Lunasin Peptide

Lunasin, a cancer fighting peptide Lunasin, a natural killer cell activating peptide, is a novel peptide found in the soybean 2S albumin seed protein. Lunasin also found in barley, wheat, and rye. The peptide has both anticancer and anti-inflammatory activities. Lunasin was originally isolated from the soybean cotyledon, the seed leaf, and because of its properties this peptide was termed lunasin from the Tagalog word “lunas” for cure. Lunasin contains 43 amino acid residues having a unique sequence that includes the cell adhesion motif RGD and a carboxylic acid tail composed of nine aspartic acid residues. Its sequence is SKWQHQQDSC RKQKQGVNLT PCEKHIMEKI QGRGDDDDDDD DD. Peptides containing the RGD motif have been reported to prevent metastasis of tumor cells by competitive adhesion to extracellular matrices. Various studies showed that lunasin suppresses both chemical and oncogene driven transformation of mammalian cells. The peptide acts as a chemopreventive agent by suppressing cell transformation and subsequent carcinogenesis. The treatment of different mammalian cells with synthetic lunasin showed preferential adherence of this peptide to chromatin, leading to disruption of the kinetochore and inhibition of mitosis. This activity appears to be due to the binding of its negatively charged poly-D carboxyl end to the highly basic histones found within the nucleosomes of condensed chromosomes. It is thought that lunasin binds to regions that are more positively charged, such as the core histones in chromatin regions found in telomeres and centromeres. This binding is facilitated by the poly-aspartyl end of the peptide. The amino acid region 23 to 31 targets lunasin to chromatin.