ABSTRACT
The major constituents of barley endosperm cell walls are the (1→3,1→4)-ß-glucans and arabinoxylans. Degradation of (1→3,1→4)-ß-glucan by (1→3)ß-glucanases probably depends on the presence of contiguous (1→3,1→4)-ß-glucosyl residues in the polysaccharide. Two (1→3,1→4)-ß-glucanases were ultimately purified approx. The synthesis of many of the hydrolytic enzymes responsible for endosperm mobilization in germinating barley occurs in the aleurone layer and is enhanced by the phytohormone gibberellic acid. One of the original objectives of the work described was simply to establish the number of (1→3,1→4)-ß-glucanases in germinating barley and, if more than one enzyme was indeed present, to purify them for comparison of their chemical and enzymic properties. Earlier attempts to purify the (1→3,1→4)-ß-glucanases of germinating barley led to some confusion as to the number of enzymes present; two were identified in extracts of "green malt" whereas only one enzyme could be detected in extracts of kiln-dried malt.
