Immunoelectrophoretic identification of a heterodimer β‐amylase in extracts of barley grain

Gel filtration followed by immunoelectrophoretic characterisation showed that approximately 30% of the β‐amylase activity in salt extracts of Emir barley grains was localised in a dimei complex (mol. wt. 95 000) between β‐amylase (mol. wt. 56 000) and a non‐active protein Z (mol. wt. 40 000). This complex seemed to be the only polymer β‐amylase present in 1 mM β‐mercaptoethanol extracts of barley and barley green malt. The complex was split by 100 mM β‐mercaptoethanol.