Forum :: which one to use for affinity Kinetics or Steady-state?


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This forum is intended for questions about kinetics, Surface Plasmon Resonance and the instruments related to these techniques.

TOPIC: which one to use for affinity Kinetics or Steady-state?

which one to use for affinity Kinetics or Steady-state? 03 Sep 2017 23:36 #1

Hi all,
I'm testing a novel small compound (300Da) for binding to a protein (22000Da) and it seems to bind, but I am not sure which model to use to determine the KD of that interaction.
If I use 1:1 binding it's KD in macromolar range, but if I apply steady-state model than its pM ???
I attached the graph.
Also, can KD depend on flow rate? and what does it mean?
Attachments:

which one to use for affinity Kinetics or Steady-state? 04 Sep 2017 09:28 #2

For this kind of data I would use the steady state interaction.
The association and dissociation rates are to fast to be reliable determined with a 1:1 kinetics model (also the jump in front of the association will not help).

The kinetics should be independent of the flow rate (and ligand density) provided that there is no mass transport limitation.

Kind regards
Arnoud
Last Edit: 04 Sep 2017 09:29 by Arnoud.
The following user(s) said Thank You: devinet
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