I suppose the answer depends on what epitope the antibody is raised against. If the antibody was raised against the cleavage site, where (presumably) CL-82198 also binds, then the inhibitor could potentially "compete it out" -- depending on the quantities of both materials present relative to their respective dissociation equilibrium constants. But if the antibody is raised against some peptide sequence that is characteristic for the MMP-13 protein but _not_ the same physical site where CL-82198 binds, then no matter how much CL-82198 is present the MMP13/antibody interaction will not be disrupted and therefore MMP-13 availability for antibody binding will not change.

I suggest first looking up the epitope information. If the the antibody binds at a site distal from the inhibitor binding site, this answers the question already (no effect). If it's the same binding site, I would then look up or measure the Kd for the antibody; and also look up the Kd for the inhibitor (it's seems to be single-digit nanomolar, but I only glanced at the Wyeth paper extremely quickly). That information will tell you how much of each material (antibody vs. inhibitor vs. enzyme) would have to present to achieve or avoid a significant effect of CL-82198 on antibody binding.

If you wanted to get somewhat rigorous about this type of experimental design, I'd like to recommend the free (for academic users) software package DynaFit:

http://www.biokin.com/dynafit/

Here is a little DynaFit script you could use to study this problem:

_______________________________________________

[task]

task = simulate

data = equilibria

[mechanism]

MMP-13 + Ab MMP-13.Ab : Kd(Ab) dissociation

MMP-13 + CL-82198 MMP-13.CL-82198 : Kd(CL) dissociation

[constants]

Kd(Ab) = ...

Kd(CL) = ...

[concentrations]

MMP-13 = ...

Ab = ...

[data]

variable CL-82198

mesh from ... to ... step ...

directory ...

extension txt

file MMP | response MMP-13 = 1

file MMP-13_Ab | response MMP-13.Ab = 1

file MMP-13_CL-82198 | response MMP-13.CL-82198 = 1

[output]

directory ...

[end]

_______________________________________________

This will generate three tab delimited text files, showing the equilibrium concentrations of free MM-13 and the two non-covalent complexes (MMP-13.Ab and MMP-13.CL-82198) depending on the total amount of of each component present.

Please feel free to contact me through

http://www.biokin.com/contact.html

if you need more information or assistance.

-Petr