Isolation and partial characterization of Bermuda grass-pollen allergen: BG-60b.

Our earlier studies have shown that the pollen of Bermuda grass (Cynodon dactylon)-pollen contain at least 12 IgE-binding proteins which can be analyzed by the immunoblot technique. One of the highly active components was found to be a basic protein with a molecular weight of 60,000 daltons, designated as BG-60. This component was showed to consist of a group of proteins. One of them, BG-60a (pI 9.7), has been isolated and characterized. In this study, we have further isolated and characterized the second component of the antigen, designated as BG-60b. Its purity was demonstrated by gel electrophoresis experiment and antigen-antibody precipitation studies. The antigen is of glycoprotein nature with a pI of 10.0. It exhibits IgE-binding activity and shows cross-reactivity to antigen BG-60a in double diffusion. Its chemical and physical properties are similar to antigen BG-60a.