Funny looking data

Hi I recently performed an experiment to determine the Kd of a1500 Da small molecule to a 41000 Da protein. I immobilized about 5000 RU of the protein and got a series of curves that all look the image. I am not sure what to make of it. Did I immobilize too much or too little protein?

image didn't add the first time. here it is

Since the scales are not visible I cannot say anything about the response level. Also is this original or processed data? The shape of the curve seems to have a kind of lag at the starting point and maybe some mass-transport. Overall the curves look fine. Dissociation seems not to go to baseline. Always difficult to find out why not. Immobilizing less ligand can sometimes do the trick.

Kind regards
Arnoud

The data has been processed. The curves max out at 90 RU. I was expecting the different concentrations to have different intensities but this is not the case.

Try a wider concentration range. Say 4-5 concentrations and dilute with a step 5x. Also inject an zero concentration (dilution of buffer of the analyte + running buffer) to check that this is not a problem.