Human adiponectin binds to bacterial lipopolysaccharide.
Adiponectin has anti-inflammatory and anti-atherogenic properties in addition to its acknowledged roles in insulin sensitivity and energy homeostasis. These properties include the suppression of lipopolysaccharide [LPS]-mediated inflammatory events. We demonstrated that both recombinant and native adiponectin directly bind LPS derived from three different bacteria. The interaction occurred at pH 5.0-6.0 and was inhibited by the presence of Ca(2+) and Mg(2+), but enhanced by the sequestration of these cations. Maximal binding occurred at pH 6.0 in the presence of ethylenediaminetetraacetic acid. Lipid A and C1q were not inhibitory, although LPS, heparin, zymosan, and individual sugars all inhibited the reaction. Periodate-mediated deglycosylation of adiponectin, and reduction and alkylation also inhibited binding. Since adiponectin infiltrates into [relatively] acidic sites of inflammation, it may act as a scavenging anti-inflammatory agent in atherosclerosis and vascular damage where LPS [and other pro-inflammatory molecules] are present.
Peake
Philip W
PW
Division of Medicine, Prince of Wales Hospital, Randwick, Australia. P.Peake@unsw.edu.au
Shen
Yvonne
Y
Campbell
Lesley V
LV
Charlesworth
John A
JA
D052242:Adiponectin / Q000737:chemistry; D001665:Binding Sites; D004926:Escherichia coli / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008070:Lipopolysaccharides / Q000737:chemistry*; D011485:Protein Binding
C499918:ADIPOQ protein, human; D052242:Adiponectin; D008070:Lipopolysaccharides