Separation of acidic barley endosperm proteins by two-dimensional electrophoresis

Proteins in barley aleurone and starchy endosperm from developing seeds were separated by two-dimensional (2-D) electrophoresis according to O'Farrell's method. The effect of different extraction methods on the separation was compared. The two best extraction methods were compared by amino acid analysis of extracts and residues. Some tissue-specific proteins in both tissues are described. Different methods for transfer of separated proteins onto membranes were compared. Amino terminal and internal sequences were determined after transfer of separated proteins or their proteolytic products onto membranes. Amino acid sequence data allowed the identification of 12 different proteins, while 6 remain unidentified and 8 appeared to have a blocked amino terminal.