InterPro domain: IPR033872

Plant nsLTPs are small, soluble proteins that facilitate the transfer of fatty acids, phospholipids, glycolipids, and steroids between membranes [ 1 ]. In addition to lipid transport and assembly, nsLTPs also play a key role in the defense of plants against pathogens [ 2 ]. There are two closely-related types of nsLTPs, types 1 and 2, which differ in protein sequence, molecular weight, and biological properties. nsLTPs contain an internal hydrophobic cavity, which serves as the binding site for lipids. Structure studies of rice nsLTPs show that the plasticity of the hydrophobic cavity is an important factor in ligand binding [ 3 ]. nsLTP2s possess a more flexible central hydrophobic cavity, resulting in increased lipid transfer activity [ 4 ]. The flexibility of the sLTP2 cavity allows its binding to rigid sterol molecules, whereas nsLTP1 cannot bind sterols despite its larger cavity size. The resulting nsLTP2/sterol complexes may bind to receptors that trigger defense responses [ 5 ]. The nsLTP2 of Brassica rapa has been identified as a potent allergen [ 5 , 6 ].

This entry represents the non-specific lipid-transfer protein type 2 (nsLTP2) family.

1. LIPID-TRANSFER PROTEINS IN PLANTS. Annu. Rev. Plant Physiol. Plant Mol. Biol. 47, 627-654
2. Binding mechanism of nonspecific lipid transfer proteins and their role in plant defense. Biochemistry 43, 13628-36
3. Solution structure of plant nonspecific lipid transfer protein-2 from rice (Oryza sativa). J. Biol. Chem. 277, 35267-73
4. Disulfide bond assignment, lipid transfer activity and secondary structure of a 7-kDa plant lipid transfer protein, LTP2. Eur. J. Biochem. 268, 1400-3
5. Molecular cloning of a cDNA encoding a pollen extracellular protein as a potential source of a pollen allergen in Brassica rapa. FEBS Lett. 424, 234-8
6. Nonspecific lipid-transfer proteins in plant foods and pollens: an important allergen class. Curr Opin Allergy Clin Immunol 5, 275-9