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Live Imaging Assay for Assessing the Roles of Ca2+ and Sphingomyelinase in the Repair of Pore-forming Toxin Wounds
Published on: August 25, 2013
[Structure and function of sphingomyelinase].
1Department of Microbiology, Faculty of Pharmaceutical Science, Tokushima Bunri University, Tokushima, Japan. masa@ph.bunri-u.ac.jp
Yakugaku Zasshi : Journal of the Pharmaceutical Society of Japan
|October 3, 2009
Summary
Bacillus cereus sphingomyelinase (Bc-SMase) is a metalloenzyme and potential virulence factor. Its crystal structure reveals a conserved catalytic architecture, offering insights into mammalian nSMase function and membrane interactions.
Area of Science:
- Biochemistry
- Enzymology
- Structural Biology
Context:
- Bacillus cereus is a pathogen causing opportunistic infections.
- Sphingomyelinase (SMase) is a key virulence factor in B. cereus infections.
- Bc-SMase mimics endogenous mammalian neutral SMase (nSMase) activity.
Purpose:
- To elucidate the structural basis of Bc-SMase activity and metal ion activation.
- To provide a structural model for understanding mammalian nSMase function.
- To identify key structural features involved in substrate and membrane binding.
Summary:
- Bc-SMase is a Mg(2+)-containing metalloenzyme crucial for B. cereus virulence.
- Crystal structures reveal a conserved double metal ion catalytic site essential for activity.
- Activation is metal-dependent, with Co(2+) > Mn(2+) > Mg(2+).
- A beta-hairpin motif mediates binding to sphingomyelin and membranes.
Impact:
- Provides a structural framework for phosphohydrolases in the DNase I-like superfamily.
- Offers insights into the mechanism of sphingomyelin hydrolysis.
- Potential implications for understanding and targeting B. cereus pathogenesis.
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