1. What is Enzyme Substrate Inhibitor Complex Concentration?

Definition: The Enzyme Substrate Inhibitor (ESI) Complex Concentration is the molar concentration of the complex formed when an uncompetitive inhibitor binds to the enzyme-substrate complex.

Purpose: This calculation helps biochemists and pharmaceutical researchers understand enzyme kinetics in the presence of inhibitors.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( ESI \) — Enzyme Substrate Inhibitor complex concentration (mol/m³)
• \( ES \) — Enzyme Substrate complex concentration (mol/m³)
• \( I \) — Inhibitor concentration (mol/m³)
• \( K_i' \) — Enzyme substrate dissociation constant (mol/m³)

Explanation: The concentration of ESI complex is directly proportional to both ES complex and inhibitor concentrations, and inversely proportional to the dissociation constant.

3. Importance of ESI Complex Calculation

Details: Understanding ESI complex formation helps in drug design, enzyme inhibition studies, and biochemical pathway analysis.

4. Using the Calculator

Tips: Enter the enzyme-substrate complex concentration, inhibitor concentration, and dissociation constant. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is an uncompetitive inhibitor?
A: An uncompetitive inhibitor binds only to the enzyme-substrate complex, not to the free enzyme.

Q2: How is K_i' different from K_i?
A: K_i' is the dissociation constant for the ESI complex, while K_i is for the EI complex in competitive inhibition.

Q3: What units should I use?
A: The calculator uses mol/m³, but you can use any consistent units as long as all inputs use the same units.

Q4: How do I determine the ES complex concentration?
A: ES concentration can be measured experimentally or calculated from enzyme kinetics equations.

Q5: What affects the dissociation constant?
A: Temperature, pH, and the specific enzyme-inhibitor interaction all influence K_i'.