Tag Archives: antigen-antibody interaction

Effect of trifluoroethanol on antibodies binding properties

S. A. Bobrovnik*, M. O. Demchenko, S. V. Komisarenko

Department of Molecular Immunology, Palladin Institute of Biochemistry,
National Academy of Sciences of Ukraine, Kyiv;
*e-mail: s-bobrov@ukr.net

Received: 01 December 2022; Revised: 22 February 2023;
Accepted: 13 April 2023; Available on-line: 27 April 2023

The studies on the influence of organic co-solvents on the structure and function of antibodies are of key interest, especially in view of antibodies broad use as recognizing elements in different analytical systems. Here we studied the effect of co-solvent 2,2,2-trifluoroethanol (TFE) on the ability of anti-ovalbumin monoclonal antibodies to interact with its specific antigen. Antibody affinity to antigen and the rate constants of antibody binding to immobilized antigen were analyzed. Changes in antibody reactivity with incubation time which depended on TFE concentration and temperature were revealed. When treatment of antibodies with TFE was carried out at 0°C, we observed nonlinear, non-monotonous changes of antibody reactivity with initial fast decrease and substantial increase as incubation continued that may be related to the loss of antigen binding reactivity by some part of antibodies at the start but its restoration when the incubation proceeds.

Fundamental differences between natural antibodies and polyreactive immunoglobulins

S. A. Bobrovnik, M. A. Demchenko, S. V. Komisarenko

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: s-bobrov@bk.ru

A problem of similarity and differences between so-called polyreactive immunoglobulins (PRIGs) and natural antibodies (NAbs), capable of cross-reacting with some structurally dissimilar antigens, has been considered. The analysis of mechanisms of an unspecific interaction between PRIGs or NAbs and antigens evidences for the fact that essential differences exist between these substances. These differences permit classifying the abovementioned substances as different types of immunoglobulin molecules. The major difference between PRIGs and NAbs may include both the mechanisms of the above mentioned immunoglobulin molecules binding to antigens and their interaction affinity, as well as an absolutely different influence of some low-molecular substances on the efficiency of the interaction with antigens. Relying on the obtained data it can be assumed that, since PRIGs and NAbs have fundamental differences, they may perform not only similar but also different functions of the immune system.

Interaction peculiarities of polyreactive immunoglobulins and various antigens

S. A. Bobrovnik, M. O. Demchenko, S. V. Komisarenko

Palladin Institute of Biochemistry, National Academy of Sciences of Ukarine, Kyiv;
е-mail: s-bobrov@bk.ru

The influence of twin 20, lysozyme and protamine on the capability of polyreactive immunoglobu­lins (PRIG) to attach to various antigens was investigated. Twin 20 can inhibit the binding of PRIG to antigens on immunological plates but lysozyme and protamine can enhance it. As far as the mixture of the optimal concentrations of lysozyme and protamine cannot increase PRIG-antigen interaction in comparison to the optimal dose of protamine, we have concluded that the mechanism of their effect on PRIG binding is similar. Of special interest­ is the fact that twin 20 at optimal concentration of lysozyme or protamine does not decrease PRIG binding to various antigens but, on the contrary, increases PRIG-antigen interaction.