Enzyme Activation Analysis

This custom protocol fits the data for an activation profile of an enzyme.  In my case, plasminogen is activated to plasmin in the presence of the chromgenic substrate S2251 (or can use a fluorogenic substrate) and tissue plasminogen activator.  Since the zymogen (which has no chromogenic activity) is being activated to a protease (which will cleave the substrate S2251) the data produces curves in an upward direction. Since we need to know the increase of the rate from point-to-point, the data must be fitted to a "times-squared" model (similar to an acceleration model). This linearizes the data for analysis.  The slopes of the "times squared" fit are proportional to the rates of activation.