title: High-level production of lactostatin, a hypocholesterolemic peptide, in transgenic rice using soybean A1aB1b as carrier.
abstract: Hypercholesterolemia, a form of cardiovascular disease, is one of the leading causes of deaths worldwide. Lactostatin (Ile-Ile-Ala-Glu-Lys), derived from β-lactoglobulin in cow's milk, is a bioactive peptide with hypocholesterolemic activity higher than sitosterol, a known anti-hypercholesterolemic drug. Here, we successfully developed a transgenic rice accumulating a much higher level of lactostatin by inserting 29 IIAEK sequences into the structurally flexible (nonconserved) regions of soybean seed storage protein, A1aB1b, and introducing it into LGC-1 (low glutelin content mutant 1) as host variety. A1aB1b containing 29 lactostatins was expressed in the endosperm of rice seed cells by using seed specific promoters and sorted into novel compartments distinct from normal PB-I (ER-derived protein body) and PB-II (protein storage vacuoles). Transgenic rice seeds accumulated approximately 2 mg of lactostatins/g of dry seeds, which is relatively high compared with previous reports. Our findings suggest that the introduction of a high copy number of bioactive peptide into seed storage proteins as carrier is one of the effective means in producing higher amounts of bioactive peptides in rice.
authors.affiliation: Laboratory of Food Quality Design and Development, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
authors.forename: Cerrone
authors.initials: C
authors.lastname: Cabanos
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ekyo
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Amari
authors.forename: Naoki
authors.initials: N
authors.lastname: Kato
authors.forename: Masaharu
authors.initials: M
authors.lastname: Kuroda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nagaoka
authors.forename: Fumio
authors.initials: F
authors.lastname: Takaiwa
authors.forename: Shigeru
authors.initials: S
authors.lastname: Utsumi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Maruyama
mesh_terms: D000595:Amino Acid Sequence; D056625:Endosperm / Q000235:genetics / Q000378:metabolism; D005822:Genetic Vectors; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000096:biosynthesis* / Q000235:genetics; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D055314:Seed Storage Proteins / Q000235:genetics / Q000378:metabolism; D012995:Solubility; D030262:Soybean Proteins / Q000235:genetics* / Q000378:metabolism; D013025:Glycine max / Q000235:genetics*
chemical_list: D009842:Oligopeptides; D011994:Recombinant Proteins; D055314:Seed Storage Proteins; D030262:Soybean Proteins; C516979:lactostatin