Change in antibody conformation induced by hapten.

Abstract
The rate of chymotryptic proteolysis of intact antibody and of Fab fragments of antibody is less when hapten is bound to the antibody site than when the antibody site is not occupied by hapten. This result was obtained with 2 different antibodies and the effect of haptens was shown to be specific by a paired label technique. The results provide evidence that the confirmation of an antibody molecule whose site is occupied by hapten is different from that of the free antibody.