PubMed · 529816
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J E Scott. 1979-11-07. Hydrated electrons and prebiotic evolution.. https://doi.org/10.1016/0022-5193(79)90077-8
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The interaction of various lanthanide ions with vesicles of phosphatidylcholine from egg yolk has been followed by 31P NMR at 30 degrees C. From known magnetic properties of these ions, separation of the paramagnetic shift into a pure contact and a pseudo-contact part was carried out. Binding curves for the contact contribution (F curves) were obtained from vesicles in solutions of sodium salts with monovalent anions over a wide concentration range. These curves should be insensitive to any conformational effects due to ion binding. Indication of a conformational change in the lipid head group at low ion binding was obtained by studying the ratio between the contact and the pseudo-contact contributions. Besides the adsorption of lanthanide ions, specific anion binding to the surface was introduced to account for the enhanced chemical shifts (Cl- < Br- < NO3-). The results were analyzed in terms of the theory for the diffuse double layer (Gouy-Chapman-Grahame) with equilibrium conditions for the adsorbing cations and anions. Simulations of the titration curves furnished parameters for the ion-lipid interactions. The synergism between the cations and anions follows from the potential effects. Comparison of results with lanthanide ions and Ca2+ indicates that the anion adsorption probably depends on the nature of the adsorbed cation. Lanthanide ion binding to L-glycerophosphorylcholine is not influenced by sodium salts. The binding constant for this complex is weaker than with phosphatidylcholine. The chemical shifts for the lanthanide ion complexes with these two phosphorus compounds seem to be about the same.
The physical nature of small air ions is well established and it is recognized that they can produce a variety of biological effects. However, in only a few instances have any underlying biochemical changes been detected. Theoretically, one can consider the hydrated superoxide radical anion (O2) (H2O)n with n congruent to 4-8 as a likely candidate for a biologically active species of negative air ion. The chemical and biological reactivity of superoxide is high and includes a leading role in bacterial killing caused by radiation, in which superoxide dismutase (SOD), an enzyme that catalyses the reaction: O2 + O2 +2H leads to H2O2 +O2 protected markedly. Other studies have also demonstrated the bactericidal effect of O2 (refs 9-11). Inasmuch as the bactericidal action of small negative air ions has been repeatedly confirmed, we decided to test for the involvement of O2 in this phenomenon by evaluating the protective effect of SOD. Our results show strong O2 involvement in negative air ion bacterial kill.