Tetanus Toxin and Antigenic Derivatives II. Effect of Protein and Formaldehyde Concentration on Toxoid Formation

Abstract

Tetanus toxoid formation was examined under varying conditions. Products of the reaction depended upon the concentration of both formaldehyde and toxin. High concentrations of protein and formaldehyde favored the formation of large polymers, whereas low concentrations yielded smaller polymers and monomer. The monomer had an observed S value of 7.1, whereas the polymers ranged from lOWS to llOS. The cross-linking between toxin molecules to form toxoid polymers appeared to be random.

Some properties of staphylococcal alpha-toxoid

“…The results tidicate that, with the concentrations of protein and formaldehyde used, the conversion of staphylococcal a-toxin to toxoid is not accompanied by an increase in molecular size and therefore does not involve polymerization. This finding contrasts with the behavior of tetanus toxin (sedimentation coefficient = 6.4S), which gives rise on toxoiding to a 7.15 monomer and to polymers about 35 times as large as the monomer (4). In addition, our results show that toxoiding of a-toxin results not only in loss of toxic (hemolytic) and spherule-disrupting activities but also in loss of ability to polymerize on contact with spherules.…”

Effect of Formalin Treatment on Electrophoretic Mobility of Cholera Toxin

“…The present study indicates that treatment of cholera toxin with Formalin induced increased electrophoretic mobility of the antigenic moiety in disc electrophoresis consistent with either increased net negative charge or polymerization of the molecular entity, or both. Increased net negative charge would be expected from formation of methylol derivatives from amino groups due to Formalin treatment, and polymerization of protein toxins is a well-known effect of Formalin on tetanus toxin (6). Cross-linking of toxin molecules with other proteins present in crude-culture filtrates is another possibility.…”