Send to

Choose Destination
Biochim Biophys Acta. 2008 Sep;1784(9):1271-6. doi: 10.1016/j.bbapap.2008.04.029. Epub 2008 May 10.

Interaction of the globular domain of human C1q with Salmonella typhimurium lipopolysaccharide.

Author information

Department of Biochemistry, Sofia University, St. Kliment Ohridski, 8 Dragan Tsankov St., Sofia 1164, Bulgaria.


Gram-negative bacteria can bind complement protein C1q in an antibody-independent manner and activate classical pathway via their lipopolysaccharides (LPS). Earlier studies have implicated the collagen-like region of human C1q in binding LPS. In recent years, a number of C1q target molecules, previously considered to interact with collagen-like region of C1q, have been shown to bind via the globular domain (gC1q). Here we report, using recombinant forms of the globular head regions of C1q A, B and C chains, that LPS derived from Salmonella typhimurium interact specifically with the B-chain of the gC1q domain in a calcium-dependent manner. LPS and IgG-binding sites on the gC1q domain appear to be overlapping and this interaction can be inhibited by a synthetic C1q inhibitor, suggesting common interacting mechanisms.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center