Prevention of in vitro low-density lipoprotein oxidation by an albumin-containing Lp A-I subfraction》.pdfVIP

~ , , . ,/ ! Biochi~ic~a etBiophysicaAEta ELSEVIER Biochimica et Biophysica Acta 1255 (1995) 31-38 Prevention of in vitro low-density lipoprotein oxidation by an albumin-containing Lp A-I subfraction Christelle Decossin, Anne Tailleux, Jean-Charles Fruchart, Catherine Fi~vet * Serlia et INSERM U325, Institut Pasteur, 1 rue du Professeur Calmette, F-59019 Lille C~dex, France Received 8 April 1994; revised 6 September 1994; accepted 8 November 1994 Abstract High-density lipoprotein (HDL) and two lipoprotein particles, those containing apo A-I and apo A-II (LpA-I:A-II) and those containing only apo A-I (LpA-I) were examined for their effect on Cu2+-catalyzed oxidation of human low-density lipoprotein (LDL). Lipoproteins and lipoprotein particles were prepared from plasma samples of five healthy subjects. LDL and HDL were purified by ultracentrifugation, LpA-I and LpA-I:A-II were isolated by an immunoaffinity chromatography procedure. The contaminating albumin often linked to the LpA-I affinity purified particles was eliminated by selected affinity immunosorption. The presence of HDL, LpA-I or LpA-I:A-II, at an apo A-I-containing lipoproteins/LDL ratio of 1, did not prevent LDL oxidation when assessed by oxidation kinetics, electrophoretic mobility, amounts of thiobarbituric acid-reactive products and fragmentation of apo B-100. On the other hand, when the albumin removing step was omitted, the s