VIEW ARTICLE    DOI: 10.1094/ASBCJ-41-0120

Heterogeneity of the β-Amylase Enzymes of Barley. D. E. LaBerge and B. A. Marchylo, Grain Research Laboratory, Canadian Grain Commission, Winnipeg, Manitoba, Canada R3C 3G8. J. Am. Soc. Brew. Chem. 41:0120, 1983.

Eight major and several minor β-amylase components were separated reproducibly by chromatofocusing of thiol-containing extracts of barley. Each of these components had distinctive apparent pI values. During rechromatofocusing, each major component eluted reproducibly with the same apparent pI value but additionally produced one or several β-amylase components with apparent pI values similar to other major β-amylase components. Similar molecular rearrangements or dissociations were observed by isoelectric focusing. Heterogeneity of the β-amylase enzymes of extracts of barley containing low concentrations of thiolated reducing agents (10 mM) may result from the occurrence of several forms of "free" β-amylase, from the existence of several soluble forms of protein-bound β-mylase, or from partial dissociation of large molecular weight aggregates of β-amylase. Further characterization of each component isolated by chromatofocusing is required to determine the interrelationships among the various β-amylase components.

Keywords: Barley, β-amylase, Chromatofocusing, Isoelectric focusing