β-glucanase was purified from a solid-state culture of Trichoderma reesei on wheat bran in three steps which comprised ammonium sulfate precipitation, Sephadex G-100 chromatography, and DEAE-Sepha-dex A-50 chromatogr...β-glucanase was purified from a solid-state culture of Trichoderma reesei on wheat bran in three steps which comprised ammonium sulfate precipitation, Sephadex G-100 chromatography, and DEAE-Sepha-dex A-50 chromatography, rIlae molecular mass was determined to be 35.21 kilodahons by sodium dodecyl sulfate-12.5% polyacrylamide gel electrophoresis. The β-glucanase at low pHs was more stable than that at high pHs, and optimum pH was 5.0. The optimum temperature was 60℃, and β-glueanase was relatively stable at below 40° for 60min. The Km of the enzyme on β-glucan was 10.86 mg/ml, and the Vmax on β-glucanwas 14286 pmol of glucose equivalents per nag of the pure enzyme per rain. The β-glucanase activity was significantly inhibited by Fe^3+ ions, and was reduced in the presence of Cu^2+ ions, Mn^2+ ions and Mg^2+ ions at 5mmol/L and 10mmol/L, respectively. The β-glucanase activity was stimulated by Co^2+ ions, Ca^2 + ions,Zn^2+ ions, and Fe^2+ ions at 1mmol/L and 5mmol/L, respectively.展开更多
文摘β-glucanase was purified from a solid-state culture of Trichoderma reesei on wheat bran in three steps which comprised ammonium sulfate precipitation, Sephadex G-100 chromatography, and DEAE-Sepha-dex A-50 chromatography, rIlae molecular mass was determined to be 35.21 kilodahons by sodium dodecyl sulfate-12.5% polyacrylamide gel electrophoresis. The β-glucanase at low pHs was more stable than that at high pHs, and optimum pH was 5.0. The optimum temperature was 60℃, and β-glueanase was relatively stable at below 40° for 60min. The Km of the enzyme on β-glucan was 10.86 mg/ml, and the Vmax on β-glucanwas 14286 pmol of glucose equivalents per nag of the pure enzyme per rain. The β-glucanase activity was significantly inhibited by Fe^3+ ions, and was reduced in the presence of Cu^2+ ions, Mn^2+ ions and Mg^2+ ions at 5mmol/L and 10mmol/L, respectively. The β-glucanase activity was stimulated by Co^2+ ions, Ca^2 + ions,Zn^2+ ions, and Fe^2+ ions at 1mmol/L and 5mmol/L, respectively.
