Protective Value of ‘Univalent’ Antibodies Produced by Photo-Oxidation of Antipneumococcal Rabbit-Serum and Antidiphtheric Horse-Serum

摘要

1. (1) When type 1 antipneumococcal rabbit-serum is photo-oxidized to the point where it becomes non-precipitating, it exhibits approximately half the mouse-protective value of the control antiserum. The protective value drops off rapidly towards zero upon further photo-oxidation while the precipitation-inhibiting titers (a measure of ‘univalent’ antibodies) pass through a maximum.2. (2) By salting-out and by electrophoretic methods precipitating (‘multivalent’) antibodies are obtained from the first non-precipitating antiserum and are found to account for the protective action of the antiserum. On the other hand the fast electrophoretic component, obtained from a more highly photo-oxidized sample, shows a high precipitation-inhibiting titer but no appreciable protective action.3. (3) It is concluded that the ‘univalent’ type of antibody is ineffective for passive protection against bacteria.4. (4) When antidiphtherial-toxin horse-serum is photo-oxidized to the point where it becomes non-flocculating it still gives the same antitoxic value as the control. Upon further photo-oxidation the antitoxic value drops off very slowly. The results indicate that ‘univalents’ may function as protective antibody against toxins.5. (5) Photo-oxidation effects an increase in electrophoretic mobilities and a decrease in number of components indicative of an interaction of the serum-proteins.