Table 1.
Rate constants for association (kon) and dissociation (koff) of the complex between IL-4 variants and IL4-BP immobilized at a biosensor matrix
IL-4 variant | kon × 10−6 M−1·s−1 | koff × 103 s−1 | IL-4 variant | kon × 10−6 M−1·s−1 | koff × 103 s−1 |
---|---|---|---|---|---|
IL4 | 13 | 2.1 | |||
I5A | 12 | 14 | I5R | 14 | 8.7 |
T6A | 14 | 1.9 | T6D | 8.8 | 15 |
Q8A | 16 | 2.5 | Q8R | 11 | 1.9 |
E9Q | 8.7 | 270 | E9K | ND | ND |
E9A | ND | ND | |||
I11A | 11 | 2 | |||
K12S | 12 | 1.9 | K12E | 7.3 | 1.5 |
T13A | 8.4 | 7.1 | T13D | 7.6 | 0.85 |
N15A | 15 | 2.3 | N15D | 12 | 1.7 |
S16A | 16 | 1.9 | S16D | 11 | 1.5 |
E19A | 18 | 1.7 | E19R | 12 | 1.6 |
R53Q | 11 | 7.3 | |||
K77A | 10 | 2.1 | K77E | 4.4 | 2 |
Q78A | 11 | 2.2 | Q78E | 11 | 2.7 |
R81A | 7.7 | 2.8 | R81E | 3.2 | 6.1 |
F82A | 15 | 2.1 | F82D | 12 | 0.73 |
K84A | 10 | 2.9 | K84D | 2.4 | 9.3 |
R85A | 8.1 | 2.7 | R85E | 3.6 | 4.6 |
R88Q | 7.3 | 140 | R88D | ND | ND |
R88A | 8.3 | 760 | |||
N89A | 12 | 27 | N89R | ND | ND |
W91A | 11 | 6.1 | W91D | 5.8 | 8.5 |
The association and dissociation of IL-4 variants and IL4-BP immobilized at a biosensor matrix was measured in real time by means of a BIA2000 system. The rate constants represent mean values of 12–24 independent measurements performed with at least three different analyte concentrations. The mean standard deviation was 15% for the kon and 25% for the koff values. ND, not determined (only unspecific binding was found).