TABLE 2.

Kinetic and affinity constants for the interactions of TIAR123, TIAR12, and HuR12 proteins with U-rich and C-rich RNAsa

ProteinRNAKa (1/M−1 s−1)Kd (1/s)KD (Kd/Ka [nM])
HuR12U rich(1.29 ± 0.01) × 1084.35 ± 0.0333.73 ± 0.50
TIAR123U rich(1.58 ± 0.02) × 106(1.56 ± 0.01) × 10−30.99 ± 0.02
C rich(2.72 ± 0.03) × 104(36.78 ± 0.12) × 10−4135.2 ± 1.93
TIAR12U rich(4.10 ± 0.11) × 106(2.83 ± 0.08) × 10−30.69 ± 0.04
C rich(3.48 ± 0.04) × 104(19.64 ± 0.06) × 10−456.39 ± 0.79
  • a The association and dissociation rate constants (Ka and Kd) were determined as global fitting parameters for a 1:1 binding model. The equilibrium dissociation constant, KD, was determined as Kd/Ka.