Discovery of sphingosine 1-O-methyltransferase in rat kidney and liver homogenates.
OBJECTIVE
To characterize sphingosine methyltransferase in rat tissues.


METHODS
By using S-adenosyl-L-(methyl-3H) methionine, enzymatic activity was measured in the rat liver and kidney homogenates.


RESULTS
The optimum pH and reaction time for the enzyme assay were pH 7.8 and 1 h. ZnCl2 inhibited the activity, but not MgCl2, CaCl2, CoCl2, or NiCl2. In the kidney homogenate, enzymatic activity was detectable in the cytosol and all membrane fractions from the plasma membrane and other organelles; however, in the liver homogenate, enzymatic activity was detectable in all membrane fractions, but not in the cytosol. We also tested the enzymatic activity with structurally-modified sphingosine derivatives.


CONCLUSIONS
We found sphingosine 1-O-methyltransferase activity in the rat liver and kidney homogenates.
Sacket
Santosh J
SJ
Laboratory of Pharmacology, College of Pharmacy (BK21 Project) and Longevity Life Science and Technology Institutes, Pusan National University, Busan 609-735, Korea.
Im
Dong-soon
DS
D000818:Animals; D002712:Chlorides / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000187:drug effects / Q000201:enzymology*; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008670:Metals / Q000494:pharmacology; D008780:Methyltransferases / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012436:S-Adenosylmethionine / Q000494:pharmacology; D013110:Sphingosine / Q000378:metabolism; D013379:Substrate Specificity; D014018:Tissue Distribution; D017967:Zinc Compounds / Q000494:pharmacology
D002712:Chlorides; D008670:Metals; D017967:Zinc Compounds; D012436:S-Adenosylmethionine; C016837:zinc chloride; D008780:Methyltransferases; C061802:sphingosine N-methyltransferase; D013110:Sphingosine