Studies on human serum high-density lipoproteins. V. Isolation and characterization of a cholesterol ester-rich lipoprotein after in vitro incubation.
Purified high-density lipoprotein (HDL), obtained by preparative ultracentrifugation at density 1.063-1.19 g/ml in the cold, were subfractionated by hydroxyl apatite column chromatography. Two of the obtained subfractions (subfractions II and III) turned turbid after incubation at 37 degrees C for 12 h. The turbid material was recovered in the supernatant of D 1.006 g/ml after centriguation at 30,000 g for 2 h. The lipoprotein fraction causing the turbidity was composed of 94% cholesterol ester and 2% apolipoprotein (by weight). On polyacrylamide gel electrophoresis the apolipoprotein moiety appeared as one polypeptide with the electrophoretic mobility of polypeptide A-I, revealed a blocked NH2-terminal amino acid, and had a total amino acid composition that differed from that of A-I and of the arginine-rich polypeptide.
D000596:Amino Acids / Q000032:analysis; D002784:Cholesterol / Q000031:analogs & derivatives*; D002788:Cholesterol Esters / Q000032:analysis*; D006801:Humans; D008075:Lipoproteins, HDL / Q000032:analysis* / Q000097:blood / Q000302:isolation & purification; D008297:Male
D000596:Amino Acids; D002788:Cholesterol Esters; D008075:Lipoproteins, HDL; D002784:Cholesterol