A new sensitive assay for the calcium-dependent binding of C-reactive protein to phosphorylcholine.
A new sensitive assay for the calcium-dependent binding of rabbit C-reactive protein to phosphorylcholine has been developed. The assay involves coating the wells of polyvinylchloride microtiter plates with a bovine serum albumin-phosphorylcholine conjugate followed by the addition of C-reactive protein. The quantity of C-reactive protein is determined by indirect enzyme-linked immunoadsorbent assay using first, affinity purified goat anti-C-reactive protein immunoglobulin followed by a commercial rabbit anti-goat immunoglobulin-alkaline phosphatase conjugate. The binding of rabbit C-reactive protein to the bovine serum albumin-phosphorylcholine conjugate is completely inhibited by free phosphorylcholine, by pneumococcal C-polysaccharide and by calcium chelators but not by high concentrations of neutral, cationic or zwitterionic detergents. The assay is sensitive to 2 ng C-reactive protein.
D000818:Animals; D001667:Binding, Competitive; D002097:C-Reactive Protein / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D002794:Choline / Q000031:analogs & derivatives*; D003902:Detergents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007163:Immunosorbent Techniques; D010767:Phosphorylcholine / Q000378:metabolism* / Q000494:pharmacology; D011135:Polysaccharides, Bacterial / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D011732:Pyridoxal Phosphate / Q000494:pharmacology; D011817:Rabbits; D012710:Serum Albumin, Bovine / Q000378:metabolism
D002614:Chelating Agents; D003902:Detergents; D011135:Polysaccharides, Bacterial; C027158:polysaccharide C-substance (Streptococcus); D010767:Phosphorylcholine; D012710:Serum Albumin, Bovine; D011732:Pyridoxal Phosphate; D002097:C-Reactive Protein; D002794:Choline; D002118:Calcium