The Antigen-Antibody Reaction with Type A Botulinal Toxin

[摘要] Crystalline botulinal type A toxin has been found to behave as a complete antigen. It is capable of inducing antibody-formation and a state of supersensitivity. Combination with antibody in the flocculative reaction is in harmony with its large molecular size.Toxin and toxoid appear capable of forming insoluble complexes with normal sera. Some of the characteristics of the complexes are outlined. The particular importance of the temperature-variable made it necessary to study the precipitin-reaction with a given antiserum at several different temperatures. In the quantitative precipitin-studies the phenomenon was notable in the zone of antigen-excess and at lower temperatures.In the quantitative precipitin-reaction there exists, in the zones of equivalence and antitoxin-excess, a curvilinear relation between the ratio of antibody to antigen in the precipitates and the quantity of antigen added. (The relation is expressed by the exponential equation x = ab y where x = antigen added, y = the ratio, and a and b are constants.) If the ratio is plotted against the log of the quantity of antigen added, a linear relation results. Results with the quantitative precipitin-reaction vary for sera from different animals. With horseserum, inhibition in the antibody-excess zone may be complete, and may even extend to the equivalence-zone.With both horse- and rabbit-sera inhibition of precipitation was not noticed in the zone of antigen-excess. This finding is discussed.Flocculation of toxoid (prepared by treatment with formaldehyde at pH 7) with antitoxin was studied. Though quantitative differences existed, in general the qualitative findings were like those with toxin.In titrations by optimal-proportions, a Lederle ‘modified-globulin’ horse-serum gave an “H” type reaction with toxin and an “R” type reaction with toxoid, an individual rabbit-serum gave “H” type reaction with toxin and a pool of rabbit-sera gave an “R” type reaction with both toxin and toxoid.

[学科分类] 生物科学（综合）