Isolation and characterization of thirteen new salt-soluble proteins from barley by reversed-phase high-performance liquid chromatography

Abstract

Thirteen new proteins from barley (Hordeum vulgare L.) have been isolated and characterized. These proteins and seven other previously known components were isolated from a 0.5-M NaCl extract of endosperm by single-step, reversed-phase, high-performance liquid chromatography, using a Vydac C₄ semi-preparative column. The purity of the isolated proteins was analyzed by polyacrylamide gel electrophoresis at pH 3.2 or in sodium dodecyl sulfate, by two-dimensional gel electrophoresis and was further confirmed by partial NH₂-terminal sequencing. The NH₂-terminal amino-acid sequences of fourteen of the components were determined, from 5 to 27 cycles, by automated liquid-phase sequencing. According to the sequence data and predictions of secondary structure, different groups of homologous proteins were established. Based on the presented results, two thionins, one trypsin inhibitor and one α-amylase/subtilisin inhibitor are included among the purified proteins.