correlation of IC50 to receptors/enzyme molecules

[interpreneur_org at yahoo.com]

In a binding or kinetic assay, how does the IC50 of a compound change with respect to the number of receptors/enzyme molecules available? Is it linear (e.g: 10 times more protein leads to a 10 fold increase in the IC50)? Or not? And what is the mathematical equation explaining this?

Thanks!

Lisa.


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