Nernst-Michaelis-Menten framework unlocks electrochemical kinetics for laccases

Area of Science:

• Biochemistry
• Electrochemistry
• Enzyme kinetics

Background:

• Spectrophotometric methods for determining oxidoreductase kinetic parameters are limited.
• Accurate characterization of enzyme kinetics is crucial for understanding biological processes and developing new biotechnologies.

Purpose of the Study:

• To develop an innovative approach for determining oxidoreductase kinetic parameters.
• To overcome the limitations of existing spectrophotometric methods.
• To provide a versatile tool for enzyme characterization.

Main Methods:

• A novel Nernst-Michaelis-Menten theoretical framework was developed.
• This framework integrates the Nernst equation with Michaelis-Menten kinetics.
• Chronopotentiometry was employed for kinetic parameter determination using a commercial laccase enzyme.

Main Results:

• Precise kinetic parameters were measured for both chromophoric (ABTS) and non-chromophoric (hydroquinone) substrates.
• The K_m for ABTS was determined to be (56.7 ± 6.3) microM, and for hydroquinone, it was (196 ± 59) microM.
• The method was validated against established techniques and demonstrated to require minimal enzyme quantities for rapid analysis.

Conclusions:

• The Nernst-Michaelis-Menten framework offers a powerful and accurate method for oxidoreductase kinetic parameter determination.
• This approach overcomes limitations of conventional spectrophotometric methods and expands the range of analysable enzymatic systems.
• The method provides a new paradigm for enzyme kinetics and characterization, applicable to various oxidoreductases.