Selective inhibition of anthrax edema factor by adefovir, a drug for chronic hepatitis B virus infection

Shen, Yuequan; Zhukovskaya, Natalia L.; Zimmer, Michael I.; Soelaiman, Sandriyana; Bergson, Pamela; Wang, Chyung Ru; Gibbs, Craig S.; Tang, Wei-Jen

doi:10.1073/pnas.0306552101

Cited by 101 publications

(112 citation statements)

References 41 publications

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“…We next confirmed that the effects of ET and LT on DC were due to the enzymatic activities of EF and LF using the following specific chemical inhibitors: adefovir dipivoxil (Bis-POM-PMEA) (24) and EGCG, respectively (25). We found that preincubation with Bis-POM-PMEA restored TNF-␣ and IL-12p70 secretions by ET-treated DC to normal levels (Fig.…”

Section: Et and Lt Inhibitors Restore DC Cytokine Secretionsupporting

confidence: 64%

“…6, B and C). The affinity of adefovir diphosphate, the active cellular metabolite of Bis-POM-PMEA for EF-calmodulin complex, is 10-to 500-fold higher than for mammalian host adenylyl cyclase (24); EGCG has been shown to have no toxicity even at concentrations exceeding 100 M in rats and humans (25). The low concentrations used in these experiments and the absence of cell toxicity suggest a specific interaction between inhibitors and their respective targets.…”

Section: Et and Lt Inhibitors Restore DC Cytokine Secretionmentioning

confidence: 87%

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Anthrax Edema Toxin Cooperates with Lethal Toxin to Impair Cytokine Secretion during Infection of Dendritic Cells

Tournier

Quesnel‐Hellmann

Mathieu

et al. 2005

The Journal of Immunology

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Bacillus anthracis secretes two critical virulence factors, lethal toxin (LT) and edema toxin (ET). In this study, we show that murine bone marrow-derived dendritic cells (DC) infected with B. anthracis strains secreting ET exhibit a very different cytokine secretion pattern than DC infected with B. anthracis strains secreting LT, both toxins, or a nontoxinogenic strain. ET produced during infection selectively inhibits the production of IL-12p70 and TNF-α, whereas LT targets IL-10 and TNF-α production. To confirm the direct role of the toxins, we show that purified ET and LT similarly disrupt cytokine secretion by DC infected with a nontoxinogenic strain. These effects can be reversed by specific inhibitors of each toxin. Furthermore, ET inhibits in vivo IL-12p70 and IFN-γ secretion induced by LPS. These results suggest that ET produced during infection impairs DC functions and cooperates with LT to suppress the innate immune response. This may represent a new strategy developed by B. anthracis to escape the host immune response.

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Section: Et and Lt Inhibitors Restore DC Cytokine Secretionsupporting

confidence: 64%

Section: Et and Lt Inhibitors Restore DC Cytokine Secretionmentioning

confidence: 87%

Anthrax Edema Toxin Cooperates with Lethal Toxin to Impair Cytokine Secretion during Infection of Dendritic Cells

Tournier

Quesnel‐Hellmann

Mathieu

et al. 2005

The Journal of Immunology

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135

149

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“…In addition, 2Ј,3Ј-(2,4,6-trinitrophenyl) (TNP)-substituted NTPs are potent inhibitors of mammalian AC (Mou et al, 2006). Furthermore, adefovir, a drug for the treatment of chronic hepatitis B virus infection, is a potent CyaA inhibitor (Shen et al, 2004).…”

mentioning

confidence: 99%

Molecular Analysis of the Interaction of Bordetella pertussis Adenylyl Cyclase with Fluorescent Nucleotides

Göttle¹,

Dove²,

Steindel³

et al. 2007

Molecular Pharmacology

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The calmodulin (CaM)-dependent adenylyl cyclase (AC) toxin from Bordetella pertussis (CyaA) substantially contributes to the pathogenesis of whooping cough. Thus, potent and selective CyaA inhibitors may be valuable drugs for prophylaxis of this disease. We examined the interactions of fluorescent 2Ј,3Ј-Nmethylanthraniloyl (MANT)-, anthraniloyl-and trinitrophenyl (TNP)-substituted nucleotides with CyaA. Compared with mammalian AC isoforms and Bacillus anthracis AC toxin edema factor, nucleotides inhibited catalysis by CyaA less potently. Introduction of the MANT substituent resulted in 5-to 170-fold increased potency of nucleotides. K i values of 3ЈMANT-2Јd-ATP and 2ЈMANT-3Јd-ATP in the AC activity assay using Mn 2ϩ were 220 and 340 nM, respectively. Natural nucleoside 5Ј-triphosphates, guanine-, hypoxanthine-and pyrimidine-MANTand TNP nucleotides and di-MANT nucleotides inhibited CyaA, too. MANT nucleotide binding to CyaA generated fluorescence resonance energy transfer (FRET) from tryptophans Trp69 and Trp242 and multiple tyrosine residues, yielding K d values of 300 nM for 3ЈMANT-2Јd-ATP and 400 nM for 2ЈMANT-3Јd-ATP. Fluorescence experiments and docking approaches indicate that the MANT-and TNP groups interact with Phe306. Increases of FRET and direct fluorescence with MANT nucleotides were strictly CaM-dependent, whereas TNP nucleotide fluorescence upon binding to CyaA increased in the absence of CaM and was actually reduced by CaM. In contrast to lowaffinity MANT nucleotides, even low-affinity TNP nucleotides generated strong fluorescence increases upon binding to CyaA. We conclude that the catalytic site of CyaA possesses substantial conformational freedom to accommodate structurally diverse ligands and that certain ligands bind to CyaA even in the absence of CaM, facilitating future inhibitor design.

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“…It is able to enter into eukaryotic cells where it is activated upon binding to endogenous calmodulin (CaM) to produce supraphysiological levels of cAMP that alter the cell physiology. By targeting immune cells, EF contributes to the virulence of B. anthracis and is therefore considered as a target for anti-anthrax drugs (25)(26)(27)(28).…”

mentioning

confidence: 99%

Use of allostery to identify inhibitors of calmodulin-induced activation of Bacillus anthracis edema factor

Laine

Gonçalves

Karst

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Allostery plays a key role in the regulation of the activity and function of many biomolecules. And although many ligands act through allostery, no systematic use is made of it in drug design strategies. Here we describe a procedure for identifying the regions of a protein that can be used to control its activity through allostery. This procedure is based on the construction of a plausible conformational path, which describes protein transition between known active and inactive conformations. The path is calculated by using a framework approach that steers and markedly improves the conjugate peak refinement method. The evolution of conformations along this path was used to identify a putative allosteric site that could regulate activation of Bacillus anthracis adenylyl cyclase toxin (EF) by calmodulin. Conformations of the allosteric site at different steps along the path from the inactive (free) to the active (bound to calmodulin) forms of EF were used to perform virtual screenings and propose candidate EF inhibitors. Several candidates then proved to inhibit calmodulin-induced activation in an in vitro assay. The most potent compound fully inhibited EF at a concentration of 10 μM. The compounds also inhibited the related adenylyl cyclase toxin from Bordetella pertussis (CyaA). The specific homology between the putative allosteric sites in both toxins supports that these pockets are the actual binding sites of the selected inhibitors.anthrax | transition path calculation | molecular dynamics | drug discovery | inhibition of protein-protein association

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Selective inhibition of anthrax edema factor by adefovir, a drug for chronic hepatitis B virus infection

Cited by 101 publications

References 41 publications

Anthrax Edema Toxin Cooperates with Lethal Toxin to Impair Cytokine Secretion during Infection of Dendritic Cells

Anthrax Edema Toxin Cooperates with Lethal Toxin to Impair Cytokine Secretion during Infection of Dendritic Cells

Molecular Analysis of the Interaction of Bordetella pertussis Adenylyl Cyclase with Fluorescent Nucleotides

Use of allostery to identify inhibitors of calmodulin-induced activation of Bacillus anthracis edema factor

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