Development of an intravenous gamma-globulin with Fc activities. II. Reconversion of S-sulfonated human gamma-globulin into the original gamma-globulin.

The reconversion of S-sulfonated antitetanus gamma-globulin (S-GG) into the original gamma-globulin was studied. S-sulfonate groups in S-GG could be converted into disulfide bonds in vitro. The conversion restored the greater part of both complement-fixing and skin-sensitizing activities. S-GG administered intravenously formed interchain disulfide bonds again in vivo, which was accompanied by restoration of the C-dependent passive hemolytic activity. Intravenous injection of S-GG did not cause a significant decrease in serum complement level.