Displays several functions associated with host defense: it promotes agglutination, bacterial capsular swelling, phagocytosis and complement fixation through its calcium-dependent binding to phosphorylcholine. Can interact with DNA and histones and may scavenge nuclear material released from damaged circulating cells. Binds 2 calcium ions per subunit. Homopentamer. Pentraxin (or pentaxin) have a discoid arrangement of 5 non-covalently bound subunits. Interacts with FCN1; may regulate monocyte activation by FCN1. Found in plasma. The concentration of CRP in plasma increases greatly during acute phase response to tissue injury, infection or other inflammatory stimuli. It is induced by IL1/interleukin-1 and IL6/interleukin-6. This protein owes its name to its ability precipitate pneumococcal C-polysaccharide in the presence of calcium. Belongs to the pentraxin family. C-reactive protein entry No more Christmas pudding? - Issue 30 of January 2003