TABLE 4.
Protein | Ligand | Kd (μM)a | Kd (μM)b | kon (104 s−1 M−1)b | koff (s−1)b |
---|---|---|---|---|---|
rDbpA | Decorin | 0.32 ± 0.05 | 0.29 ± 0.06 | 35.05 ± 6.15 | 0.099 ± 0.003 |
Dermatan sulfate | 0.47 ± 0.05 | 0.46 ± 0.08 | 5.21 ± 0.16 | 0.024 ± 0.004 | |
rDbpAK51A | Decorin | 0.74 ± 0.05 | 0.79 ± 0.03 | 12.6 ± 1.70 | 0.099 ± 0.018 |
Dermatan sulfate | 1.45 ± 0.37 | 1.17 ± 0.28 | 2.57 ± 0.32 | 0.030 ± 0.003 | |
rDbpAK82A | Decorin | NBc | NB | NB | NB |
Dermatan sulfate | NB | NB | NB | NB | |
rDbpAK124A | Decorin | 0.28 ± 0.04 | 0.28 ± 0.14 | 29.25 ± 7.50 | 0.084 ± 0.01 |
Dermatan sulfate | 0.47 ± 0.02 | 0.54 ± 0.11 | 5.92 ± 0.53 | 0.032 ± 0.009 | |
rDbpAK163A | Decorin | NB | NB | NB | NB |
Dermatan sulfate | NB | NB | NB | NB | |
rDbpAK170A | Decorin | NB | NB | NB | NB |
Dermatan sulfate | NB | NB | NB | NB | |
rDbpAK177A | Decorin | 0.30 ± 0.03 | 0.20 ± 0.06 | 35.70 ± 1.10 | 0.071 ± 0.004 |
Dermatan sulfate | 0.48 ± 0.04 | 0.53 ± 0.09 | 3.34 ± 0.18 | 0.018 ± 0.004 |
Calculated from the ELISA experiments shown in Fig. S1 in the supplemental material. The Kd values are the means ± standard deviations (SD) from three independent experiments.
Calculated from the SPR experiments shown in Fig. S2 in the supplemental material. kon, association rate constant; koff, dissociation rate constant. The Kd, kon, and koff values are the means ± SD from three independent experiments.
NB, no binding. rDbpAK82A, rDbpAK163A, and rDbpAK170A bound decorin and dermatan sulfate so poorly that curve-fitting software could not accurately calculate the Kd, kon, and koff values. Since these values were not available, it was not possible to do a statistical analysis of decorin or dermatan sulfate binding between these mutants and WT DbpA.