Bet v I allergen

Bet v I/Major latex protein is a protein family consisting of proteins from plants.

Some members are allergens. Allergies are hypersensitivity reactions of the immune system to specific substances called allergens (such as pollen, stings, drugs, or food) that, in most people, result in no symptoms. Trees within the order Fagales possess particularly potent allergens, e.g. the prototypical Bet v 1, the major white birch (Betula verrucosa - now called B. pendula) pollen antigen. Bet v 1 is the main cause of type I allergies observed in early spring. Type I, or immunoglobulin E-mediated (IgE-mediated) allergies affect 1 in 5 people in Europe and North America. Commonly observed symptoms are hay fever, dermatitis, asthma and, in severe cases, anaphylactic shock. First contact with these allergens results in sensitisation; subsequent contact produces a cross-linking reaction of IgE on mast cells and concomitant release of histamine. The inevitable symptoms of an allergic reaction ensue.

The motif (matching the signatures of IPR000916) is also found in non-allergens such as:

• The pathogenesis-related proteins (PRs) of the PR10 family, including:
  • the wound-induced protein AoPR1 from Asparagus officinalis (Garden asparagus);
  • the PRs from Phaseolus vulgaris (Kidney bean) and Petroselinum crispum (Parsley) (PR1-1 and PR1-3);
  • the disease resistance response proteins, STH-2 and STH-21, from Solanum tuberosum (Potato) and pI49, pI176 and DRRG49-C from Pisum sativum (Garden pea);
  • the P. sativum abscisic acid-responsive proteins ABR17 and ABR18;
  • and the stress-induced protein SAM22 from Glycine max (Soybean).
• The legume cytokinin-binding proteins;
• The (S)-norcoclaurine synthase, key to the synthesis of alkaloids such as morphine;
• The major latex proteins and other ripening-related proteins, originally discovered in the opium poppy.

Additionally, the core domain of Bet v 1 founds or is part of a superfamily of domains called SRPBCC (START/RHOalphaC/PITP/Bet v1/CoxG/CalC) that include the StAR-related transfer domain (START), a domain found in humans. This superfamily shares a similar structure and all have large pocket, presumably for binding hydrophobic molecules.