Effect of Mercaptoethanol on Complement Binding Ability of Human 7 S Gammaglobulin.

The effect of mercaptoethanol on the ability of human 7 S-antibodies and human 7S gammaglobulins (γ2) to react with antigen, complement and rheumatoid factor was studied. 1. Human 7 S-immune globulin continued to combine with antigen after mercaptoethanol treatment. 2. Human gammaglobulin, treated with mercaptoethanol, could be aggregated by heat as measured by the ability to precipitate with a potent rheumatoid factor. 3. Mercaptoethanol treatment of 7 S-antibodies and gammaglobulin resulted in a loss of ability to fix complement after reacting with antigen or after nonspecific heat aggregation respectively. These results stress the importance of disulfide bonds in the complement fixation reaction.