title: Scalable purification and characterization of the anticancer lunasin peptide from soybean.
abstract: Lunasin is a peptide derived from the soybean 2S albumin seed protein that has both anticancer and anti-inflammatory activities. Large-scale animal studies and human clinical trials to determine the efficacy of lunasin in vivo have been hampered by the cost of synthetic lunasin and the lack of a method for obtaining gram quantities of highly purified lunasin from plant sources. The goal of this study was to develop a large-scale method to generate highly purified lunasin from defatted soy flour. A scalable method was developed that utilizes the sequential application of anion-exchange chromatography, ultrafiltration, and reversed-phase chromatography. This method generates lunasin preparations of >99% purity with a yield of 442 mg/kg defatted soy flour. Mass spectrometry of the purified lunasin revealed that the peptide is 44 amino acids in length and represents the original published sequence of lunasin with an additional C-terminal asparagine residue. Histone-binding assays demonstrated that the biological activity of the purified lunasin was similar to that of synthetic lunasin. This study provides a robust method for purifying commercial-scale quantities of biologically-active lunasin and clearly identifies the predominant form of lunasin in soy flour. This method will greatly facilitate the development of lunasin as a potential nutraceutical or therapeutic anticancer agent.
authors.affiliation: James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Seber
authors.forename: Brian W
authors.initials: BW
authors.lastname: Barnett
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: McConnell
authors.forename: Steven D
authors.initials: SD
authors.lastname: Hume
authors.forename: Jian
authors.initials: J
authors.lastname: Cai
authors.forename: Kati
authors.initials: K
authors.lastname: Boles
authors.forename: Keith R
authors.initials: KR
authors.lastname: Davis
mesh_terms: D000970:Antineoplastic Agents; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006657:Histones / Q000378:metabolism; D006801:Humans; D010455:Peptides / Q000302:isolation & purification* / Q000378:metabolism*; D011485:Protein Binding; D030262:Soybean Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D013025:Glycine max / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D000970:Antineoplastic Agents; C120514:GM2S-1 protein, soybean; D006657:Histones; D010455:Peptides; D030262:Soybean Proteins