A RELIABLE METHOD TO ESTIMATE THE ASSOCIATION CONSTANT FOR A MONOCLONAL-ANTIBODY AND A PROTEIN ANTIGEN BY ENZYME-LINKED-IMMUNOSORBENT-ASSAY, ELISA

The association constant K-a for mouse monoclonal antibody raised against human angiotensinogen was calculated using a mathematical model, SAM I. K-1 represents the equilibrium constant for the binding of antibody to the solid phase with antigen previously absorbed. K-2 represents the interaction between antibody and antigen in solution (Ag + Ab = AgAb). K-3 represents binding to the antigen absorbed bed on the solid phase by an antigen-antibody complex. K-4 represents the second binding of the antigen to the antigen-antibody complex (AgAb + AgAb = (Ag)2Ab). The model unveils cooperativity for the first (K-1 and K-2) and second (K-3 and K-4) binding of antigen to antibody. The model gives the association constant in a high affinity interaction between antigen and antibody.