Antigen-binding activity of monoclonal antibodies after incubation with organic solvents.

Effects of four organic solvents--methanol, trifluoroethanol, dimethylsulfoxide, and dimethylformamide (DMF)--on the ferritin-binding activity of three monoclonal mouse antibodies of IgG2a and IgG1 subclasses were studied. The ferritin-binding constants of monoclonal antibodies G10 and F11 (the IgG2a subclass) were increased 2-6-fold after incubation with DMF and removal of the organic solvent by gel filtration. The maximum effect on the F11 antibodies was found in the presence of 5-13% DMF and on the G10 antibodies at 11-40% DMF. The effect remained after the removal of DMF from the incubation medium, and this suggests that the incubation with DMF resulted in irreversible conformational changes of the antibodies and in production of active conformers of the G10 and F11 antibodies. These conformations occurred within 15-60 min. The long-term stability and the fluorescence of the antibodies exposed to DMF suggest that the conformational changes were not global, but involved small and relatively independent structural elements of the antibodies, either of hypervariable CDR loops in variable domains or of the hinge region of the antibodies. The affinity of the C5 antibodies of the mouse IgG1 subclass was decreased after incubation with DMF. The activation was a solvent-specific effect because incubation of the G10 antibodies with methanol and dimethylsulfoxide decreased the affinity for the antigen, and incubation with trifluoroethanol virtually did not affect it. Relatively small changes in the antigen-binding activity of the antibodies were found even after the incubation with 5% organic solvent.

[Choice of parameters of primary transformers of body surface fluctuations]. / Vybor parametrov pervichnykh preobrazovatelei kolebanii poverkhnosti tela.

The authors review distortions of body surface fluctuations provoked by the action of primary transformers (PT). It is suggested that conditions of PT contact with the body surface may be standardized. As far as transformers measuring the kinematic parameter of fluctuations are concerned, those existing in the absence of any action on the surface should be regarded as undistorted. As for PTs that transform the power parameter, the conditions for undistorted reception involve complete inhibition of the surface under study. It is proposed that the degree of distortions may be estimated in the form of the "measurement method error". It is shown that error of the method can be restricted at the present level, if the design parameters of PT that determine the conditions of contact are chosen in terms of the correlations provided in the paper.