Externalization of aminophospholipids in platelet liposome bilayers by supplementation with sphingomyelin.
Negatively charged phospholipids are mainly located on the inner leaflet of platelet liposomes. Using a specific reagent for amino groups, trinitrobenzenesulfanilic acid, we have shown that in large artificial vesicles prepared with total lipids from sheep platelets supplemented with increased amounts of exogenous sphingomyelin, an alteration in the amino-phospholipid topology occurs, with a progressive appearance of these lipid species -in particular phosphatidylserine- in the outer membrane bilayer.
Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Salamanca, Spain.
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Sánchez-Yagüe
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JA
Cabezas
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Llanillo
D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008051:Lipid Bilayers; D010713:Phosphatidylcholines / Q000097:blood; D010714:Phosphatidylethanolamines / Q000097:blood; D010718:Phosphatidylserines / Q000097:blood; D010743:Phospholipids / Q000097:blood*; D013109:Sphingomyelins / Q000097:blood / Q000494:pharmacology*
D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010718:Phosphatidylserines; D010743:Phospholipids; D013109:Sphingomyelins