Phospholipid asymmetry in renal brush-border membranes.
The topological distribution of phospholipids between the inside and the outside of rabbit kidney brush-border membranes has been investigated by incubating membrane vesicles with sphingomyelinase, phospholipases A2 from bee venom and hog pancreas, phospholipases C and D, and trinitrobenzene sulfonate. Orientation and integrity of vesicles upon phospholipase treatment was determined by using two monoclonal antibodies recognizing an extracytoplasmic and a cytoplasmic domain, respectively, of the neutral endopeptidase (EC 3.4.24.11). It is shown that the transbilayer distribution of phospholipids is highly asymmetrical in kidney brush-border membranes: sphingomyelin accounted for 75% of the phospholipids present in the external leaflet, whereas phosphatidylethanolamine and phosphatidylserine plus phosphatidylinositol were found to comprise the majority of the inner layer of the membrane.
Venien
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INSERM U.251, Département de Physiologie, Faculté de Medecine Xavier-Bichat, Paris, France.
Le Grimellec
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C
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000648:ultrastructure; D007672:Kidney Cortex / Q000648:ultrastructure*; D008563:Membrane Lipids / Q000502:physiology*; D008666:Metalloendopeptidases / Q000276:immunology / Q000378:metabolism; D008871:Microvilli / Q000648:ultrastructure; D015260:Neprilysin; D010740:Phospholipases / Q000378:metabolism; D010743:Phospholipids / Q000502:physiology*; D011817:Rabbits; D013108:Sphingomyelin Phosphodiesterase / Q000502:physiology; D013552:Swine; D014302:Trinitrobenzenesulfonic Acid / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D008563:Membrane Lipids; D010743:Phospholipids; D014302:Trinitrobenzenesulfonic Acid; D010740:Phospholipases; D013108:Sphingomyelin Phosphodiesterase; D008666:Metalloendopeptidases; D015260:Neprilysin