Abstract
An exo-β-1, 3-glucanase was purified from the commercial enzyme preparation "Kitalase" which is a yeast cell wall lytic enzyme preparation. The purification procedures consisted of following steps: ammonium sulfate fraction, SP-Sephadex C-50 and CM-Cellulose C-32 column chromatography, and Sephadex G-100 gel filtration. The optimum pH value was 5.8, and the optimum temperature was 55°C. The enzyme was stable in the pH range of 5.1 to 9.8 and at temperatures below 53°C. The isoelectric point and the molecular weight were estimated to be pH 9.3 and 73000, respectively. The enzyme was shown to bypass β-1, 6-linkaged branches to cleave β-1, 3-linkages when scleroglucan was used as substrate. The Km values for laminarin, laminaripentaose, laminaritetraose and laminaritriose were 0.16, 2.01, 2.24 and 1.34 mM, respectively.
