Pentraxins family of proteins acquired the name from their ability to form pentameric (or decameric) structures formed by non-covalent interactions.
C-reactive protein (CRP or PTX1; mature chain 206 aa; chromosome 1q21-23) nonglycosylated, ~24kD monomer and ~118kD pentamer) is a ubiquitous protein found in both vertebrates and invertebrates.
Originally CRP was defined as a substance, observed in the plasma of patients with acute infections, that reacted with the C polysaccharide of the pneumococcus.
It is one of the plasma proteins that are called acute phase reactants because of a pronounced rise in concentration after tissue injury or inflammation; in the case of CRP the rise may be 1000-fold or more.
CRP is composed of 5 identical, 21,500-molecular weight subunits.
It is detectable on the surface of about 4% of normal peripheral blood lymphocytes.
Acute phase reactant CRP is produced in the liver; those cells produce CRP detectable on lymphocytes.