Hemolysis induced by Bacillus cereus sphingomyelinase.

Abstract

Bacillus cereus sphingomyelinase (Bc-SMase) induces hemolysis of sheep erythrocytes which contain large amounts of sphingomyelin. We investigated the mechanism of this hemolysis in comparison to that induced by Clostridium perfringens alpha-toxin. Pertussis toxin, a Gi-specific inhibitor, N-oleoylethernolamine, a ceramidase inhibitor, and dihydrosphingosine, a sphingosine kinase inhibitor, did not inhibit the hemolysis by Bc-SMase, but did inhibit that by alpha-toxin. Bc-SMase broadly bound to whole membranes, and alpha-toxin specifically bound to the detergent-resistant membrane fractions, lipid rafts. The level of ceramide production induced by Bc-SMase in sheep erythrocytes was 6- to 15-fold that induced by alpha-toxin, when the extent of the hemolysis by Bc-SMase was the same as that by the toxin. However, the level of ceramide production induced by Bc-SMase in SM-liposomes was equal to that triggered by the toxin, when the carboxyl fluorescein-release from liposomes induced by Bc-SMase was the same as that induced by alpha-toxin. Confocal laser microscopy showed that treatment of the cells with Bc-SMase resulted in the formation of ceramide-rich domains. A photobleaching analysis suggested that treatment of the cells with Bc-SMase leads to a reduction in membrane fluidity. These results show that Bc-SMase-induced hemolysis of sheep erythrocytes is related to the formation of interface between ceramide-rich domains and ceramide-poor domains through production of ceramide from SM.

• Authors: Masataka Oda, Masaya Takahashi, Takayuki Matsuno, Kana Uoo, Masahiro Nagahama, Jun Sakurai
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 1798 Issue 6 Pg. 1073-80 (Jun 2010) ISSN: 0006-3002 [Print] Netherlands
• PMID: 20214877 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Bacterial Toxins
• Calcium-Binding Proteins
• Ceramides
• Pertussis Toxin
• Type C Phospholipases
• Sphingomyelin Phosphodiesterase
• alpha toxin, Clostridium perfringens
• Sphingosine
• safingol

Topics

• Animals
• Bacillus cereus (enzymology, genetics)
• Bacterial Toxins (chemistry)
• Calcium-Binding Proteins (chemistry)
• Ceramides (chemistry)
• Erythrocyte Membrane (chemistry)
• Hemolysis
• Membrane Fluidity
• Membrane Microdomains (chemistry)
• Pertussis Toxin (chemistry)
• Sheep
• Sphingomyelin Phosphodiesterase (chemistry, genetics)
• Sphingosine (analogs & derivatives, chemistry)
• Type C Phospholipases (chemistry)