What is the effect of the rate of immobilization of the ligand on the ka, kd and KD?
I think you mean:
What is the effect of the immobilization density of the ligand on the ka, kd and KD?
In general a high immobilization density gives rise to all kinds of side effects masking the true kinetics of your system.
In steady state the KD is the result of all these interactions.
The association phase will probably not be 1:1 and the high ligand density favours rebinding during dissociation.
For kinetics the lowest ligand density with a good response (say 100 RU) is the best.
Arnoud