Lipid transfer proteins and 2S albumins as allergens

Plant lipid transfer proteins, a widespread family of proteins, have been r ecently identified as important food allergens. Their common structural fea tures, such as eight conserved cysteines forming disulfide bridges, basic i soelectric point and high similarity in amino acid sequence, are the basis of allergic clinical crossreactivity. This has been demonstrated for the LT P allergens of the Prunoideae subfamily, whose similarity is about 95% as d emonstrated for the purified allergens of peach, apricot, plum and apple. A relevant aspect is the existence of sequence homology of LTPs of botanical ly unrelated foods, as demonstrated for LTPs of maize and peach. A class of food allergens of well recognized clinical importance is that of seed stor age 2S albumins. They have been identified in the most diffused edible seed s and nuts, such as mustard, sesame, Brazil nut, walnut and peanut. In part icular, a strong correlation between IgE-binding to these proteins and food -induced anaphylaxis has been demonstrated for Brazil nut and sesame seeds.