Apple Allergy: The cDNA Sequence of the Major Allergen of Apple, Determined by Performing PCR with a Primer Based on theN-Terminal Amino Acid Sequence, is Highly Homologous to the Sequence of the Major Birch Pollen Allergen
✍ Scribed by Schöning, Britta; Ziegler, Wolfgang H; Vieths, Stefan; Baltes, Werner
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 748 KB
- Volume
- 71
- Category
- Article
- ISSN
- 0022-5142
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✦ Synopsis
Considering the known N-terminal amino acid sequence of the major apple allergen, a polymerase chain reaction (PCR) primer was selected to amplify cDNA encoding this protein. A single PCR product was obtained, cloned into Escherichia coli and subsequently sequenced. The missing 5'-end of the apple cDNA sequence was obtained by a 5'-RACE method. The cDNA sequence showed 72% identity with the coding region of one of the known isoforms of Bet v 1, the major allergen of birch pollen. The deduced amino acid sequence resulted in a 158-residue protein with a calculated molecular mass of 17.5 kDa and 63% amino acid sequence identity to Bet v 1. In addition, further protein alignments showed a high degree of identity with allergens from other tree pollens and some 'pathogenesis-related proteins' from food plants. According to international regulations the allergen was termed Ma1 d 1 for this protein, it being the first major allergen discovered and characterised in fruits of apple (Malus dornestica).