The compartmentation of the pathway for the synthesis of lipids from ketone bodies was examined in a cell free, post-mitochondrial supernatant fraction of malignant Morris hepatoma 7777 tissue. A fortified supernatant system effectively incorporated radioactive D(-)-3-hydroxybulyrate and acetoacetate into cholesterol and fatty acids, and both ketone bodies were directly converted to their CoA thioesters. Furthermore, a microsome-free (100,000 x g) cytosolic fraction was also able to acylate 3-hydroxybutyrate to 3-hydroxy-butyryl CoA. No previous identification of this enzyme activity has been described. These results which characterize a distinct extramitochondrial pathway for conversion of 3-hydroxybutyrate as well as acetoacetate into lipids also suggest the possibility of a previously undetected enzymatic activity for utilization of this ketone body.
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Aug 5 1996|