title: Changes in lipid metabolism by soy beta-conglycinin-derived peptides in HepG2 cells.
abstract: In this study, HepG2 cells were treated with short peptides (7S-peptides) derived from highly purified soybean beta-conglycinin (7S), which was free from lipophilic protein, and the effect of the peptide treatment on lipid metabolism was determined. 7S-peptide treatment suppressed the secretion of apolipoprotein B-100 from HepG2 cells into the medium. The 7S-peptides also suppressed the incorporation of (3)H-glycerol and (14)C-acetate into triacylglyceride but not into major phospholipids, such as phosphatidylcholine and phosphatidylethanolamine. Additionally, the synthesis of cholesterol esters was dramatically decreased for 2 h after the addition of the 7S-peptides, whereas the synthesis of cholesterol remained unchanged by 4 h and increased by 8 h after the addition of the 7S-peptides. The cleaved nuclear form of SREBP-2 increased 8 h after the addition of the 7S peptides, suggesting a decrease in intracellular cholesterol levels. Analysis of changes in mRNA expression after 7S-peptide treatment suggested that the 7S-peptides lower the level of cholesterol in the endoplasmic reticulum, increase the mRNA of genes related to beta-oxidation of fatty acids, and increase the synthesis of cholesterol. From these results, it may be concluded that the peptides derived from 7S altered the lipid metabolism to decrease secretion of apolipoprotein B-100-containing lipoprotein from HepG2 cells.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, and Uji, Kyoto 611-0011, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Mochizuki
authors.forename: Motohiro
authors.initials: M
authors.lastname: Maebuchi
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Kohno
authors.forename: Motohiko
authors.initials: M
authors.lastname: Hirotsuka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Wadahama
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Moriyama
authors.forename: Teruo
authors.initials: T
authors.lastname: Kawada
authors.forename: Reiko
authors.initials: R
authors.lastname: Urade
mesh_terms: D052179:Antigens, Plant; D053299:Apolipoprotein B-100 / Q000032:analysis / Q000378:metabolism; D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D005916:Globulins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D050356:Lipid Metabolism / Q000187:drug effects*; D008074:Lipoproteins / Q000737:chemistry / Q000378:metabolism; D008113:Liver Neoplasms; D010447:Peptide Hydrolases / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology*; D055314:Seed Storage Proteins / Q000737:chemistry* / Q000378:metabolism; D030262:Soybean Proteins / Q000737:chemistry* / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry*; D014280:Triglycerides / Q000096:biosynthesis
chemical_list: D052179:Antigens, Plant; D053299:Apolipoprotein B-100; D005916:Globulins; D008074:Lipoproteins; D010455:Peptides; D055314:Seed Storage Proteins; D030262:Soybean Proteins; D014280:Triglycerides; C013894:beta-conglycinin protein, Glycine max; D010447:Peptide Hydrolases