The Michaelis–Menten equation, proposed by Leonor Michaelis and Maud Menton in 1913, is the rate equation for a one-substrate enzyme-catalyzed reaction. While most enzyme-catalyzed reactions have more than one substrate, the Michaelis-Menton equation is still applied if only one substrate concentration is varied.
The Michaelis–Menten equation states that the product formation rate v depends hyperbolically on [S], and is depicted mathematically as follows:
where [S] is the substrate concentration and Vmax is the maximum velocity at saturating substrate concentrations. Km is the Michaelis constant, defined as the substrate concentration at which V attains half the value of Vmax.
To implement the Michaelis-Menton plot within CDD:
- Create readouts for input data such as concentration [S] and initial reaction rate [v]
- Creating a plot type readout to generate the curve fit
- Editing and saving the curve
Let’s work through an example implementing this curve fit within our “Michaelis-Menten” Protocol.
Create a numerical readout for the X-axis values:
Create a numerical readout for the Y-axis values:
Create a plot readout, which will create the plot and automatically calculate additional values:
Our protocol now captures our input data and automatically generates a Michaelis-Menten plot for each entity per run of the protocol.
The following parameters will automatically be calculated by CDD Vault for this plot type:
- Vmax
- Km
- Maximum measured v
- Minimum measured v
- N
- R squared
- Area under the curve - observed
Area under the curve
- The CDD Vault AUC is calculated as the (positive area - negative area) under the dose response curve where:
- The curve is defined as straight line connections between responses, not the fitted curve (Linear Trapezoidal Non-uniform grid method)
- Units are response units * independent units
- The baseline is set at the negative control mean or 0 if control data is not available
Additional calculations:
Please note that all auto-calculated parameters listed above can be used in custom calculations as separate readouts. These parameters can be accessed within our robust formula editor.