Table 1.

Electrostatic contribution to the k₁ rate constant¹

Interaction	−U/RT (kcal mol−1)	${{\displaystyle k}}_1^0$ (M−1 s−1)
IL-7/IL-7R (EC)	0.90 ± 0.1	8.6 ± 1.2 × 102
IL-7/IL-7R (CHO)	8.1 ± 0.7	1.8 ± 0.6 × 104
IL-4/IL-4R	5.7 ± 0.8	6.3 ± 2.7 × 105

¹−U/RT were obtained from the slopes of the lines from Fig. 3B. Binding kinetics were measured at pH 7.4 and 298 K.