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Table 1 BIAcore analysis of IL-4, IL-13 and variants

From: A modular interface of IL-4 allows for scalable affinity without affecting specificity for the IL-4 receptor

IL-4 variant k on × 10-7 [s-1 M-1] k off × 103 [s-1] app. K D [nM] relative K D (K D(mut)/K D(IL-4))
IL4 1.32 ± 0.27 1.26 ± 0.16 0.10 ± 0.02 1.0
T13D 1.27 ± 0.19 0.46 ± 0.16 0.04 ± 0.02 0.4
F82D 1.61 ± 0.15 0.46 ± 0.15 0.03 ± 0.01 0.3
T13D-F82D 1.19 ± 0.18 1.40 ± 0.27 0.12 ± 0.03 1.2
R85A 0.46 ± 0.22 1.58 ± 0.17 0.47 ± 0.34 4.7
T13D-R85A 0.58 ± 0.19 1.38 ± 0.22 0.26 ± 0.08 2.6
F82D-R85A 0.42 ± 0.12 4.10 ± 1.01 1.08 ± 0.50 10.8
T13D-F82D-R85A 0.30 ± 0.08 1.44 ± 0.19 0.51 ± 012 5.1
IL-13 Variant     relative K D (K D(mut)/K D(IL-13))
IL-13 - - - 1.0 (150 nM)
E11A - - - 233
R64A - - - > 1300
  1. Association and dissociation rates of IL-4 variants to immobilized IL4-RαECD were measured on a BIA2000 system. The rate constants represent mean values of 18 independent measurements with 6 different analyte concentrations. Binding affinities of IL-4RαECD to the complex of IL-13/IL-13variant bound to IL-13Rα1 were measured via the COINJECT command. Dissociation constants were obtained from equilibrium binding analysis, therefore no rate constants are given. Binding of the IL-13 variants to IL-13Rα1 was unaltered compared to wild-type IL-13.