Plant lipid transfer proteins

Plant lipid transfer proteins, also known as plant LTPs or PLTPs, are a group of highly-conserved proteins of about 9kDa found in higher plant tissues^[1]. As its name implies, lipid transfer proteins are responsible for the shuttling of phospholipids and other fatty acid groups between cell membranes^[2]. LTPs are also able to bind acyl groups^[2].

Other related proteins

Plant lipid transfer proteins share the same structural domain^[3] with seed storage proteins^[4] and trypsin-alpha amylase inhibitors^[5][6]. The domain forms a four-helical bundle in a right-handed superhelix with a folded leaf topology, which is stabilised by disulfide bonds, and which has an internal cavity.

There is no sequence similarity between animal and plant LTPs. In animals, cholesterylester transfer protein (CETP), also called plasma lipid transfer protein, is a plasma protein that facilitates the transport of cholesteryl esters and triglycerides between the lipoproteins.

Plant LTPs and human health

PLTPs are pan-allergens ^{[7] [8]}, and may be directly responsible for cases of food allergy. Pru p 3, the major allergen from peach, is a 9-kDa allergen belonging to the family of lipid-transfer proteins ^[9].

Commercial importance

Lipid transfer protein 1 (from barley) is responsible, when denatured by the mashing process, for the bulk of foam which forms on top of beer^[10].

See also

• Beer head

References