A Novel Oxidized Low Density
Lipoprotein-binding Protein in Macrophage
ZHOU Chun-Lei
( Department of Cardiology,454 Hospital of the Chinese People’s Liberation
Army,Nanjing 210001 )
CHEN Qi*,WEI En-Hui,CHEN Xiu-Ying,WANG Nan and FAN Le-Ming
(Atherosclerosis Research Center,Nanjing Medical University,Nanjing
210029,China)
Abstract Scavenger receptor A(SR-A)on
the mouse peritoneal macrophages(MPM) mediates the endocytic uptake of oxidized
low density lipoproteins(ox-LDL). However,using ligand blotting and
immunoblotting,a novel macrophage membrane protein binding to ox-LDL with
estimated molecular mass of 92 kD was found. This membrane protein could not
bind to ac-LDL. Its binding to ligands was not affected by reducing reagents
either. Preincubation with medium containing neuraminidase dramatically
decreased binding of the 92 kD membrane protein to ox-LDL. Excess amounts of
ox-LDL could completely block the binding of [125I]ox-LDL to 92 kD
membrane protein,but polyI,dextran sulfate and fucoidin showed partial
competitive inhibition effects to the binding. These results suggest that the
novel 92 kD membrane protein plays important role in the MPM uptake of ox-LDL.
Key Words Membrane protein；oxidized low density
lipoprotein；macrophages
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