title: Further characterization of rat liver mitochondrial fractions. Lipid composition and synthesis, and protein profiles.
abstract: 1. Heavy and light mitochondrial fractions obtained by differential centrifugation were further characterized with respect to their lipid composition and synthesis and protein profiles, as seen by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 2. The light mitochondrial fraction was rich in total lipids, phospholipids and cholesterol. The cardiolipin content, however, was low. 3. Rates of [3H]glycerol incorporation into phospholipids of heavy mitochondria and microsomal fractions were almost identical. On the other hand, incorporation into the individual phospholipids in light mitochondria was about 4-6 times higher. Incorporation into cardiolipin of light mitochondria was about 10-fold higher than in the heavy mitochondria. 4. Analysis of protein profiles by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis showed that the pattern obtained for the light mitochondria was similar to that for heavy mitochondria. However, the light fraction was relatively poor in high-molecular-weight proteins and rich in low-molecular-weight proteins. The microsomal protein profile was altogether different. 5. The significance of these findings is discussed in relation to mitochondrial biogenesis.
mesh_terms: D000818:Animals; D002308:Cardiolipins / Q000096:biosynthesis; D002784:Cholesterol / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D050356:Lipid Metabolism; D008247:Lysosomes / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism*; D008970:Molecular Weight; D010455:Peptides / Q000378:metabolism; D010713:Phosphatidylcholines / Q000096:biosynthesis; D010714:Phosphatidylethanolamines / Q000096:biosynthesis; D010743:Phospholipids / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats
chemical_list: D002308:Cardiolipins; D010455:Peptides; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D011506:Proteins; D002784:Cholesterol; D005990:Glycerol