S. A. Bobrovnik¹*, O. V. Ogloblya², M. O. Demchenko¹, S. V. Komisarenko¹

¹Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
²ESC Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Ukraine;
*e-mail: s-bobrov@ukr.net

Received: 22 April 2021; Accepted: 22 September 2021

In order to determine thermodynamic parameters of the interaction between polyreactive immunoglobulins (PRIGs) and immobilized antigen, several of experimental kinetic curves of PRIGs binding to immobilized ovalbumin were obtained at different temperatures. This allowed determining the rate constants for every step of the binding process for each temperature. Then, using appropriate equations, thermodynamic parameters, such as activation energy, enthalpy, entropy, and standard free energy (Gibbs energy), were calculated. Thermodynamic values obtained show that the main energy consuming step in the study process of PRIGs bindingis the transformation of “inactive” PRIGs into “active” PRIGs, i.e. formation of hydrophobic patches on the surface of PRIGs molecules. In contrast, the following step of the binding of “active” PRIGs to an immobilized antigen is not an energy dependent process.