Subcellular localization of acetoacetate coenzyme A transferase in rat hepatomas

Succinyl coenzyme A:acetoacetate coenzyme transferase (EC 2.8.3.5), an initiator of ketone body usage and absent in normal liver, has been shown to be located in mitochondria from Morris hepatoma 7288ctc using differential and density gradient centrifugation. Furthermore, tumor mitochondrial subfractionation revealed that this transferase is associated with the matrix-soluble proteins. Comparison of the amounts of total transferase activity in several other hepatomas with the amounts found in the corresponding isolated mitochondria suggests that the results with the 7288ctc tumor pertain generally. The mitochondrial localization of coenzyme A transferase indicates the probable use of ketone bodies as energy sources for the hepatomas.