Unusual Sedimentation and Sulfhydryl Sensitivity of Certain Isohemagglutinins and Skin-Sensitizing Antibody. ∗

Abstract

Summary

Improved methods of density gradient ultracentrifugation have demonstrated that, in addition to the well-known 7S and 19S class antibodies, antibodies with intermediate sedimentation rates exist. Analysis of certain isohemagglutinins in whole sera and purified fractions have shown that a large proportion of the antibodies have sedimentation rates in the range of 9-15S. These antibodies, clearly separable from 19S class proteins, were inactivated by treatment with 0.1M mercaptoethanol. A skin-sensitizing antibody reacting with highly purified glucagon had a sedimentation rate in the range of 8-11S. The ability of this reaginic antibody to sensitize skin as measured by the classic Prausnitz-Kustner reaction also was inactivated by treatment with 0.1M mercaptoethanol. The possible relationship of these antibodies to the β_2A class of immunoglobulins is discussed.