Apparent Michaelis Menten constant given Inhibitor's Dissociation Constant Calculator

Apparent Michaelis Constant Formula:

\[ K_{m}^{app} = K_M \times \left(1 + \frac{[I]}{K_i}\right) \]

Michaelis Constant (K_M):

Inhibitor Concentration ([I]):

Enzyme Inhibitor Dissociation Constant (K_i):

Apparent Michaelis Constant (K_m^app): %

1. What is Apparent Michaelis Menten Constant?

Definition: The Apparent Michaelis Constant is defined as the Michaelis-Menten constant in the presence of a competitive inhibitor.

Purpose: It helps biochemists and enzymologists understand how inhibitors affect enzyme kinetics.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ K_{m}^{app} = K_M \times \left(1 + \frac{[I]}{K_i}\right) \]

Where:

\( K_{m}^{app} \) — Apparent Michaelis Constant (%)
\( K_M \) — Michaelis Constant (%)
\( [I] \) — Inhibitor Concentration (%)
\( K_i \) — Enzyme Inhibitor Dissociation Constant (%)

Explanation: The Michaelis Constant is multiplied by a factor that accounts for the inhibitor concentration relative to its dissociation constant.

3. Importance of Apparent Michaelis Constant

Details: This calculation is crucial for understanding competitive inhibition in enzyme kinetics and drug interactions.

4. Using the Calculator

Tips: Enter the Michaelis Constant, Inhibitor Concentration, and Dissociation Constant. All values must be > 0 (except inhibitor can be 0).

5. Frequently Asked Questions (FAQ)

Q1: What does the apparent Michaelis constant tell us?
A: It shows how much a competitive inhibitor increases the measured K_M of an enzyme reaction.

Q2: What's a typical value for K_i?
A: This varies widely depending on the enzyme and inhibitor, often in the micromolar to millimolar range.

Q3: When would K_m^app equal K_M?
A: When [I] = 0 (no inhibitor present) or when K_i is very large (very weak binding).

Q4: How does this relate to drug development?
A: Competitive inhibitors are often drug candidates, and this calculation helps predict their effects.

Q5: Can this calculator be used for non-competitive inhibition?
A: No, this formula is specific for competitive inhibition.