Low density lipoprotein and very low density lipoprotein are selectively bound by aggregated C-reactive protein.

FC De Beer, AK Soutar, ML Baltz, IM Trayner… - The Journal of …, 1982 - rupress.org
FC De Beer, AK Soutar, ML Baltz, IM Trayner, A Feinstein, MB Pepys
The Journal of experimental medicine, 1982rupress.org
C-reactive protein (CRP), the classical acute-phase protein, can bind phospholipids by
virtue of its specific, calcium-dependent reactivity with phosphorylcholine residues.
However, analysis of acute-phase serum by gel filtration and by density gradient
ultracentrifugation showed that the CRP was in a free, uncomplexed form, despite the
coexistent presence of the various classes of serum lipoproteins, all of which contain
phospholipids. In contrast, when isolated CRP was aggregated by immobilization at a …
C-reactive protein (CRP), the classical acute-phase protein, can bind phospholipids by virtue of its specific, calcium-dependent reactivity with phosphorylcholine residues. However, analysis of acute-phase serum by gel filtration and by density gradient ultracentrifugation showed that the CRP was in a free, uncomplexed form, despite the coexistent presence of the various classes of serum lipoproteins, all of which contain phospholipids. In contrast, when isolated CRP was aggregated by immobilization at a sufficient density on a solid phase and then exposed to normal human serum, it selectively bound low density lipoprotein (LDL) and traces of very low density lipoprotein. The reaction was calcium dependent and reversible by free phosphorylcholine but not by heparin. LDL isolated from normal plasma was also bound by aggregated CRP. CRP reacts in vitro with a wide variety of different ligands both of extrinsic and of autogenous origin, e.g., microbial products and damaged cell membranes, respectively. If CRP aggregated in vivo by complexing with these ligands than acquires the capacity to selectively bind LDL, the phenomenon may have significant implications for the function of CRP and for the metabolism, clearance, and deposition of LDL.
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