Grantee Research Project Results
2007 Progress Report: Risk Assessment of Food Allergenicity by a Data Base Approach
EPA Grant Number: R833137Title: Risk Assessment of Food Allergenicity by a Data Base Approach
Investigators: Braun, Werner , Goldblum, Randall M. , Midoro-Horiuti, Terumi , Schein, Catherine H. , Gendel, Steven
Current Investigators: Braun, Werner
Institution: The University of Texas Medical Branch - Galveston
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 2006 through September 30, 2009
Project Period Covered by this Report: October 1, 2006 through September 30,2007
Project Amount: $600,000
RFA: Biotechnology: Potential Allergenicity of Genetically Engineered Foods (2006) RFA Text | Recipients Lists
Research Category: Human Health
Objective:
Food allergies, mostly to milk, eggs, peanuts, soy or wheat, affect up to 8% of infants and young children, and can cause life-threatening reactions. Those children who maintain high levels of IgE antibodies to an allergen are less likely to outgrow their sensitivity and face a life of careful avoidance of all potential sources of the proteins that trigger their reactions. Because food allergies can result in fatal reactions, the allergenic potential of genetically engineered food products needs to be carefully assessed prior to their entry into the market. As the number and complexity of these bioengineered foods increase, the agency supports the development of scientific resources for determining potential allergenicity, including the availability of up-to-date bioinformatics tools to make such assessments. In our project, we will focus on the further development of our established bioinformatics tools to increase the specificity and sensitivity of these bioinformatics tools in predicting the allergenicity of food proteins. We also will study general structural requirements for an allergen by asking the question: What distinguishes an allergenic protein from a non-allergen?
Progress Summary:
Our SDAP Web server is an interactive website (http://fermi.utmb.edu/SDAP/ Exit ) that gives access to about 900 protein sequence entries as a relational data base. SDAP is the only publicly available Web database that can identify related segments in other allergenic proteins for given IgE epitopes. Recent improvements of the Web server in the reporting period include a comprehensive list of 3D models for the majority of SDAP entries, an enhanced analysis of the Pfam classification of allergens, and new graphics tools for representation of 3D structures. The user can download the coordinates of 3D models from our website and obtain a graphical representation by a choice of several graphical viewers, WebMol, Astex viewer and Chime. We also developed methods, unique to SDAP, to compare the physical-chemical properties of discrete areas of allergenic proteins to known IgE epitopes. We showed that by screening segments of allergens with low PD values we could detect related segments in allergens that had experimentally been shown to bind IgE. We now have expanded this work, to show that IgE binding correlates with PD values, as tested with designed peptide sequences. In complementary work, the allergens in SDAP have been classified to Pfam families, allowing us to identify sequence motifs characteristic of allergenicity. Those sequence motifs are publicly available on the MotifMate Web server (http://born.utmb.edu/motifmate/ Exit ). We also finished a large-scale modeling project to generate 3D models for a large majority of allergens. Of the 829 protein sequences archived in SDAP at this time, there are experimental structures for only 45 allergens. During the reporting period we obtained reliable 3D models for 433 allergens, including the major allergens of peanuts, tree nuts, weed and tree pollens, fungi and insects.
Future Activities:
Future activities include:
- mapping and analysis of IgE epitopes on our 3D models,
- further testing of the PD scale with food proteins, and
- use of sequence motifs for quantitative risk analysis.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 46 publications | 13 publications in selected types | All 13 journal articles |
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Schein CH, Ivanciuc O, Braun W. Bioinformatics approaches to classifying allergens and predicting cross-reactivity. Immunology and Allergy Clinics of North America 2007;27(1):1-27. |
R833137 (2007) R833137 (Final) |
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Supplemental Keywords:
relational database, large-scale 3D modeling of proteins, WHO/EFSA recommendations for risk assessment of proteins, Health, Scientific Discipline, Health Risk Assessment, Risk Assessments, Biology, Allergens/Asthma, Biochemistry, food allergenicity, data base development, dietary proteins, oral allergy syndrome, genetically engineered food, human exposure, bioinformatics, allergic responseRelevant Websites:
http://fermi.utmb.edu/SDAP/ Exit
http://born.utmb.edu/automotif/ Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.