<p>Plant cells contain proteins, called lipid transfer proteins (LTP) [<cite idref="PUB00027682"/>], which transfer phospholipids, glycolipids, fatty acids and sterols between lipid membranes [<cite idref="PUB00004991"/>]. The LTP family of proteins are thought to be involved in defence, pollination and germination. 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. LTP family members have been identified as major food allergens [<cite idref="PUB00027683"/>]. LTPs 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 TLPs, 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 TLPs are also similar to alpha-amylase inhibitor I2 from the seeds of Indian finger millet and amylase/protease inhibitors from rice and barley.</p><p>This entry represents the helical domain that forms the core of these proteins. Its structure consists of four helices in a right-handed superhelix with a folded leaf topology, which is stabilised by disulphide bonds. LTPs from different plants can show differences in their C-terminal tails and internal hydrophobic cavities, which may provide different lipid transfer properties [<cite idref="PUB00027659"/>].</p> Plant lipid transfer protein/hydrophobic protein, helical domain