Plant cells contain proteins, called lipid transfer proteins (LTP), which transfer phospholipids, glycolipids, fatty acids and sterols from liposomes or microsomes to mitochondria. These proteins, whose subcellular location is not yet known, could play a major role in membrane biogenesis by conveying phospholipids such as waxes or cutin from their site of biosynthesis to membranes unable to form these lipids. PLTPs exist in animal and plant tissues, including rat liver cytosol, potato tuber, castor bean, maize seedlings, spinach, barley and wheat. While there is no sequence similarity between animal and plant PTLPs, similarity between the Plant proteins is high. Plant LTP's are proteins of about 9 Kd (90 amino acids), containing eight conserved cysteine residues which form 4 disulphide bridges. Plant PTLPs are also similar to alpha-amylase inhibitor I2 from the seeds of Indian finger millet and amylase/protease inhibitors from rice and barley.Some of the proteins in this family 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. A nomenclature system has been established for antigens (allergens) that cause IgE-mediated atopic allergies in humans [WHO/IUIS Allergen Nomenclature Subcommittee King T.P., Hoffmann D., Loewenstein H., Marsh D.G., Platts-Mills T.A.E., Thomas W. Bull. World Health Organ. 72:797-806(1994)]. This nomenclature system is defined by a designation that is composed ofthe first three letters of the genus; a space; the first letter of thespecies name; a space and an arabic number. In the event that two speciesnames have identical designations, they are discriminated from one anotherby adding one or more letters (as necessary) to each species designation. The allergens in this family include allergens with the following designations: Par j 1 and Par j 2.