Taha, Hesham M. and Schmidt, Jennifer and Goettle, Martin and Suryanarayana, Srividya and Shen, Yuequan and Tang, Wei-Jen and Gille, Andreas and Geduhn, Jens and Koenig, Burkhard and Dove, Stefan and Seifert, Roland (2009) Molecular Analysis of the Interaction of Anthrax Adenylyl Cyclase Toxin, Edema Factor, with 2 '(3 ')-O-(N-(methyl)anthraniloyl)-Substituted Purine and Pyrimidine Nucleotides. MOLECULAR PHARMACOLOGY, 75 (3). pp. 693-703. ISSN 0026-895X, 1521-0111
Full text not available from this repository. (Request a copy)Abstract
Bacillus anthracis causes anthrax disease and exerts its deleterious effects by the release of three exotoxins: lethal factor, protective antigen, and edema factor (EF), a highly active calmodulin-dependent adenylyl cyclase (AC). However, conventional antibiotic treatment is ineffective against either toxemia or antibiotic-resistant strains. Thus, more effective drugs for anthrax treatment are needed. Previous studies from our laboratory showed that mammalian membranous AC (mAC) exhibits broad specificity for purine and pyrimidine nucleotides (Mol Pharmacol 70:878-886, 2006). Here, we investigated structural requirements for EF inhibition by natural purine and pyrimidine nucleotides and nucleotides modified with N-methylanthraniloyl (MANT)- or anthraniloyl groups at the 2'(3')-O ribosyl position. MANT-CTP was the most potent EF inhibitor (K-i, 100 nM) among 16 compounds studied. MANT-nucleotides inhibited EF competitively. Activation of EF by calmodulin resulted in effective fluorescence resonance energy transfer (FRET) from tryptophan and tyrosine residues located in the vicinity of the catalytic site to MANT-ATP, but FRET to MANT-CTP was only small. Mutagenesis studies revealed that Phe586 is crucial for FRET to MANT-ATP and MANT-CTP and that the mutations N583Q, K353A, and K353R differentially alter the inhibitory potencies of MANT-ATP and MANT-CTP. Docking approaches relying on crystal structures of EF indicate similar binding modes of the MANT nucleotides with subtle differences in the region of the nucleobases. In conclusion, like mAC, EF accommodates both purine and pyrimidine nucleotides. The unique preference of EF for the base cytosine offers an excellent starting point for the development of potent and selective EF inhibitors.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | CALMODULIN-BINDING; STRUCTURAL BASIS; FLUORESCENT; INHIBITION; ANALOGS; PROTEINS; SITE; |
| Subjects: | 500 Science > 540 Chemistry & allied sciences 600 Technology > 615 Pharmacy |
| Divisions: | Chemistry and Pharmacy > Institute of Pharmacy > Alumni or Retired Professors > Pharmaceutical/Medicinal Chemistry II (Prof. Buschauer) Chemistry and Pharmacy > Institute of Pharmacy > Pharmacology and Toxicology (Prof. Schlossmann, formerly Prof. Seifert) Chemistry and Pharmacy > Institut für Organische Chemie > Lehrstuhl Prof. Dr. Burkhard König |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 05 Oct 2020 06:31 |
| Last Modified: | 05 Oct 2020 06:31 |
| URI: | https://pred.uni-regensburg.de/id/eprint/29418 |
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