title: In vitro synthesis of barley storage proteins.
abstract: Membrane-bound polysomes were isolated from developing endosperms of barley (Hordeum vulgare L.) and shown to support the synthesis of trichloroacetic acid-insoluble material by an in vitro wheat germ protein synthesis system. The mRNA associated with the polysomes was separated from the ribosomes by affinity chromatography on oligo-dT cellulose and was also shown to support in vitro protein synthesis. The poly-A(+) RNA isolated contained material of between 0.55 and 2.55 kilobases in length with about 6% poly A. The products of in vitro protein synthesis resembled hordeins (the prolamin storage proteins of the barley endosperm) in that they were predominantly soluble in 55% propan-2-ol, contained a low proportion of lysine as compared with leucine and had similar, but not identical, electrophoretic properties. The differences in the electrophoretic behaviour between the products of poly-A(+) RNA translation and authentic hordeins is suggested to be due to the presence of an extra (leader?) sequence on the former.
authors.affiliation: Biochemistry Department, Rothamsted Experimental Station, AL5 2JQ, Harpenden, Herts., UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Matthews
authors.forename: B J
authors.initials: BJ
authors.lastname: Miflin