Article
Physiological calcium concentrations regulate calmodulin binding and catalysis of adenylyl cyclase exotoxins.
The EMBO journal - 16 Dec 2002
Shen Yuequan, Lee Young-Sam, Soelaiman Sandriyana, Bergson Pamela, Lu Dan, Chen Alice, Beckingham Kathy, Grabarek Zenon, Mrksich Milan, Tang Wei-Jen
Abstract excerpt
Edema factor (EF) and CyaA are calmodulin (CaM)-activated adenylyl cyclase exotoxins involved in the pathogenesis of anthrax and whooping cough, respectively. Using spectroscopic, enzyme kinetic and surface plasmon resonance spectroscopy analyses, we show that low Ca(2+) concentrations increase the affinity of CaM for EF and CyaA causing their activation, but higher Ca(2+) concentrations directly inhibit...
Topics
- Adenylyl Cyclases
- Binding Sites
- Calcium
- Calmodulin
- Catalysis
- Dose-Response Relationship, Drug
- Enzyme Activation
- Escherichia coli
- Exotoxins
- Magnesium
- Models, Molecular
- Mutation
- Plasmids