Unite Enzyme and Bioconversion, Ecole Nationale d'Ingénieurs de Sfax, Route Soukra km 3.5 B.P.W, 3038 Sfax, Tunisia.
Appl Biochem Biotechnol. 2010 Feb;160(4):1227-40. doi: 10.1007/s12010-009-8630-z. Epub 2009 May 6.
The highest beta-mannanase activity was produced by Penicillium occitanis Pol6 on flour of carob seed, whereas starch-containing medium gave lower enzymes titles. The low molecular weight enzyme was purified to homogeneity by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography procedures. The purified beta-mannanase (ManIII) has been identified as a glycoprotein (carbohydrate content 5%) with an apparent molecular mass of 18 kDa. It was active at 40 degrees C and pH 4.0. It was stable for 30 min at 70 degrees C and has a broad pH stability (2.0-12.0). ManIII showed K (m), V (max), and K (cat) values of 17.94 mg/ml, 93.52 U/mg, and 28.13 s(-1) with locust bean gum as substrate, respectively. It was inhibited by mannose with a K (I) of 0.610(-3) mg/ml. ManIII was activated by CuSO4 and CaCl2 (2.5 mM). However, in presence of 2.5 mM Co2+, its activity dropped to 60% of the initial activity. Both N-terminal and internal amino acid sequences of ManIII presented no homology with mannanases of glycosides hydrolases. During incubation with locust bean gum and Ivory nut mannan, the enzyme released mainly mannotetraose, mannotriose, and mannobiose.
β-甘露聚糖酶活性最高的是 Penicillium occitanis Pol6 在角豆种子面粉上产生的，而含淀粉的培养基则产生较低的酶活。通过硫酸铵沉淀、凝胶过滤和离子交换层析等步骤，可将低分子量的酶纯化为均一性。纯化的β-甘露聚糖酶（ManIII）已被鉴定为一种糖蛋白（碳水化合物含量为 5%），表观分子量为 18 kDa。它在 40°C 和 pH 4.0 时具有活性。在 70°C 下稳定 30 分钟，具有较宽的 pH 稳定性（2.0-12.0）。ManIII 以槐豆胶为底物时，表现出 K（m）、V（max）和 K（cat）值分别为 17.94 mg/ml、93.52 U/mg 和 28.13 s（-1）。它被甘露糖抑制，K（I）为 0.610（-3）mg/ml。ManIII 被 CuSO4 和 CaCl2（2.5 mM）激活。然而，在存在 2.5 mM Co2+的情况下，其活性降至初始活性的 60%。ManIII 的 N 末端和内部氨基酸序列与糖苷水解酶的甘露聚糖酶没有同源性。在与槐豆胶和象牙椰子甘露聚糖孵育期间，该酶主要释放甘露四糖、甘露三糖和甘露二糖。
