Harrington John M, Chou Hui-Ting, Gutsmann Thomas, Gelhaus Christoph, Stahlberg Henning, Leippe Matthias, Armstrong Peter B
Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA.
FEBS Lett. 2009 Mar 18;583(6):1001-5. doi: 10.1016/j.febslet.2009.02.019. Epub 2009 Feb 21.
C-reactive protein (CRP) from the American horseshoe crab, Limulus polyphemus, exhibits complex membrane activities. Here, we describe the behavior of protein and lipid as CRP interacts with model liposomes and bacterial membranes. Limulus C-reactive protein (L-CRP) forms extended fibrilar structures that encapsulate liposomes in the presence of Ca(2+). We have observed structures consistent in size and shape with these fibers bound to the surface of Gram-negative bacteria. The membranes of Limulus CRP-treated bacteria exhibit significantly different mechano-elastic properties than those of untreated bacteria. In vitro, bilayer lipids undergo a rigidification and reorganization of small domains. We suggest that these interactions reflect the protein's role as a primary defense molecule, functioning in the entrapment and killing of potential pathogens.
