Binding of anti-human-interleukin-6 monoclonal antibodies to synthetic peptides of human interleukin-6 studied using surface plasmon resonance.
Biosensor technology employing surface plasmon resonance (SPR) detection provides a highly-sensitive (sub ng), non-extrinsic labelling approach for monitoring protein interactions in real-time. We have used this approach to map the binding sites on human interleukin-6 (hIL-6) for a series of anti-hIL-6 monoclonal antibodies (mAbs). Epitopes were localised by monitoring the ability of ten synthetic peptides, spanning the sequence of hIL-6, to inhibit the binding of anti-hIL-6 mAbs to immobilised hIL-6. Peptide P8 (Pro139-Gln153) inhibited binding of anti-IL-6-mAbs 1, 2 and 7. To increase the sensitivity of detection of antibody-synthetic peptide interactions, a procedure was developed for immobilising the synthetic peptides directly to the sensor surface of the SPR instrument. From this study, association equilibrium constants of 2.1 x 10(6)M-1 and 3.6 x 10(4)M-1 were calculated for the mAb7-immobilised P8 and mAb7-free P8 interactions, respectively.
Ward
L D
LD
Joint Protein Structure Laboratory, Ludwig Institute for Cancer Research, Melbourne Branch, Australia.
Shi
P T
PT
Simpson
R J
RJ
D000911:Antibodies, Monoclonal / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015850:Interleukin-6 / Q000138:chemical synthesis / Q000276:immunology*; D008722:Methods
D000911:Antibodies, Monoclonal; D015850:Interleukin-6