RADIOCHEMICAL STUDIES ON THE INFLUENCE OF PHOTOGRAPHICALLY ACTIVE SUBSTANCES ON THE KINETICS OF THE TRANSFER OF SUBSTANCES TO SILVER-HALIDECRYSTALS .11. THE INFLUENCE OF ALKALINE METAL-IONS, EARTH ALKALINE METAL-IONS AND EARTH METAL-IONS

In the present paper the influence of some alkaline metal ions, earth alkaline metal ions and earth metal ions on the kinetics of the I-131- mass transfer is investigated in the system AgI-gelatine-I-131(-). Fro m the dependence of the activation parameters of the I-131-mass transf er on the concentration of the Li+-, Mg+-, Ca2+- and Al3+-ions, respec tively (as Cl- and NO3-, respectively), statements can be derived for the interaction of these ions with the gelatine in the temperature ran ge of the unfolded and folded gelatine. In this case it could be shown that the Ca2+-ions in low concentrations cause an influence on the fo lding of the gelatine. Higher Ca2+-concentrations shift the beginning of the formation of the triple helix to lower temperatures. In the tem perature range of the unfolded gelatine, Mg2+- and Ca2+-ions cause an association of the gelatine macromolecules which leads to a decrease o f the velocity of the I-131-mass transfer. The addition of a larger am ount of the lice in the presence of a higher concentration of Ca2+-ion s leads to a splitting of the associated gelatine macromolecules. The binding of the Ca2+-ions with gelatine and, therefore, the velocity of the Ostwald ripening and the folding processes during the formation o f the triple helices is determined mainly by the concentration of the carboxyl groups in the gelatine. A new method is presented which chara cterizes the supra-molecular interaction between proteins and inorgani c and organic substrates, respectively. The advantages and the disadva ntages of this method will be discussed in detail.