Microscopic rate constant - oxidative half reaction

[QueenV]

Hello, this is my first post! I'm struggling slightly with predicting the km of my reaction,from the reaction mechanism, i'd just like to see which of two km values i've ascertained by two different practical methods is likely to be more accurate.

 

I'm working on a system which consists of a reductive and oxidative half reaction in a standard ping pong mechanism. I have conducted pre-steady state and steady-state assays to ascertain all the relevent kinetic parameters. I'm currently trying to see if km values predicted by the mechanism match those determined experimentally, I know the kd values and klim values but the mechanism i'm using states: km of oxidising substrate = k3(k6+k7)/k5(k3+k7).

 

k3 = klim of reductive half reaction, which I have.

k6 = kd associated with oxidative half reaction, which I have.

k7 = klim of oxidative half reaction, which I have.

K5 = association of enzyme-substrate complex?

 

This isn't a parameter I've measured, i've only ever measured the klim and kd for the oxidative half reaction...... I know it may seem obvious, but after looking at this for some time I can't see the wood for the trees! any help or advice pointing me in the right direction would be very much appreciated....