Submitted on December 16, 2005
Revised on January 24, 2006
Accepted on January 25, 2006
Structures and biological activities of novel phosphatidylethanolamine lipids of porphyromonas gingivalis
Frank C. Nichols, Birgit Riep, JiYoung Mun, Martha D. Morton, Toshihisa Kawai, Floyd E. Dewhirst, and Michael B. Smith
Periodontology Dept., University of Connecticut School of Dental Medicine, Farmington, CT 06030
Corresponding Author: nichols{at}nso.uchc.edu
The Gram negative periodontal pathogen, Porphyromonas gingivalis, synthesizes several classes of novel phosphorylated complex lipids including the recently characterized phosphorylated dihydroceramides. These sphingolipids promote interleukin (IL)-1-mediated secretion of inflammatory mediators from fibroblasts, including prostaglandin E2 and 6-keto prostaglandin F2a, and alter gingival fibroblast morphology in culture. The present report demonstrates that one additional class of phosphorylated complex lipids of P. gingivalis promotes IL-1-mediated secretory responses and morphological changes in cultured fibroblasts. Structural characterization identified the new phospholipid class as 1, 2-diacyl phosphatidylethanolamine substituted predominantly with isobranched C15:0 and C13:0 fatty acids. The isobranched fatty acids rather than unbranched fatty acids, and the phosphoethanolamine head group were identified as the essential structural elements required for promotion of IL-1-mediated secretory responses. These structural components are also observed in specific phosphorylated sphingolipids of P. gingivalis, and likely contribute to the biological activity of these substances in addition to the phosphatidylethanolamine lipids described in this report.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
