Analysis of the three-dimensional antigenic structure of giant ragweed allergen, Amb t 5

Thorunn Rafnar, Mary E. Brummet, Donna Bassolino-Klimas, William J. Metzler, David G. Marsh

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


The ragweed allergens Amb t 5 and Amb a 5 are among the smallest inhaled protein allergens known, containing a single, immunodominant T-cell epitope. In this study we analyzed the B-cell epitope structure of Amb t 5. The three- dimensional structures of Amb t 5 and Amb a 5 have been determined by NMR spectroscopy, providing a rare opportunity to analyze three-dimensional antigenic sites. Amb t 5 residues likely to be important for antigenicity were identified by examining the surface area of Amb t 5 accessible to a probe of the size of an antibody molecule. After changing these residues to the corresponding Amb a 5 residues, recombinant proteins were purified and tested for loss of antigenic activity. Inhibition radio-immunoassays, using sera from 8 individuals who had received immunotherapy with giant ragweed extract, allowed the mutations to be divided into three groups: (1). mutations that had little or no effect on antibody binding, (2) mutations that caused a loss of antigenic activity to a different degree in different sera and (3) mutations that drastically reduced antigenic activity in all sera tested. This last set of mutations clustered in the third loop of Amb t 5, suggesting that antibody recognition of Amb t 5, like T-cell recognition, is primarily directed towards a single, immunodominant site.

Original languageEnglish (US)
Pages (from-to)459-467
Number of pages9
JournalMolecular Immunology
Issue number8
StatePublished - May 1 1998
Externally publishedYes


  • Allergens
  • Epitope structure
  • Ragweed

ASJC Scopus subject areas

  • Immunology
  • Molecular Biology


Dive into the research topics of 'Analysis of the three-dimensional antigenic structure of giant ragweed allergen, Amb t 5'. Together they form a unique fingerprint.

Cite this