EQUILIBRIUM AND KINETIC-PARAMETERS OF INTERACTION OF STROPHANTHIN-K AND ITS PEROXIDASE CONJUGATES WITH SOLUBLE AND IMMOBILIZED SPECIFIC ANTIBODIES

The rate constants for the formation and dissociation and the equilibr ium dissociation constants of strophanthin K complexes with specific a ntibodies (soluble and immobilized on activated polystyrene beads and polyamide membranes) were measured by ELISA. The dissociation constant s of the soluble and immobilized immune complexes measured by ELISA ar e in good agreement with the association constants of these complexes determined by the Scatchard method. The values of the kinetic and equi librium constants of interaction of strophanthin K and its peroxidase conjugate with antibodies correspond to the different nature of the in teracting particles and their environment; immobilized strophanthin-an tibody complexes are more stable than the complexes in solution; the i nteraction of strophanthin with immobilized antibodies is slower than with soluble antibodies. Strophanthin reacts with antibodies in soluti on and on solid matrices of different polymeric nature more rapidly th an its conjugate.