AK15 (A) and its isomer AK15-6 (B) showed apparent affinity to mycobacterial cord factor (TDM). Interaction kinetics of peptides and TDM were determined by surface plasma resonance. Peptide was immobilized on a CM5 sensor chip as ligand, and TDM was diluted in a series of concentrations in HBS-N buffer. Responses (resonance units, RU) are recorded for the indicated concentrations of TDM (0, 5, 10, 20, and 40 nm).