Change reaction rate from antibody-ligand interaction to enzyme-mediated ligand depletion

Hi all,

I have a question regarding a change I want to implement into a PK/PD model. Currently, the model is based on an antibody-mediated clearance of a Ligand: mAb + L --> mAb~L complex formation (mAb: monoclonal antibody), followed by its clearance from plasma (screenshot 1). I want to maintain exactly the same model's properties and parameters but replace the antibody with an enzyme for depletion of the ligand (screenshots 2, 3): E + L --> E + P (where P is the product of the reaction which will be cleared from plasma, but the Enzyme will still be present in plasma after the reaction). I am thinking that this is a different scenario as compared to the antibody because while in case of the antibody the antibody-ligand complex is cleared from plasma leading to a decrease in antibody concentration (stoichiometric binding), whereas in contrast, in case of the enzyme, only the ligand is cleared with a rate defined by the enzyme's kinetic properties. I tried to select from the Kinetic Law's dropdown menu, the Henri-Michaelis-Menten law such that I could introduce the terms Km and Vmax into the reaction rate relationship/formula.

I was wondering as to whether this is the correct way to do it and seek for advice about potentially additional suggestions. Would my approach above be the correct way to do it and then simply assign some values for Km and Vmax? Or are there additional modifications I would need to perform?

Any insights into this question are highly & greatly appreciated.

I attach here the simbiology file and the screenshots I referred above.

Thank you!

Christos