation system, X-ray crystal structures of Cas1-Cas2-prespacer complexes, and negative stained electron microscopy structure of the Cas4-Cas1 complex. Cas4 and Cas2 compete with each other to interact with Cas1. In the absence of prespacer, Cas4 but not Cas2 assembles with Cas1 into a very stable complex for processing the prespacer. Strikingly, the Cas1-prespacer complex develops a higher binding affinity toward Cas2 to form the Cas1-Cas2-prespacer ternary complex for integration. Together, we show a two-step sequential assembly mechanism for the type I-D adaptation module of Synechocystis, in which Cas4-Cas1 and Cas1-Cas2 function as two exclusive complexes for prespacer processing, capture, and integration.
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http://dx.doi.org/10.1093/nar/gkab105DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7969031PMC
March 2021

A Rationale for Drug Design Provided by Co-Crystal Structure of IC261 in Complex with Tubulin.

Molecules 2021 Feb 10;26(4). Epub 2021 Feb 10.

Department of Clinical Research Management, Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, West China Hospital, Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China.

Microtubules composed of α/β tubulin heterodimers are an essential part of the cytoskeleton of eukaryotic cells and are widely regarded as targets for cancer chemotherapy. IC261, which is discovered as an ATP-competitive inhibitor of serine/threonine-specific casein kinase 1 (CK1), has shown its inhibitory activity on microtubule polymerization in recent studies. However, the structural information of the interaction between tubulin and IC261 is still unclear. Here, we provided a high-resolution (2.85 Å) crystal structure of tubulin and IC261 complex, revealed the intermolecular interaction between tubulin and IC261, and analyzed the structure-activity relationship (SAR). Subsequently, the structure of tubulin-IC261 complex was compared with tubulin-colchicine complex to further elucidate the novelty of IC261. Furthermore, eight optimal candidate compounds of new IC261-based microtubule inhibitors were obtained through molecular docking studies. In conclusion, the co-crystal structure of tubulin-IC261 complex paves a way for the design and development of microtubule inhibitor drugs.
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http://dx.doi.org/10.3390/molecules26040946DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916759PMC
February 2021

Structure-Guided Discovery of a Potent and Selective Cell-Active Inhibitor of SETDB1 Tudor Domain.

Angew Chem Int Ed Engl 2021 04 8;60(16):8760-8765. Epub 2021 Mar 8.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, P. R. China.

SET domain bifurcated protein 1 (SETDB1) is a histone lysine methyltransferase that promotes the silencing of some tumour suppressor genes and is overexpressed in many cancers. SETDB1 contains a unique tandem tudor domain (TTD) that recognizes histone H3 sequences containing both methylated and acetylated lysines. Beginning with the identification of a hit compound (Cpd1), we discovered the first potent and selective small molecule SETDB1-TTD inhibitor (R,R)-59 through stepwise structure-guided optimization. (R,R)-59 showed a K value of 0.088±0.045 μM in the ITC assay. The high potency of (R,R)-59 was well explained by the cocrystal structure of the (R,R)-59-TTD complex. (R,R)-59 is an endogenous binder competitive inhibitor. Evidence has also demonstrated its cellular target engagement. Interestingly, the enantiomer (S,S)-59 did not show activity in all the assays, highlighting the potential of (R,R)-59 as a tool compound in exploring the biological functions of SETDB1-TTD.
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http://dx.doi.org/10.1002/anie.202017200DOI Listing
April 2021

Light-up RNA aptamer signaling-CRISPR-Cas13a-based mix-and-read assays for profiling viable pathogenic bacteria.

Biosens Bioelectron 2021 Mar 16;176:112906. Epub 2020 Dec 16.

College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, 610065, China.

Viable pathogenic bacteria cause serious human diseases via systemic infections and food poisoning. Herein, we constructed a light-up RNA aptamer signaling-CRISPR-Cas13a assay enabling mix-and-read detection of viable pathogenic bacteria. Directly targeting pathogen RNAs via CRISPR-Cas13a allows precisely discriminating viable bacteria from dead bacteria. We introduced a light-up RNA aptamer, Broccoli, serving as the substate of activated CRISPR-Cas13a to monitor the presence of pathogen RNAs, eliminating the need to use chemically labeled RNA substrate. Sequentially, the assay allows a reverse transcription-free, nucleic acid amplification-free, and label-free quantification of RNA targets and viable pathogenic bacteria. It could detect as low as 10 CFU of Bacillus cereus and precisely quantify viable bacteria with a content ranging from 0% to 100% in 10 CFU total bacteria. The quantification of viable bacteria allows more accurately estimating the ability of B. cereus to spoil food. The RNA assay promises its use in point-of-use detection of viable pathogens and biosafety control.
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http://dx.doi.org/10.1016/j.bios.2020.112906DOI Listing
March 2021

Label-free DNAzyme assays for dually amplified and one-pot detection of lead pollution.

J Hazard Mater 2021 Mar 7;406:124790. Epub 2020 Dec 7.

College of Biomass Science and Engineering, Healthy Food Evaluation Research Center and Key Laboratory of Food Science and Technology of Ministry of Education of Sichuan Province, Sichuan University, Chengdu 610065, China.

Lead pollution in water and soil often transfers to food, advocating tools for on-site detection of lead pollution to ensure both environmental and food safety. We proposed a label-free, dually amplified and homogeneous DNAzyme assay for sensitive and one-pot detection of lead pollution. Instead of using chemically modified DNA substrate, a structure-response digestion process was introduced to monitor Pb presence-induced cleavage process of unlabeled substrate, further amplifying the response signals and eliminating the use of labeled DNA probes. The DNAzyme assay allowed to detect Pb as low as 0.12 nM and endued a dynamic range from 0.1 nM to 30 nM. In addition, it can specifically identify Pb among other metal ions. We demonstrated that the DNAzyme assay can precisely detect Pb in tap water, milk and fish. Thus, the DNAzyme assay is promising for on-site monitoring lead pollution risk and ensuring environmental and food safety.
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http://dx.doi.org/10.1016/j.jhazmat.2020.124790DOI Listing
March 2021

High-resolution X-ray structure of three microtubule-stabilizing agents in complex with tubulin provide a rationale for drug design.

Biochem Biophys Res Commun 2021 01 30;534:330-336. Epub 2020 Nov 30.

Cancer Center, West China Hospital, Sichuan University, And Collaborative Innovation Center of Biotherapy, Chengdu, 610041, People's Republic of China; Precision Medicine Research Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, 610041, People's Republic of China. Electronic address:

Microtubule is a key component of cytoskeleton and has been considered as an important target for the treatment of cancer. In particular, the tubulin taxane-site inhibitors such as taxol analogs and epothilones have achieved great success in clinical trials. However, the structural basis of many taxane-site inhibitors is still lacking in exploring their mechanism of action. We here reported crystal complex structures for three taxane-site inhibitors, Ixabepilone, Epothilone B, and Epothilone D, which were determined to 2.4 Å, 2.4 Å, and 2.85 Å, respectively. The crystal structures revealed that these taxane-site inhibitors possess similar binding modes to that of Epothilone A at the taxane site, e.g. making critical hydrogen-bonding interactions with multiple residues on the M-loop, which facilitating the tubulin polymerization. Furthermore, we summarized the binding modes of almost all taxane-site inhibitors and identified novel taxane-site ligands with simpler chemical structures through virtual screening. On this basis, new derivatives with higher binding affinity to tubulin were designed and developed, which can form additional hydrogen bond interactions with tubulin. Overall, this work determined the mechanism of action of epothilones and provided a structural basis to design reasonably novel taxane-site inhibitors with simpler structure and improved pharmacokinetic properties.
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http://dx.doi.org/10.1016/j.bbrc.2020.11.082DOI Listing
January 2021

The high-resolution X-ray structure of vinca-domain inhibitors of microtubules provides a rational approach for drug design.

FEBS Lett 2021 Jan 10;595(2):195-205. Epub 2021 Jan 10.

Cancer Center, West China Hospital, Sichuan University, Chengdu, China.

Tubulin vinca-domain ligands can inhibit microtubule polymerization, causing cell death in mitosis, and their potential against multiple cancer types has been demonstrated. However, due to drug resistance and toxicities, development of novel vinca-domain ligands is still needed. In this study, we determined the high-resolution crystal structures of vinorelbine, YXD, and Phomopsin A in complex with tubulin at 2.5 Å. Additionally, we recapitulated all previously published high-resolution crystal structures of the vinca binding site to reveal critical residues and the molecular mechanism of vinca-domain ligands interacting with tubulin. Furthermore, we designed putatively novel triazolopyrimidine derivatives by introducing secondary amine groups to establish salt-bridge and H-bond interactions with Asp179 and Asn329 . Our studies provided the structural basis for designing novel tubulin vinca-domain ligands.
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http://dx.doi.org/10.1002/1873-3468.14003DOI Listing
January 2021

Metal-induced G-quadruplex polymorphism for ratiometric and label-free detection of lead pollution in tea.

Food Chem 2021 May 20;343:128425. Epub 2020 Oct 20.

College of Biomass Science and Engineering, Healthy Food Evaluation Research Center and Key Laboratory of Food Science and Technology of Ministry of Education of Sichuan Province, Sichuan University, Chengdu 610065, China. Electronic address:

Lead pollution are critical concerns for food safety and human health. Herein, a ratiometric metal-induced G-quadruplex polymorphism was introduced to construct aptamer probes, enabling label-free and ratiometric detection of lead in tea, thus is promising for on-site detection of lead pollution. The key feature of the aptamer probe is the synergistic utilization of the dual-wavelength fluorescent signal outputs from a G-quadruplex specific dye and a DNA intercalation dye under a single-wavelength excitation, leading to a more stable and reliable recognition of Pb than that of analyses based on single fluorescent reporter. The aptamer probe allowed to a mix-and-read, rapid, cost-effective detection of Pb with high specificity and accuracy. Pb analysis in tap water and tea exhibited good performance with recovery rates of 92.3%-109.0%. The adoption of ratiometric metal-induced G-quadruplex polymorphism would be a compelling design strategy for constructing robust aptasensor, facilitating the translation of aptamer for food safety control.
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http://dx.doi.org/10.1016/j.foodchem.2020.128425DOI Listing
May 2021

Unraveling the molecular mechanism of BNC105, a phase II clinical trial vascular disrupting agent, provides insights into drug design.

Biochem Biophys Res Commun 2020 Feb 18. Epub 2020 Feb 18.

Department of Respiratory and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, 610041, PR China. Electronic address:

Microtubules are made up of tubulin protein and play a very important part in numerous cellular events of eukaryotic cells, which is why they are seen as attractive targets for tumor chemotherapy. BNC105, a known vascular targeting agent, has entered in phase II clinical trials. It has previously been confirmed that BNC105 is an effective microtubule targeting agent for various cancers. BNC105 exhibits selectivity for tumor cells, elicits vascular disrupting effects, and inhibits tumor growth. However, the molecular mechanism of BNC105 is still elusive. Herein, the crystal structure of BNC105 in complex with tubulin protein is revealed, demonstrating the its interaction with the colchicine binding site. In order to thoroughly evaluate its molecular mechanism from a structural-activity-relationship standpoint, the binding mode of tubulin to BNC-105 is compared with colchicine, CA-4 and other BNC-105 derivatives. Our study not only confirms the detailed interactions of the BNC105-tubulin complex, but also offer substantial structural foundation for the design and development of novel benzo[b]furan derivatives as microtubule targeting agents.
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http://dx.doi.org/10.1016/j.bbrc.2019.12.083DOI Listing
February 2020

Structure-Based Development of (1-(3'-Mercaptopropanamido)methyl)boronic Acid Derived Broad-Spectrum, Dual-Action Inhibitors of Metallo- and Serine-β-lactamases.

J Med Chem 2019 08 17;62(15):7160-7184. Epub 2019 Jul 17.

Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy , Sichuan University , Sichuan 610041 , China.

The emergence and spread of bacterial pathogens acquired metallo-β-lactamase (MBL) and serine-β-lactamase (SBL) medicated β-lactam resistance gives rise to an urgent need for the development of new dual-action MBL/SBL inhibitors. Application of a pharmacophore fusion strategy led to the identification of (2')-(1-(3'-mercapto-2'-methylpropanamido)methyl)boronic acid () as a new dual-action inhibitor, which manifests broad-spectrum inhibition to representative MBL/SBL enzymes, including the widespread VIM-2 and KPC-2. Guided by the VIM-2: and KPC-2: complex structures, further structural optimization yielded new, more potent dual-action inhibitors. Selectivity studies indicated that the inhibitors had no apparent inhibition to human angiotensin-converting enzyme-2 and showed selectivity across serine hydrolyases in and human HEK293T cells labeled by the activity-based probe TAMRA-FP. Moreover, the inhibitors displayed potentiation of meropenem efficacy against MBL- or SBL-positive clinical isolates without apparent cytotoxicity. This work will aid efforts to develop new types of clinically useful dual-action inhibitors targeting MBL/SBL enzymes.
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http://dx.doi.org/10.1021/acs.jmedchem.9b00735DOI Listing
August 2019

Discovery of Pyrrolo[3,2- d]pyrimidin-4-one Derivatives as a New Class of Potent and Cell-Active Inhibitors of P300/CBP-Associated Factor Bromodomain.

J Med Chem 2019 05 30;62(9):4526-4542. Epub 2019 Apr 30.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital , Sichuan University , Chengdu 610041 , P. R. China.

Herein, we report the discovery of a series of new P300/CBP-associated factor (PCAF) bromodomain (BRD) inhibitors, which were obtained through a hit discovery process and subsequent structure-based optimization and structure-activity relationship analyses toward a retrieved hit compound (12). Among these inhibitors, ( R, R)-36n is the most potent one with an IC of 7 nM in homogeneous time-resolved fluorescence assay and a K of 78 nM in isothermal titration calorimetry assay. This compound also exhibited activity against GCN5 and FALZ, but weak or no activity against other 29 BRD proteins and 422 kinases, indicating considerable selectivity. X-ray cocrystal structure analysis revealed the molecular interaction mode and the precise stereochemistry required for bioactivity. Cellular activity, preliminary RNA-seq analysis, and pharmacokinetic properties were also examined for this compound. Collectively, this study provides a versatile tool molecule to explore molecular mechanisms of PCAF BRD regulation and also offers a new lead compound for drug discovery targeting PCAF.
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http://dx.doi.org/10.1021/acs.jmedchem.9b00096DOI Listing
May 2019

Molecular mechanism of crolibulin in complex with tubulin provides a rationale for drug design.

Biochem Biophys Res Commun 2019 04 22;511(2):381-386. Epub 2019 Feb 22.

State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, 610041, People's Republic of China. Electronic address:

Microtubules (MTs) is one of the most important proteins in eukaryotic cells and plays a key role in the maintenance of cell morphology and cell division. The discovery and development of small molecule drugs targeting MTs has always been an important direction of anti-cancer research. Nowadays 4-Aryl-4H-chromenes have emerged as potent microtubule-targeting agents (MTAs) for various cancers. Crolibulin, a derivative of 4-Aryl-4H-chromenes, which has been progressed to Phase I/II clinical testing's for anaplastic thyroid cancer with the National Cancer Institute. However, the design and development of 4-Aryl-4H-chromenes family drugs have been hindered for a long time by the lack of structural information of the tubulin-agent complex. Here we report a 2.5 Å crystal structure of tubulin complexed with crolibulin. This complex structure reveals the interactions between crolibulin and tubulin, helps explain the results of the structure-activity-relationship (SAR) studies and provides a solid structural basis for the design and development of new 4-Aryl-4H-chromenes derivatives as MTAs.
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http://dx.doi.org/10.1016/j.bbrc.2019.02.064DOI Listing
April 2019

The bromodomain protein BRD4 positively regulates necroptosis via modulating MLKL expression.

Cell Death Differ 2019 Oct 15;26(10):1929-1941. Epub 2019 Jan 15.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu, 610041, China.

Necroptosis is a programmed form of necrotic cell death, which is tightly regulated by the necroptotic signaling pathway containing receptor-interacting protein (RIP)1, RIP3, and mixed-lineage kinase domain-like (MLKL) protein. In addition to the RIP1-RIP3-MLKL axis, other factors regulating necroptosis are still largely unknown. Here a cell-based small-molecule screening led to the finding that BET inhibitors protected cells from necroptosis in the TNFα/Smac-mimetic/Z-VAD-FMK (TSZ)-induced cell necroptosis model. Mechanistic studies revealed that BET inhibitors acted by downregulating MLKL expression. Further research demonstrated that BRD4, IRF1, P-TEFb, and RNA polymerase II formed a transcription complex to regulate the expression of MLKL, and BET inhibitors interfered with the transcription complex formation. In necroptosis-related disease model, the BET inhibitor JQ-1 showed promising therapeutic effects. Collectively, our studies establish, for the first time, BRD4 as a new epigenetic factor regulating necroptosis, and highlight the potential of BET inhibitors in the treatment of necroptosis-related diseases.
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http://dx.doi.org/10.1038/s41418-018-0262-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6748082PMC
October 2019

X-ray crystal structure guided discovery of new selective, substrate-mimicking sirtuin 2 inhibitors that exhibit activities against non-small cell lung cancer cells.

Eur J Med Chem 2018 Jul 19;155:806-823. Epub 2018 Jun 19.

Key Laboratory of Drug Targeting and Drug Delivery System of Ministry of Education, West China School of Pharmacy, and State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, 610041, China. Electronic address:

Human sirtuin 2 (SIRT2) is a nicotinamide adenine dinucleotide (NAD)-dependent deacylase, and is implicated in human diseases including cancer. Selective small-molecule inhibitors for SIRT2 are sought as chemical tools and potential therapeutics. Here we report the X-ray crystal structure guided structure-activity relationship studies of new N-(3-(phenoxymethyl)phenyl)acetamide derivatives with SIRT2, which led to the identification of potent, selective SIRT2 inhibitors. Crystallographic analyses reveal that the new inhibitors act via inducing the formation of an enlarged hydrophobic pocket and particularly mimicking the interactions made by myristoylated-lysine substrates. The most potent inhibitor 24a could dose-dependently elevate the acetylation level of α-tubulin in the non-small cell lung cancer H441 cells, which have a high expression level of SIRT2 as determinated by Western blotting analyses. Further cellular assays reveal that 24a restrains cell growth mainly through inhibiting cellular proliferation rather than inducing apoptosis. Moreover, 24a could suppress the migration and invasion of H441 cells. These results provide an excellent basis for further development of new potent, selective, and cell active SIRT2 inhibitors as chemical tools and potential therapeutics for SIRT2-driven non-small cell lung cancers.
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http://dx.doi.org/10.1016/j.ejmech.2018.06.041DOI Listing
July 2018

((S)-3-Mercapto-2-methylpropanamido)acetic acid derivatives as metallo-β-lactamase inhibitors: Synthesis, kinetic and crystallographic studies.

Eur J Med Chem 2018 Feb 11;145:649-660. Epub 2018 Jan 11.

Key Laboratory of Drug Targeting and Drug Delivery System of Ministry of Education, West China School of Pharmacy, Sichuan University, Sichuan 610041, China. Electronic address:

The emergence and global spread of metallo-β-lactamase (MBL) mediated resistance to almost all β-lactam antibacterials poses a serious threat to public health. Since no clinically useful MBL inhibitors have been reported, there is an urgent need to develop new potent broad-spectrum MBL inhibitors effective against antibacterial resistance. Herein, we synthesized a set of 2-substituted ((S)-3-mercapto-2-methylpropanamido) acetic acid derivatives, some of which displayed potent inhibition with high ligand efficiency to the clinically relevant MBL subtypes, Verona Integron-encoded MBL (VIM)-2 and New Delhi MBL (NDM)-1. Kinetic studies revealed that the inhibitors are not strong zinc chelators in solution, and they bind reversibly to VIM-2 but dissociate very slowly. Crystallographic analyses revealed that they inhibit VIM-2 via chelating the active site zinc ions and interacting with catalytically important residues. Further cell- and zebrafish-based assays revealed that the inhibitors slightly increase susceptibility of E. coli cells expressing VIM-2 to meropenem, and they have no apparent toxicity to the viability of HEK293T cells and the zebrafish embryogenesis.
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http://dx.doi.org/10.1016/j.ejmech.2018.01.032DOI Listing
February 2018

Structure of a benzylidene derivative of 9(10H)-anthracenone in complex with tubulin provides a rationale for drug design.

Biochem Biophys Res Commun 2018 01 2;495(1):185-188. Epub 2017 Nov 2.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Collaborative Innovation Center of Biotherapy, Chengdu 610041, People's Republic of China. Electronic address:

Microtubules are composed of αβ-tubulin heterodimers and have been treated as highly attractive targets for antitumor drugs. A broad range of agents bind to tubulin and interfere with microtubule assembly, including colchicine binding site inhibitors (CBSIs). Tubulin Polymerization Inhibitor I (TPI1), a benzylidene derivative of 9(10H)-anthracenone, is a CBSI that inhibits the assembly of microtubules. However, for a long time, the design and development of anthracenone family drugs have been hindered by the lack of structural information of the tubulin-agent complex. Here we report a 2.3 Å crystal structure of tubulin complexed with TPI1, the first structure of anthracenone family agents. This complex structure reveals the interactions between TPI1 and tubulin, and thus provides insights into the development of new anthracenone derivatives targeting the colchicine binding site.
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http://dx.doi.org/10.1016/j.bbrc.2017.10.104DOI Listing
January 2018

Structure of 4'-demethylepipodophyllotoxin in complex with tubulin provides a rationale for drug design.

Biochem Biophys Res Commun 2017 11 30;493(1):718-722. Epub 2017 Aug 30.

Cancer Center, West China Hospital, Sichuan University, Collaborative Innovation Center of Biotherapy, Chengdu, 610041, PR China. Electronic address:

Microtubules consists of αβ-tubulin heterodimers and are highly attractive targets for anti-cancer drugs. A broad range of agents have been identified to bind to tubulin and interfere with microtubule assembly, including colchicine binding site inhibitors (CBSIs). Podophyllotoxin is a CBSI that inhibits the assembly of microtubules. However, for a long time, the design and development of podophyllotoxin family drugs have been hindered by the lack of high-resolution structural information of the tubulin-agent complex. We report the first high-resolution (2.8 Å) structure of a podophyllotoxin family agent (4'-demethylepipodophyllotoxin, DMEP) complexed with tubulin and revealed the detailed interactions between DMEP and tubulin. Comparison of this structure and other CBSIs explains previous results of the structure-activity-relationship (SAR) studies, and provides insights into the development of new podophyllotoxin derivatives targeting the colchicine site.
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http://dx.doi.org/10.1016/j.bbrc.2017.08.125DOI Listing
November 2017

Mechanism of microtubule stabilization by taccalonolide AJ.

Nat Commun 2017 06 6;8:15787. Epub 2017 Jun 6.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China.

As a major component of the cytoskeleton, microtubules consist of αβ-tubulin heterodimers and have been recognized as attractive targets for cancer chemotherapy. Microtubule-stabilizing agents (MSAs) promote polymerization of tubulin and stabilize the polymer, preventing depolymerization. The molecular mechanisms by which MSAs stabilize microtubules remain elusive. Here we report a 2.05 Å crystal structure of tubulin complexed with taccalonolide AJ, a newly identified taxane-site MSA. Taccalonolide AJ covalently binds to β-tubulin D226. On AJ binding, the M-loop undergoes a conformational shift to facilitate tubulin polymerization. In this tubulin-AJ complex, the E-site of tubulin is occupied by GTP rather than GDP. Biochemical analyses confirm that AJ inhibits the hydrolysis of the E-site GTP. Thus, we propose that the β-tubulin E-site is locked into a GTP-preferred status by AJ binding. Our results provide experimental evidence for the connection between MSA binding and tubulin nucleotide state, and will help design new MSAs to overcome taxane resistance.
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http://dx.doi.org/10.1038/ncomms15787DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5467209PMC
June 2017

GSTM1 null genotype contributes to increased risk of male infertility: a meta-analysis.

J Assist Reprod Genet 2012 Aug 24;29(8):837-45. Epub 2012 May 24.

Reproductive Medicine Center, Department of Obstetrics and Gynecology, Meizhou People's hospital, Meizhou, 514031, China.

Background: Many studies have investigated the association between Glutathione S-Transferase M 1 (GSTM1) null genotype and risk of male infertility, but the impact of GSTM1 null genotype on infertility risk is unclear owing to the obvious inconsistency among those studies. This study aimed to quantify the strength of association between GSTM1 null genotype and risk of male infertility.

Methods: We searched the PubMed, Embase and Wangfang databases for studies investigating the association between GSTM1 null genotype and risk of male infertility. We estimated pooled odds ratio (OR) with its 95 % confidence interval (95 % CI) to assess this possible association.

Results: Twelve case-control studies with 1, 589 infertility cases and 1, 537 controls were included. Meta-analysis of total 12 studies showed that GSTM1 null genotype was associated with increased risk of male infertility (OR = 1.34, 95%CI 1.02-1.77, P = 0.036). In subgroup analysis of Caucasians, there was also an obvious association between GSTM1 null genotype and increased risk of male infertility (OR = 1.51, 95%CI 1.11-2.05, P = 0.006). Sensitivity analyses by sequential omission of individual studies or omitting studies without high quality did not significantly alter the overall pooled OR. Cumulative meta-analysis further showed a trend of more obvious association as information accumulated. No evidence of publication bias was observed.

Conclusion: Meta-analyses of available data suggest that GSTM1 null genotype contributes to increased risk of male infertility.
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http://dx.doi.org/10.1007/s10815-012-9790-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3430769PMC
August 2012