Membrane pore formation by pentraxin proteins from Limulus, the American horseshoe crab

作者:Harrington John M*; Chou Hui Ting; Gutsmann Thomas; Gelhaus Christoph; Stahlberg Henning; Leippe Matthias; Armstrong Peter B
来源:Biochemical Journal, 2008, 413: 305-313.
DOI:10.1042/BJ20071357

摘要

The pentraxins are a family of highly conserved plasma proteins of metazoans known to function in immune defence. The canonical members, C-reactive protein and serum amyloid P component, have been identified in arthropods and humans. Mammalian pentraxins are known to bind lipid bilayers, and a pentraxin representative from the American horseshoe crab, Limulus polyphemus, binds and permeabilizes mammalian erythrocytes. Both activities are Ca(2+)-dependent. Utilizing model liposomes and planar lipid bilayers, in the present study we have investigated the m ernbrane-active properties of the three pentraxin representatives from Limulus and show that all of the Limulus pentraxins permeabilize lipid bilayers. Mechanistically, Linudils C-reactive protein forms transmembrane pores in asymmetric planar lipid bilayers that mimic the outer membrane of Gram-negative bacteria and exhibits a Ca(2+)-independent form of membrane binding that may be sufficient for pore formation.

  • 出版日期2008-7-15