FIGURE 2.
TSG-6 interacts with high affinity with HC1, HC2, and HC3. A–F, representative figures of TSG-6 (analyte) interacting with immobilized rHC1 (A and B), rHC2 (C and D), and rHC3 (E and F) shown by surface plasmon resonance in HBS-T with 1 mm MgCl2 and 1 mm CaCl2 (A, C, and E) or in HBS-T with 10 mm EDTA (B, D, and F). Raw data and curve fits (with a 1:1 Langmuir model) are shown for TSG-6 concentrations of 6.25, 12.5, 25, 50, and 100 nm. KD values were determined from the mean of three experiments ± standard deviation. Stepwise changes in response at the end of sample injection are due to RI changes upon solution exchange, modeled by BiaEval 1:1 Langmuir model fitting. Other binding models tested did not improve the fit significantly. G, SDS-PAGE analysis of purified recombinant rHC1, rHC2, and rHC3 (each with an N-terminal His-tag (MAHHHHHHVGTGSNDDDDKSPDP)). 3 μg of rHC1, rHC2, and rHC3, respectively, were loaded per lane and run under reducing conditions, indicating that these preparations are >95% pure.