Crystal structure of timothy grass allergen Phl p 12.0101 reveals an unusual profilin dimer

Andrea O’Malley; A. Brenda Kapingidza; Noah Hyduke; Coleman Dolamore; Krzysztof Kowal; Maksymilian Chruszcz

doi:10.18388/abp.2020_5587

Andrea O’Malley Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
A. Brenda Kapingidza Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
Noah Hyduke Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
Coleman Dolamore Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
Krzysztof Kowal 1Department of Allergology and Internal Medicine, Medical University of Bialystok, Bialystok 15-276, Poland; 2Department of Experimental Allergology and Immunology, Medical University of Bialystok, Bialystok 15-276, Poland
Maksymilian Chruszcz Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA

DOI: https://doi.org/10.18388/abp.2020_5587

Abstract

Timothy grass pollen is a source of potent allergens. Among them, Phl p 1 and Phl p 5 are thought to be the most important, as a majority of timothy grass-allergic individuals have IgE antibodies directed against these two allergens. The profilin from timothy grass (Phl p 12) has been registered as a minor allergen, with up to 35% of individuals in populations of grass pollen allergic patients showing IgE binding to Phl p 12. Profilins are primarily minor allergens and are known for a high likelihood of co-sensitization as well as cross-reactivity situations caused by their sequence and structure similarity. The crystal structure of Phl p 12.0101 was determined and it revealed that this allergen may form an unusual dimer not previously observed among any profilins. For example, the Phl p 12 dimer has a completely different geometry and interface when compared with the latex profilin (Hev b 8) dimer that has its crystal structure determined. The structure of Phl p 12.0101 is described in the context of allergenic sensitization and allergy diagnostics. Moreover, the structure of the Phl p 12.0101 dimer is discussed, taking into account the production of recombinant allergens and their storage.