Development of an intravenous gamma-globulin with Fc activities. I. Preparation and characterization of S-sulfonated human gamma-globulin.

S-sulfonated gamma-globulin (S-GG) was prepared by treating gamma-globulin with sulfite and tetrathionate ions. About four interchain disulfide bonds were selectively cleaved to give S-sulfonate groups. Although the above treatment strongly suppresses anticomplementary activity and nonspecific skin reactivity, the resulting S-GG retains high antibody activity. Furthermore, S-GG was found to maintain satisfactory levels for prolonged periods in vivo. The physicochemical and antigenic analyses of S-GG suggest that the S-sulfonation induces structural modification only at restricted sites.