Activation of magnesium-dependent, neutral sphingomyelinase by phosphatidylserine.

Abstract

The plasma membrane isolated from rat ascites hepatoma, AH 7974 cells was treated with 1% Triton X-100, which resulted in a more than 80% reduction in the phospholipid content of the plasma membrane. The delipidized plasma membrane showed only 18% of the activity of the magnesium-dependent, neutral sphingomyelinase in the untreated plasma membrane. On the addition of acidic phospholipids, especially phosphatidylserine, however, the enzyme activity in the delipidized membrane was markedly restored up to 77% of that in the untreated membrane. It was suggested that, considering the phospholipid composition of the AH 7974 plasma membrane (Koizumi, K. et al. (1977) Cell Struct. Func. 2, 145-153), phosphatidylserine may be a natural activator of neutral sphingomyelinase.

• Authors: K Tamiya-Koizumi, K Kojima
• Journal: Journal of biochemistry (J Biochem) Vol. 99 Issue 6 Pg. 1803-6 (Jun 1986) ISSN: 0021-924X [Print] England
• PMID: 3017927 (Publication Type: Journal Article)

Chemical References

• Phosphatidylserines
• Phospholipids
• Phosphoric Diester Hydrolases
• Sphingomyelin Phosphodiesterase
• Magnesium

Topics

• Animals
• Cell Membrane (enzymology)
• Enzyme Activation (drug effects)
• Liver Neoplasms, Experimental (enzymology)
• Magnesium (pharmacology)
• Phosphatidylserines (pharmacology)
• Phospholipids (pharmacology)
• Phosphoric Diester Hydrolases (metabolism)
• Rats
• Sphingomyelin Phosphodiesterase (metabolism)