The total quasi-steady-state approximation is valid for reversible enzyme kinetics

Area of Science:

• Biochemistry
• Enzyme Kinetics
• Chemical Kinetics

Background:

• The Briggs-Haldane approximation is a classic quasi-steady-state approximation for irreversible enzyme kinetics.
• The reversible Michaelis-Menten scheme is less characterized, posing a limitation for understanding enzyme mechanisms.
• Reversible enzyme reactions are common, even those proceeding to completion.

Purpose of the Study:

• To derive a total quasi-steady-state approximation (tQSSA) for the reversible Michaelis-Menten scheme.
• To define the validity domain for the tQSSA.
• To develop a method for estimating kinetic parameters in reversible enzyme systems.

Main Methods:

• Derivation of the total quasi-steady-state approximation (tQSSA).
• Analysis of uniformly valid approximations for low and high enzyme concentrations.
• Development of a sequential experimental-theoretical method for parameter estimation.

Main Results:

• The tQSSA provides a uniformly valid approximation for reversible Michaelis-Menten kinetics.
• The approximation holds for low enzyme concentrations (ET<
• A novel method enables unambiguous estimation of all kinetic parameters for the reversible Michaelis-Menten scheme.

Conclusions:

• The tQSSA offers a robust framework for analyzing reversible enzyme kinetics.
• This approximation addresses limitations in characterizing reversible Michaelis-Menten schemes.
• The proposed method facilitates accurate determination of enzyme kinetic parameters.