Rapidly released allergens from short ragweed pollen. II. Identification and partial purification.

We have identified several basic allergens in 16-min extracts of short ragweed (Ambrosia elatior) pollen and obtained a partially purified fraction (G50 II) using a combination of ion-exchange (CM-Sephadex C25) and gel-filtration (Biogel P30 and Sephadex G50) procedures. G50 II was allergenically and antigenically distinct from known allergens antigen E, Ra3, and Ra5. It gave a highly symmetrical peak on Sephadex G50 (fine), corresponding to a molecular weight of 11,500 daltons, and a single band on SDS polyacrylamide gel electrophoresis under both reducing and nonreducing conditions. However, two cathodic antigens were detectable by both agarose electrophoresis and crossed immunoelectrophoresis. Allergenic activity of G50 II, assessed by puncture testing in ragweed-sensitive subjects, showed a characteristic pattern of response independent of patient response to AgE, Ra3, and Ra5. The major antigenic and allergenic component of G50 II is designated Ra6.