The enzyme-substrate complex as a cat state: A toy quantum analog

Area of Science:

• Biophysics
• Quantum Chemistry
• Enzyme Kinetics

Background:

• Enzyme action involves complex conformational changes and quantum mechanical effects like tunneling.
• Understanding the role of quantum superposition in enzyme-substrate interactions is crucial for elucidating catalytic mechanisms.

Purpose of the Study:

• To develop a quantum model system for enzyme action that includes tunneling and conformational superposition.
• To analyze how quantum superposition of enzyme-substrate complex conformations affects reaction rates and stability.

Main Methods:

• Introduction of a solvable quantum model system with potential barriers representing enzyme conformations.
• Analysis of quantum dynamics, including superposition states and their impact on substrate-to-product conversion rates.

Main Results:

• Quantum superposition can either enhance or suppress substrate-to-product conversion rates compared to fixed conformations.
• Bound states can emerge in superposition, potentially increasing complex stability.
• Superposition of finite and infinite barriers paradoxically enhanced conversion rates.

Conclusions:

• Enzyme-substrate binding to a superposition of conformations may be advantageous over fixed conformations.
• Conditions within living cells that could support enzyme action via conformational superposition are analyzed.
• The study provides a theoretical framework for exploring quantum effects in biological catalysis.