Abstract
The monomers obtained by treating gamma(1)-macroglobulins with mercaptoethanol have proved to be antigenically different from normal 7S 7gamma-globulin. The depolymerization of the macroglobulins resulted in the loss of several antigenic determinants, although the monomers still cross-reacted with antisera against macroglobulins. Reaggregation of the monomers occasionally resulted in the reconstitution of some or all of the antigenic determinants that were lost during depolymerization. Repeated freezing and thawing of pathological macroglobulins in iodoacetate resulted in their complete antigenic destruction. Repeated freezing and thawing of one of the monomers in excess iodoacetate resulted in the degradation to a protein antigenically indistinguishable from Bence Jones protein. The other two monomers studied were stable under these conditions.