A 70-kDa apolipoprotein designated ApoJ is a marker for subclasses of human plasma high density lipoproteins.
A new apolipoprotein, termed apolipoprotein J (apoJ), was purified from human plasma by immunoaffinity chromatography. ApoJ is a glycoprotein consisting of disulfide-linked subunits of 34-36 and 36-39 kDa. Each subunit is glycosylated and has a pI range of 4.9-5.4. ApoJ exists in the plasma associated with high density lipoproteins (HDL) and specifically with subclasses of HDL which also contain apoAI and cholesteryl ester transfer protein activity. Immunoaffinity purified apoJ-HDL subclasses have apparent molecular masses of 80, 160, 240, 340, and 520 kDa, as determined by gradient gel electrophoresis. By negative staining electron microscopy, apoJ-HDL range in diameter from 5 to 16 nm. Fractionation of plasma by vertical gradient density centrifugation revealed apoJ-HDL in HDL2 (d 1.063-1.125 g/ml) with the majority overlapping HDL3 (d 1.125-1.21 g/ml) and very high density lipoprotein (d 1.21-1.25 g/ml). The bimodal density distribution of apoJ-HDL suggests that these subclasses have a unique metabolic relationship and may play a role in the transport of cholesterol from peripheral tissues to the liver.
de Silva
H V
HV
Department of Pharmacology, University of Cincinnati, Ohio 45267.
Stuart
W D
WD
Duvic
C R
CR
Wetterau
J R
JR
Ray
M J
MJ
Ferguson
D G
DG
Albers
H W
HW
Smith
W R
WR
Harmony
J A
JA
D000911:Antibodies, Monoclonal; D001053:Apolipoproteins / Q000097:blood* / Q000302:isolation & purification; D015415:Biomarkers / Q000097:blood*; D002352:Carrier Proteins / Q000097:blood; D053480:Cholesterol Ester Transfer Proteins; D002846:Chromatography, Affinity; D051152:Clusterin; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins; D006801:Humans; D015151:Immunoblotting; D008075:Lipoproteins, HDL / Q000097:blood* / Q000145:classification / Q000302:isolation & purification / Q000648:ultrastructure; D008077:Lipoproteins, LDL / Q000097:blood; D008854:Microscopy, Electron; D018832:Molecular Chaperones; D008970:Molecular Weight
D000911:Antibodies, Monoclonal; D001053:Apolipoproteins; D015415:Biomarkers; C506642:CETP protein, human; C495242:CLU protein, human; D002352:Carrier Proteins; D053480:Cholesterol Ester Transfer Proteins; D051152:Clusterin; D006023:Glycoproteins; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D018832:Molecular Chaperones