Heat shock protein 60 is a high-affinity high-density lipoprotein binding protein.
A new 55-kDa HDL/apolipoprotein binding protein was demonstrated in plasma membrane preparations of the human cell lines and primary cultured hepatocytes. Analysis of specific binding by ligand immunoblots of HDL, apoA-I, and apoA-II to a partially purified 55-kDa PA-I plasma membrane preparation demonstrated a K(d,HDL) = 50 nM (10 microg/ml), K(d,apoA-II) = 20 nM (0.4 microg/ml), and K(d, apoA-I) = 330 nM (10 microg/ml). Following preparative SDS-PAGE electrophoresis of a plasma membrane preparation isolated from human PA-I cells, fractions with apoA-II binding activity were collected, concentrated, and subjected to two-dimensional electrophoresis. Internal microprotein sequencing of the 55-kDa protein band revealed the binding protein as being heat shock protein 60 (hsp60). The hsp60 monoclonal antibody LK-1 blocked apoA-II binding to the 55-kDa HBP preparation. In summary, these results provide a potential mechanism to explain the known association between immunity developed against hsp60 and the development of atherosclerosis.
Bocharov
A V
AV
Center for Biologics and Evaluation and Research, Division of Cellular and Gene Therapies, Food and Drug Administration, 8800 Rockville Pike, Bethesda, Maryland 20892, USA.
Vishnyakova
T G
TG
Baranova
I N
IN
Remaley
A T
AT
Patterson
A P
AP
Eggerman
T L
TL
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D016632:Apolipoprotein A-I / Q000378:metabolism; D016633:Apolipoprotein A-II / Q000378:metabolism; D001161:Arteriosclerosis / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry; D018834:Chaperonin 60 / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D015151:Immunoblotting; D008024:Ligands; D008075:Lipoproteins, HDL / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011485:Protein Binding / Q000187:drug effects; D020539:Sequence Analysis, Protein; D013816:Thermodynamics
D000911:Antibodies, Monoclonal; D016632:Apolipoprotein A-I; D016633:Apolipoprotein A-II; D018834:Chaperonin 60; D008024:Ligands; D008075:Lipoproteins, HDL; D008565:Membrane Proteins