An immunoelectrophoretic analysis of the allergens of Cynodon dactylon (Bermuda grass) pollen.

A crude extract of Cynodon dactylon (Bermuda grass) pollen was obtained by extraction, centrifugation, dialysis, and lyophilization. The corresponding polyspecific rabbit antibodies were obtained by immunization, bleeding, and purification and were used for a cross immunoelectrophoretic analysis of the crude extract. At least 52 antigens (Ags), of which 47 migrated toward the anode, and five, toward the cathode, were revealed. Crossed radioimmunoelectrophoretic analysis performed with sera from 32 patients allergic to Bermuda grass and a pool from 1000 normal individuals revealed specific IgE binding to 13 of these Ags. The approximate molecular weights (MWs) for 10 of these IgE-binding Ags were determined by a combination of gel filtration and immunochemical analysis. These Ags had apparent MWs greater than 14 kd. A combination of preparative sucrose gradient isoelectric focusing and immunochemical analysis was used to determine the approximate isoelectric point values of five of the IgE-binding Ags. Most precipitating Ags had isoelectric points between 4.5 and 5.5. Four of the Ags (Ag 24, MW, less than 65 kd; Ag 31, MW, 33 kd; Ag 33, MW, 20 kd; and Ag 34/35, MW, 32 kd) were classified as major allergens.