A newly discovered apolipoprotein B-containing high-density lipoprotein produced by human hepatoma cells.
Apolipoprotein B-containing high-density lipoprotein was detected in the high-density lipoprotein fraction of the concentrated conditioned medium of human hepatoma HuH-7 cells (Apo-B-containing HDLHuH-7). Electrophoretically, the Apo-B-containing HDLHuH-7 migrated more slowly and broadly than beta-lipoprotein on agarose gel. The Apo-B-containing HDLHuH-7 was not precipitated by heparin-Mn2+ treatment. High-performance gel filtration chromatography indicated that the peak of Apo-B-containing HDLHuH-7 was eluted faster than that of plasma LDL and electron microscopic analysis demonstrated that the particles of Apo-B-containing HDLHuH-7 ranged from 140 A to about 450 A, indicating the heterogeneity of Apo-B-containing HDLHuH-7. The protein/lipid ratio of HDLHuH-7 (1.35) is higher than that of plasma HDL3 (1.2). The lipids of HDLHuH-7 are composed of phospholipids (170 micrograms/mg protein), free cholesterol (410 micrograms/mg protein), cholesterol ester (20 micrograms/mg protein) and triacylglycerols (140 micrograms/mg protein). The results described above indicated that Apo-B-containing HDLHuH-7 was a novel lipoprotein discovered for the first time.
Yamamoto
T
T
Third Department of Internal Medicine, Hyogo College of Medicine, Japan.
Takahashi
S
S
Moriwaki
Y
Y
Hada
T
T
Higashino
K
K
D001055:Apolipoproteins B / Q000096:biosynthesis* / Q000302:isolation & purification; D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D006801:Humans; D005779:Immunodiffusion; D008075:Lipoproteins, HDL / Q000096:biosynthesis* / Q000302:isolation & purification; D008113:Liver Neoplasms; D008854:Microscopy, Electron
D001055:Apolipoproteins B; D008075:Lipoproteins, HDL