Background: A principal aim of the safety assessment of genetically modified crops is to prevent the introduction of known or clinically cross-reactive allergens. Current bioinformatic tools and a database of allergens and gliadins were tested for the ability to identify potential allergens by analyzing 6 Bacillus thuringiensis insecticidal proteins, 3 common non-allergenic food proteins and 50 randomly selected corn (Zea mays) proteins. Methods: Protein sequences were compared to allergens using the FASTA algorithm and by searching for matches of 6, 7 or 8 contiguous identical amino acids. Results: No significant sequence similarities or matches of 8 contiguous amino acids were found with the B. thuringiensis or food proteins. Surprisingly, 41 of 50 corn proteins matched at least one allergen with 6 contiguous identical amino acids. Only 7 of 50 corn proteins matched an allergen with 8 contiguous identical amino acids. When assessed for overall structural similarity to allergens, these 7 plus 2 additional corn proteins shared ≧35% identity in an overlap of ≧80 amino acids, but only 6 of the 7 were similar across the length of the protein, or shared >50% identity to an allergen. Conclusions: An evaluation of a protein by the FASTA algorithm is the most predictive of a clinically relevant cross-reactive allergen. An additional search for matches of 8 amino acids may provide an added margin of safety when assessing the potential allergenicity of a protein, but a search with a 6-amino-acid window produces many random, irrelevant matches.

Keywords:
Allergen, Allergy, Bacillus thuringiensis, Bioinformatics, Biotechnology, Database, Food allergy, IgE epitope, Genetically modified crops
1.
Aronson AI, Shai Y: Why Bacillus thuringiensis insecticidal toxins are so effective: Unique features of their mode of action. FEMS Microbiol Lett 2001;195:1–8.
2.
McClintock JT, Schaffer CR, Sjoblad RD: A comparative review of the mammalian toxicity of Bacillus thuringiensis- based pesticides. Pestic Sci 1995;45:95–105.
3.
Siegel JP: The mammalian safety of Bacillus thuringiensis-based insecticides. J Invertebr Pathol 2001;77:13–21.
4.
EPA: EPA registration eligibility decision (RED) Bacillus thuringiensis. EPA 738-R-98–004 1998;March 1998.
5.
Betz FS, Hammond BG, Fuchs RL: Safety and advantages of Bacillus thuringiensis-protected plants to control insect pests. Regulatory Toxicol Pharmacol 2000;32:156–173.
6.
de Maagd RA, Bravo A, Crickmore N: How Bacillus thuringiensis has evolved specific toxins to colonize the insect world. Trends Genet 2001;17:193–199.
7.
Bravo A: Phylogenetic relationships of Bacillus thuringiensis delta-endotoxin family proteins and their functional domains. J Bacteriol 1997;179:2793–2801.
8.
Aalberse RC: Structural biology of allergens. J Allergy Clin Immunol 2000;106:228–238.
9.
Taylor SL, Hefle SL: Will genetically modified foods be allergenic? J Allergy Clin Immunol 2001;107:765–771.
10.
Gendel SM: The use of amino acid sequence alignments to assess potential allergenicity of proteins used in genetically modified foods. Adv Food Nutr Res 1998;42:45–62.
11.
Gendel SM: Sequence databases for assessing the potential allergenicity of proteins used in transgenic foods. Adv Food Nutr Res 1998;42:63–92.
12.
Astwood JD, Fuchs RL: Allergenicity of foods derived from transgenic plants. Monogr Allergy 1996;32:105–120.
13.
Metcalfe DD, Astwood JD, Townsend R, Sampson HA, Taylor SL, Fuchs RL: Assessment of the allergenic potential of foods derived from genetically engineered crop plants. Crit Rev Food Sci Nutr 1996;36:S165–186.
14.
Taylor SL, Hefle SL, Gauger BJ: Food allergies and sensitivities; in Helferich W, Winter CK (eds): Food Toxicology. New York, CRC Press, 2000, pp 1–36.
15.
Plant M, Zimmerman EM: Allergy and mechanisms of hypersensitivity; in Paul WE (ed): Fundamental Immunology. New York, Raven Press, 1993, pp 1399–1425.
16.
Berzofsky JA, Berkower IJ, Epstein SL: Antigen-antibody interactions and monoclonal antibodies; in Paul WE (ed): Fundamental Immunology. New York, Raven Press, 1993, pp 421–465.
17.
Scheurer S, Wangorsch A, Nerkamp J, Skov PS, Ballmer-Weber B, Wuthrich B, Haustein D, Vieths S: Cross-reactivity within the profiling panallergen family investigated by comparison of recombinant profilins from pear (Pyr c 4), cherry (Pru av 4) and celery (Api g 4) with birch pollen profiling Bet v 2. J Chromatogr B 2001;756:315–325.
18.
Aalberse RC, Akkerdaas J, van Ree R: Cross-reactivity of IgE antibodies to allergens. Allergy 2001;56:478–490.
19.
Pearson WR: Flexible sequence similarity searching with the FASTA3 program package. Methods Mol Biol 2000;132:185–219.
20.
Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ: Basic local alignment search tool. J. Mol Biol 1990;215:403–410.
21.
Beezhold DH, Hickey VL, Slater JE, Sussman GL: Human IgE-binding epitopes of the latex allergen Hev b 5. J Allergy Clin Immunol 1999;103:1166–1172.
22.
Banerjee B, Greenberger PA, Fink JN, Kurup VP: Conformational and linear B-cell epitopes of Asp f 2, a major allergen of Aspergillus fumigatus, bind differently to immunoglobulin E antibody in the sera of allergic bronchopulmonary aspergillosis patients. Infect Immun 1999;67:2284–2291.
23.
Chatchatee P, Jarvinen KM, Bardina L, Beyer K, Sampson HA: Identification of IgE- and IgG-binding epitopes on alpha(s1)-casein: Differences in patients with persistent and transient cow’s milk allergy. J. Allergy Clin Immunol 2001;107:379–383.
24.
Rabjohn P, Helm EM, Stanley JS, West CM, Sampson HA, Burks AW, Bannon GA: Molecular cloning and epitope analysis of the peanut allergen Ara h 3. J Clin Invest 1999;103:535–542.
25.
Bredehorst R, David K: What establishes a protein as an allergen? J Chromatogr B Biomed Sci Appl 2001;756:33–40.
26.
Ferguson A: Gluten-sensitive enteropathy (celiac disease); in Metcalfe DD, Sampson HA, Simon RA (eds): Food Allergy: Adverse Reactions to Foods and Food Additives. Cambridge, Blackwell Science, 1996, pp 287–301.
27.
FAO/WHO expert consultation: Evaluation of allergenicity of genetically modified foods, Rome, Jan, 2001. http://www.who.int/fsf/Gmfood/Consultation-Jan2001/report20.pdf.
28.
Pastorello EA, Farioli L, Pravettoni V, Ispano M, Scibola E, Trambaioli C, Giuffrida MG, Ansaloni R, Godovac-Zimmermann J, Conti A, Fortunato D, Ortolani C: The maize major allergen, which is responsible for food-induced allergic reactions, is a lipid transfer protein. J Allergy Clin Immunol 2000;106:744–751.
29.
Benson DA, Boguski MS, Lipman DJ, Ostell J: GenBank. Nucl Acids Res 1997;25:1–6.
30.
George DG, Dodson RJ, Garavelli JS, Haft DH, Hunt LT, Marzec CR, Orcutt BC, Sidman KE, Srinivasarao GY, Yeh LSL, Arminski LM, Ledley RS, Tsugita A, Barker WC: The Protein Information Resource (PIR) and the PIR-International Protein Sequence Database. Nucleic Acids Res 1997;25:24–28.
31.
Berman HM, Westbrook J, Feng Z, Gilliland G, Bhat TN, Weissig H, Shindyalov IN, Bourne PE: The Protein Data Bank. Nucleic Acids Res 2000;28:235–242.
32.
Bernstein FC, Koetzle TF, Williams GJ, Meyer EF Jr, Brice MD, Rodgers JR, Kennard O, Shimanouchi T, Tasumi M: The Protein Data Bank. A computer-based archival file for macromolecular structures. Eur J Biochem 1977;80:319–324.
33.
Bairoch A, Apweiler R: The SWISS-PROT protein sequence data bank and its supplement TrEMBL. Nucleic Acids Res 1997;25:31–36.
34.
Schuler GD, Epstein JA, Ohkawa H, Kans JA: Entrez: Molecular biology database and retrieval system. Methods Enzymol 1996;266:141–162.
35.
Pearson WR, Lipman DJ: Improved tools for biological comparison. Proc Natl Acad Sci USA 1988;85:2440–2448.
36.
Lipman DJ, Pearson WR: Rapid and sensitive protein similarity searches. Science 1985;227:1435–1441.
37.
Henikoff S, Henikoff JG: Amino acid substitution matrices from protein blocks. Proc Natl Acad Sci USA 1992;89:10915–10919.
38.
Henikoff JG, Henikoff S: Blocks database and its applications. Methods Enzymol 1996;266:88–105.
39.
Doolittle RF: Searching through sequence databases. Methods Enzymol 1990;183:99–110.
40.
Pearson WR: Effective protein sequence comparison. Methods Enzymol 1996;266:227–258.
41.
Buse G, Steffens GJ, Braunitzer G, Steer W: Hemoglobins. XXV. Hemoglobin (erythrocruorin) CTT III from Chironomus thummi thummi (Diptera). Primary structure and relationship to other heme proteins (author’s transl)]. Hoppe Seylers Z Physiol Chem 1979;360:89–97.
42.
Hemmann S, Menz G, Ismail C, Blaser K, Crameri R: Skin test reactivity to 2 recombinant Aspergillus fumigatus allergens in A. fumigatus- sentitized asthmatic subjects allows diagnostic separation of allergic bronchopulmonary aspergillosis from fungal sensitization. J Allergy Clin Immunol 1999;104:601–607.
43.
Broadwater AH, Rubinstein AL, Chay CH, Klapper DG, Bedinger PA: Zea mI, the maize homolog of the allergen-encoding Lol pI gene of rye grass. Gene 1993;131:227–230.
44.
Reeck GR, de Haen C, Teller DC, Doolittle RF, Fitch WM, Dickerson RE, Chambon P, McLachlan AD, Margoliash E, Jukes TH, Zuckerkandl E: ‘Homology’ in proteins and nucleic acids: A terminology muddle and a way out of it. Cell 1987;50:667.
45.
Baxevanis, AD, Ouellette BFF (eds): Bioinformatics: A Practical Guide to the Analysis of Genes and Proteins. Methods of Biochemical Analysis.. New York, Wiley, 1998, vol 39.
46.
Reese G, Ayuso R, Lehrer SB: Tropomyosin: An invertebrate pan-allergen. Int Arch Allergy Immunol 1999;119:247–258.
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