Proteomic and Genetic Approach for Lunasin Peptide and Gene Presence Detection in Various Plants

Lunasin is a biologically active peptide, with polypeptide chain consisting of 43 amino acids, originally discovered as a 2S albumin protein from the seed of the soybean coded by GM2S-1 gene. The first successful isolation of Lunasin peptide was performed at Niigata University School of Medicine in Japan in 1987 during the examination of protease inhibitors in soybean seeds. Subsequently, its presence was confirmed in cereal grains (wheat, barley, rye, triticale), in bean seeds and in other plants. The most significant health benefits include: antioxidant activity, anti-hypertension activity, chemoprevention activity, as well as its use as a therapeutic anticancer agent. It was also demonstrated that Lunasin exhibits anti-inflammatory activity, effects on lowering cholesterol and obesity as well as influence on immunodeficiency. However, Lunasin peptide was initially detected in many plant species, but there is controversy about its exact origins, in present. Therefore, we focused on detection of Lunasin gene by polymerase chain reaction and Lunasin peptide by one and two dimensional electrophoresis, in various plants. One dimensional electrophoresis separates plants proteins complexes only on molecular weight and hence, there were observed no significant evidence of Lunasin peptide presence or absence. Two dimensional electrophoresis provide exact separation and together with polymerase chain reaction enabled identification of Lunasin peptide and gene. These results confirmed, that Lunasin peptide as well as Lunasin gene were observed only in soy bean seeds. There were also confirmed presence of Lunasin peptide in various plants (Spelt wheat, bean and oat), but gene detection was not successful.