Lipid transfer proteins

Widespread compact, phylogenetically strongly preserved, vegetable, heat and acid stable (no degradation by gastroenterological digestive enzymes) protein family (panallergens). Lipid transfer proteins are divided into 2 subfamilies:

• LTP1 (9-10kDa)
• and
• LTP2 (6-7kDa).

All known as allergenic lipid transfer proteins belong to the subfamily LTP1.

Lipid transfer proteins (LTPs) have a function in the cytoplasmic transport of lipids (lipid transfer), as well as in the formation of the waxy cuticle on the outer layer of the leaves (cuticle). They are also involved in the defence against biotic (bacteria, fungi) and abiotic (cold, drought) stressors. They have been assigned as PR-14 proteins (PR: "pathogenesis-related") to the plant stress proteins (Peterson A, 2015). Adapted to their function, PR proteins are generally resistant to heat, acids and proteases, so that the frequency of systemic reactions (in >35% of cases) can be explained (Vanstreels L et al. 2014).

Note: the LTP-containing Pru p 3 of the peach is 7 times more concentrated in the skin than in the pulp.

Lipid transfer proteins (LTP) are the major allergens in patients who develop sensitization to fruits of the rosacea family (Mal d 3: apple, apricot, Pru av 3: cherry, plum and peach) and others (e.g. Vit v 1: grape, Cor a 8: hazelnut), but who are not allergic to birch pollen.

Lipid transfer proteins cause e.g. severe reactions ( cross-reaction) after fruit and vegetable consumption, e.g. through a primary gastrointestinal sensitization by Pru p3, the major allergen of peaches.

The name results from its originally assumed function of transporting phospholipids from the ribosomes to the mitochondria.

1. Asero et al (2001) Allergy to nonspecific lipid transfer proteins in Rosaceae: a comparative study of different in vivo diagnostic methods. Ann Allergy Asthma Immunol 87: 68-71
2. Gebhardt et al (2009) 10 kDa lipid transfer protein: the main allergenic structure in a German patient with anaphylaxis to blueberry. Allergy 64: 498-49
3. Petersen A et al (2015) Stable plant food allergens I: Lipid transfer proteins. In: Kleine-Tebbe J et al. Hrsg Molecular allergy diagnostics. Springer Publishing House Berlin-Heidelberg S 45-59
4. Romano et al (2009) Allergy to peanut lipid transfer protein (LTP): frequency and cross-reactivity between peanut and peach LTP. Eur Ann Allergy Clin Immunol 41: 106 -111
5. Vanstreels L et al (2014) Double sensitization to PR10 and PR-14 proteins. Dermatologist 65:1017-1018.