Different curves in the Binding assesment assay

Dear Arnoud,
Kindly take a look on the attachment. This was the binding assay of amino acids to my protein. What the peaks of lysine and cysteine infer?.
Is it like "Primary analyte binding induces conformational changes on the protein to bind with more analyte"?
OR non-specific binding were more for these analytes?
instrument: Biacore 3000

It looks like that the lysine and cysteine are aggregating on the protein.
Conformational change does not alter the response since during the change no mass is gained or removed.

this publication could be of help:
Giannetti, A. M., Koch, B. D. and Browner, M. F.; Surface Plasmon Resonance Based Assay for the Detection and Characterization of Promiscuous Inhibitors. Journal of Medicinal Chemistry (51) 3: 574-580; 2008.

Regards
Arnoud