Abstract
β-(1→4)-D-glucanase (I) was isolated and purified to homogeneity by SDS-gel electrophoresis from brewing malt. The enzyme had an endo-hydrolase action pattern against β-glucan and carboxymethyl cellulose, while it formed precipitates having mainly linear β-(1→4) linkages in the reaction against β-glucan. The enzyme catalyzed the reaction transferring the non-reducing end cellobiose or cellotriose moiety of cellopentaose to the non-reducing end glucosyl residue of cellopentaose, and the resulting reducing end cellotriose, cellobiose, and precipitates were detected in the reaction mixture. The precipitates were found to be a linear β-(1→4) linked glucan having an average degree of polymerization of 10. These results indicated that β-(1→4)-D-glucanase (I) had a strict specificity of forming β-(1→4) linkages and had a capacity to elongate the linkage to a higher extent.
