Characterization of Major Proteins and Peptides in Beer. S. Yokoi and A. Tsugita, Department of Chemistry, Science University of Tokyo, Noda, Japan 278, and K. Kamada, Research & Development Laboratories, Sapporo Breweries Ltd., Yaizu, Shizuoka, Japan 425. J. Am. Soc. Brew. Chem. 46:0099, 1988.

Proteins and peptides in beer were characterized with sodium dodecyl sulfate gel electrophoresis and high-performance liquid chromatography, respectively. Three major proteins-40, 10, and 8 kilodaltons (kDa)-and several peptides are described. The 40-kDa protein is derived from the barley Protein Z, as judged from the amino acid composition. The 10- and 8-kDa proteins are similar to each other in both amino acid compositions and carboxy-terminal amino acid sequences. The 10-kDa protein comes directly from barley, whereas the 8-kDa protein is derived from the 10-kDa protein by degradation in the N-terminal region. The amino acid compositions of some peptides in beer are summarized.

Keywords: Amino acid composition, Barley, Electrophoresis, HPLC, Partial amino acid sequence