ACCU-RATES: A Web Tool for Accurate Enzyme Kinetics and Initial Reaction Rate Measurements.

Area of Science:

• Biochemistry
• Enzymology
• Computational Biology

Background:

• Accurate initial reaction rate (v0) determination is critical for enzyme kinetics, inhibitor design, and biological modeling.
• Traditional methods often rely on linear approximations or require specific assay conditions that may not capture true rates.
• Substrate excess alone does not guarantee constant reaction velocities, posing challenges for precise kinetic analysis.

Purpose of the Study:

• To develop a user-friendly web tool, ACCU-RATES, for accurate determination of initial reaction rates (v0) from enzyme progress curves.
• To overcome the limitations of traditional methods by employing a numerical approach to kinetic parameter estimation.
• To provide a robust and reliable method for calculating kinetic parameters like Michaelis constant (Km) and limiting rate (V).

Main Methods:

• Development of ACCU-RATES, a web tool analyzing product accumulation or substrate depletion curves with at least two data points.
• Application of the differential form of the Michaelis-Menten equation for numerical fitting of progress curves.
• Interpolation of initial reaction rates (v0) using the fitted kinetic model.

Main Results:

• ACCU-RATES enables precise interpolation of v0, leading to accurate determination of Km and V.
• Simulations demonstrate reliable and user-independent parameter estimates, even with noisy data or low sampling rates.
• The tool provides superior accuracy and robustness compared to existing methods, unaffected by assay interferences.

Conclusions:

• ACCU-RATES offers a significant advancement in determining enzyme kinetic parameters from progress curve data.
• The tool enhances accuracy and reliability in enzyme characterization, inhibitor discovery, and synthetic biology applications.
• ACCU-RATES is freely accessible, promoting wider adoption and facilitating research in enzymology and related fields.