Abstract
β-(1→4)-D-Glucanase(II) was isolated and purified to homogeneity on SDS-electrophoresis from brewing barley malt. This enzyme had an endo-hydrolase action pattern on β-glucan prepared from the same malt, while the enzyme formed precipitates in the reaction mixture. These precipitates (P-I) as a whole were composed of β -(1→3) and (1→4) linkages in a molar ratio of 27.6: 72.4. The P-I was separated into two parts and analyzed; they had mainly linear β-(1→4) linkages. When cellotetraose or 3-O-β-cellotriosyl-D-glucose was used as a substrate for β-(1→4)-D-glucanase(II), insoluble materials were similarly formed in reaction mixture. These water-insoluble materials were cellooctaose and 3-O-β-cellooctaosyl-D-glucose, respectively. These results suggest that β-(1→4)-D-glucanase(II) catalyzed the transfer of β-D-glucosyl residues from each oligosaccharide to C4-OH of the non-reducing residue in each of them, and the resulting products from the transglucosylation precipitated in the reaction mixture.
