TY - JOUR
T1 - Interaction of the globular domain of human C1q with Salmonella typhimurium lipopolysaccharide
AU - Roumenina, Lubka T.
AU - Popov, Krustyo T.
AU - Bureeva, Svetlana V.
AU - Kojouharova, Mihaela
AU - Gadjeva, Mihaela
AU - Rabheru, Shweta
AU - Thakrar, Roshni
AU - Kaplun, Alexander
AU - Kishore, Uday
PY - 2008/9
Y1 - 2008/9
N2 - 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.
AB - 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.
KW - C1q
KW - Ca
KW - IgG
KW - Recognition
KW - Salmonella lipopolysaccharide
UR - http://www.scopus.com/inward/record.url?scp=53149094009&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=53149094009&partnerID=8YFLogxK
U2 - 10.1016/j.bbapap.2008.04.029
DO - 10.1016/j.bbapap.2008.04.029
M3 - Article
C2 - 18513495
AN - SCOPUS:53149094009
SN - 1570-9639
VL - 1784
SP - 1271
EP - 1276
JO - Biochimica et Biophysica Acta - Proteins and Proteomics
JF - Biochimica et Biophysica Acta - Proteins and Proteomics
IS - 9
ER -