Michaelis Constant

Introduction

Constant of Michaelis-Menton kinetics in which an enzyme binds substrate to reversibly form an intermediate enzyme-substrate complex which then dissociates to form product (or regenerates substrate.

       k1         k3
E + S  -->    ES  -->    E  +  P
      <--
       k2

E = enzyme, S = substrate, P = product

Km = (k2 + k3)/k1

It is equal to the substrate concentration at which the enzymatic reaction occurs at 1/2 maximum velocity.

A low value for the Michaelis constant indicates that dissociation of the ES complex to form product occurs much faster than dissociation to regenerate substrate

Additional terms

• Michaelis-Menton kinetics