Barley Lunasin Suppresses ras-Induced Colony Formation and Inhibits Core Histone Acetylation in Mammalian Cells

Abstract

Lunasin is a novel peptide originally identified in soybean that suppresses chemical carcinogen-induced transformation in mammalian cells and skin carcinogenesis in mice. Since the lunasin gene was cloned from soybean and the chemically synthesized form of the lunasin peptide has been used in experiments conducted so far, the isolation of lunasin from other natural sources and testing of its biological properties have not been carried out. We report here the isolation, purification, and biological assay of lunasin from barley, a newly found rich source of the peptide. The identity of lunasin was established by Western blot analysis and mass spectrometric peptide mapping of the in-gel tryptic digest of the putative protein band. Lunasin was partially purified with anion exchange and immunoaffinity chromatography. The crude and partially purified lunasin from barley suppressed colony formation in stably ras-transfected mouse fibroblast cells induced with IPTG. These fractions also inhibited histone acetylation in mouse fibroblast NIH 3T3 and human breast MCF-7 cells in the presence of the histone deacetylase inhibitor sodium butyrate.

A Review of Extraction and Analysis of Bioactives in Oat and Barley and Scope for Use of Novel Food Processing Technologies

“…However, lunasin a novel 4.8 kDa cancer preventive seed-peptide, has been reported to be prevalent in barley [89]. Lunasin enriched barley (LEB) was obtained by extracting barley flour with phosphate-buffered saline supplemented with protease inhibitor cocktail for 48 h at 4 °C.…”

“…Alkaline extraction using NaOH and addition of HCl at pH 4.6 for precipitation of protein [105]; A peptide lunasin has been isolated from barley with phosphate-buffered saline supplemented with protease inhibitor cocktail, followed by column and immunoaffinity chromatography [89].…”

Lunasin: A promising polypeptide for the prevention and treatment of cancer

“…This extraction method usually results in a crude protein containing lunasin, which requires further purification. Ion-exchange column chromatography has been used for the purification of lunasin extracted from soybean and barley in previous studies, and the principal material used in the ion-exchange column is bio-gel resin AG1-X4 with a particle size of between 100 and 200 mesh, and the volume of the ion-exchange column is 5.0x50 cm with a filled height of 40 cm (27,28). In addition, gel electrophoresis, western blotting and mass spectrometry are also used for the qualitative analysis and quantitative determination of lunasin (29,30).…”

Beneficial Effects of Bioactive Peptides Derived from Soybean on Human Health and Their Production by Genetic Engineering

“…The purification of lunasin from plant sources is tedious. To date, lunasin has been isolated from various plants such as soybean (Odani et al, 1987b), barley (Jeong et al, 2002), herbs (Solanum nigrum L.; Jeong et al, 2007a), wheat (Jeong et al, 2007b), and amaranth (Amaranthus hypochondriacus; Silva-Sanchez et al, 2008). Natural lunasin has been extracted and purified by ion exchange chromatography and immuno-affinity column chromatography.…”

“…Commercial soy products contain reasonable amounts of lunasin, ranging from 5.48 mg of lunasin per gram of protein (defatted soy flour) to 16.52 mg of lunasin per gram of protein (soy concentrate) (Jeong et al, 2003). The lunasin content of extracts from different varieties of barley ranges from 5.93 to 8.71 mg of lunasin per gram of protein (Jeong et al, 2002) and 36.4 mg of lunasin per gram of protein in Solanum nigrum L extract (Jeong et al, 2007a). Wheat and amaranth extracts have 3.95-17.2 mg lunasin per gram of protein (Jeong et al, 2007b) and 11.1 μg lunasin per gram of protein (Silva-Sanchez et al, 2008), respectively.…”