[Endo-1,3-beta-glucanase from Actinomyces cellulosae]

Endo-1.3-beta-glucanase (EC 3.2.1.39) from Actinomyces cellulosae was purified 960-fold by ion-exchange chromatography on DEAE-cellulose and DEAE-Sephadex A-50 and by gel-filtration through Acrylex P-60. The enzyme was electrophoretically homogeneous and had molecular weight of about 30 000 as determined by polyacrylamide gel disc-electrophoresis in the presence of SDS and gel-filtration through Sephadex G-200. The isoelectric point lies at 4.0; the pH optimum for the non-purified enzyme preparation is 5.5, that for the purified one is 6.0. The enzyme is stable within the pH range of 7.0-8.0 and is rapidly inactivated in acid media. The enzyme does not hydrolyze laminaribiose, lichenane, barley glucan, pustulane, KM-cellulose, but splits laminarane to form high molecular weight oligosaccharides, a small number of low molecular weight oligosaccharides and a negligible amount of glucose. Studies with glucose oxidase showed that splitting of 1.3-beta-glucan results in a beta-form of glucose.