Peptide mapping of the major components of in vitro synthesized barley hordein: Evidence of structural homology

Abstract

Membrane bound polysomes from Bomi barley endosperm were used as a template for in vitro hordein synthesis. The (35S)-methionine-labelled hordein was isolated by extraction with 55% isopropanol and the individual component polypeptides were resolved by SDS-polyacrylamide gel electrophoresis with detection by autoradiography. Eight bands in the molecular weight range 28,000 to 67,000 were excised from the gel. Treatment of the gel slices with chymotrypsin released soluble peptide products from the polypeptides. The resultant peptides were analysed by two dimensional thin layer chromatography and autoradiography of the (35S)-methionine-containing peptides. The peptide maps had a number of features in common, suggesting a primary structural homology between the different polypeptides.