BIOLOGICAL AND CHEMICAL DIFFERENCES AMONG PROTEINS HAVING REAGINIC ACTIVITY

The reaginic properties of eleven human sera and/or their chromatographic fractions were examined with the use of physicochemical and biological methods. Proteins with reaginic activity were found to be markedly heterogeneous with regard to their elution characteristics from DEAE columns and with respect to their skin-fixing properties. Certain differences were also noted with respect to the degree of sensitivity of these proteins to sulfhydryl splitting agents. It remains to be learned if the heterogeneity demonstrated in these experiments is compatible with the concept that reaginic activity is associated with a single class of immunoglobulins. © 1968.