Kinetics of binding of LPS to recombinant CD14, TLR4, and MD-2 proteins.
TLR4 together with CD14 and MD-2 forms a pattern recognition receptor that plays an initiating role in the innate immune response to Gram-negative bacteria. Here, we employed the surface plasmon resonance technique to investigate the kinetics of binding of LPS to recombinant CD14, MD-2 and TLR4 proteins produced in insect cells. The dissociation constants (KD) of LPS for immobilized CD14 and MD-2 were 8.7 microM, and 2.3 microM, respectively. The association rate constant (Kon) of LPS for MD-2 was 5.61 x 10(3) M-1S-1, and the dissociation rate constant (Koff) was 1.28 10 2 S 1, revealing slow association and fast dissociation with an affinity constant KD of 2.33 x 10-6 M at 25 degreesC. These affinities are consistent with the current view that CD14 conveys LPS to the TLR4/MD-2 complex.
Shin
Han Jae
HJ
Department of Biochemistry, Chungnam National University, Daejeon 305-764, Korea.
Lee
Hayyoung
H
Park
Jong Dae
JD
Hyun
Hak Chul
HC
Sohn
Hyung Ok
HO
Lee
Dong Wook
DW
Kim
Young Sang
YS
D000818:Animals; D007700:Kinetics; D018950:Lipopolysaccharide Receptors / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry*; D051218:Lymphocyte Antigen 96 / Q000737:chemistry*; D051379:Mice; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry; D012995:Solubility; D051197:Toll-Like Receptor 4 / Q000737:chemistry*
D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; C411728:Ly96 protein, mouse; D051218:Lymphocyte Antigen 96; D011994:Recombinant Proteins; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4