title: Membrane activity of a C-reactive protein.
abstract: 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.
authors.affiliation: Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA. jmharrin@uga.edu
authors.forename: John M
authors.initials: JM
authors.lastname: Harrington
authors.forename: Hui-Ting
authors.initials: HT
authors.lastname: Chou
authors.forename: Thomas
authors.initials: T
authors.lastname: Gutsmann
authors.forename: Christoph
authors.initials: C
authors.lastname: Gelhaus
authors.forename: Henning
authors.initials: H
authors.lastname: Stahlberg
authors.forename: Matthias
authors.initials: M
authors.lastname: Leippe
authors.forename: Peter B
authors.initials: PB
authors.lastname: Armstrong
mesh_terms: D000371:Agglutination / Q000187:drug effects; D000372:Agglutination Tests; D000818:Animals; D001419:Bacteria / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism*; D003198:Computer Simulation; D006737:Horseshoe Crabs; D008051:Lipid Bilayers / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects
chemical_list: D008051:Lipid Bilayers; D008081:Liposomes; D008563:Membrane Lipids; D002097:C-Reactive Protein; D002118:Calcium