P25
Characterization and Solution Structure of non-specific Lipid Transfer Protein-2 from Rice
(Oryza sativa)
Y.J. Liu, D. Samuel, C.S. Cheng, C.H. Lin and P.C. Lyu*
Department of Life Sciences, National Tsing Hua University, Taiwan
A novel 7-kDa non-specific lipid transfer protein-2 (nsLTP2) has been isolated from rice ( Oryza sativa ) seeds.
The complete amino acid sequence was determined by N-terminal Edman degradation and trypsin fragmentation methods. This protein consists of 69 residues with eight conserved cysteines forming four disulfide bonds.
A lipid transfer activity of nsLTP2 is higher than nsLTP1. Chemical and thermal denaturation methods proved that nsLTP2 is more stable than nsLTP1. We also have been solved the three-dimensional structure of rice nsLTP2. The three-dimensional solution structure of rice nsLTP2 has a new fold with a triangular hydrophobic cavity formed by three prominent helices stabilized by four disulfide bonds. The disulfide bond pattern of nsLTP2 is different from nsLTP1. The positively charged residues on one face of LTP2 show structural similarity with other plant defense proteins.