%0 Journal Article %T Discovery of sphingosine 1- O -methyltransferase in rat kidney and liver homogenates %A Sacket Santosh J %A Im Dong-soon %J Acta Pharmacologica Sinica %D 2016 %B 2016 %9 %! Discovery of sphingosine 1- O -methyltransferase in rat kidney and liver homogenates %K %X Aim: To characterize sphingosine methyltransferase in rat tissues. Methods: By using S-adenosyl-L-(methyl- 3 H) 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 MgCl 2 , CaCl 2 , CoCl 2 , or NiCl 2 . 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. Conclusion: We found sphingosine 1- O -methyltransferase activity in the rat liver and kidney homogenates. %U http://www.chinaphar.com/article/view/6333 %V 29 %N 10 %P 1227-1232 %@ 1745-7254