title: Lipid composition of purified transverse tubule membranes isolated from amphibian skeletal muscle.
abstract: The level and proportion of lipids and their fatty acid composition were analyzed in highly purified transverse tubule membranes of amphibian skeletal muscle. Tubule membranes show (a) a higher content of lipids, (b) a higher phospholipid/cholesterol ratio and (c) a different phospholipid composition from other subcellular fractions, such as the light and heavy membranes from sarcoplasmic reticulum, which are similar in lipid profile. Transverse tubule membranes are characterized by a high percentage of phosphatidylserine and sphingomyelin and a low proportion of phosphatidylcholine compared with the other membranes. All three show a high proportion of ethanolamine plasmalogens (50% of the total ethanolamine glycerophospholipid). Transverse tubule membrane lipids contain a high proportion of 20- and 22-carbon polyunsaturated fatty acids, predominantly 20:4, 20:5, 22:5 and 22:6. Arachidonate predominates in phosphatidylinositol, eicosapentaenoate and docosahexaenoate in ethanolamine and serine glycerophospholipids.
mesh_terms: D000818:Animals; D001001:Anura; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000032:analysis; D002784:Cholesterol / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D007425:Intracellular Membranes / Q000032:analysis*; D008563:Membrane Lipids / Q000032:analysis*; D009132:Muscles / Q000032:analysis* / Q000648:ultrastructure; D010718:Phosphatidylserines / Q000032:analysis; D010743:Phospholipids / Q000032:analysis; D010955:Plasmalogens / Q000032:analysis; D013109:Sphingomyelins / Q000032:analysis
chemical_list: D001095:Arachidonic Acids; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008563:Membrane Lipids; D010718:Phosphatidylserines; D010743:Phospholipids; D010955:Plasmalogens; D013109:Sphingomyelins; C020791:phosphatidal ethanolamines; D016718:Arachidonic Acid; D002784:Cholesterol