Horikoshi K, Atsukawa Y
Biochim Biophys Acta. 1975 Apr 19;384(2):477-83. doi: 10.1016/0005-2744(75)90048-0.
A 1, 3-beta-glucanase of Bacillus No. 221 has been extensively purified by a DEAE-cellulose column followed by a Sephadex G-75 gel filtration, and crystallized in ammonium sulfate solution. The crystalline enzyme is homogenous on the basis of polyacrylamide gel electrophoresis, sedimentation in ultracentrifuge (3.2 S), Ampholine electrofocusing (pI=4.1) and dodecylsulfate-polyacrylamide gel electrophoresis (Mr=36 000). The enzyme has an optimum pH for enzyme action at 8.5 which is higher than those of other 1, 3-beta-glucanases so far reported. The enzyme is very thermostable; about 90% of activity remains after being heated at 70 degrees C for 10 min, and no effect of Ca-2's obversed. The enzyme does not hydrolyse laminaritriose, but hydrolyses laminaritetraose, and yields glucose and laminaritriose. The enzyme splits laminaran at random and yields glucose, laminaribiose, laminaritriose and higher oligosaccharides. From these results, this enzyme is a type of endo-1, 3-beta-glucanase.
221号芽孢杆菌的一种1,3-β-葡聚糖酶先用DEAE-纤维素柱进行了广泛纯化，然后经Sephadex G-75凝胶过滤，并在硫酸铵溶液中结晶。基于聚丙烯酰胺凝胶电泳、超速离心沉降（3.2 S）、两性电解质等聚焦电泳（pI = 4.1）和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（Mr = 36 000），结晶酶是均一的。该酶作用的最适pH为8.5，高于迄今报道的其他1,3-β-葡聚糖酶。该酶非常耐热；在70℃加热10分钟后仍保留约90%的活性，且未观察到Ca2+的影响。该酶不水解层叠三糖，但能水解层叠四糖，并产生葡萄糖和层叠三糖。该酶随机切割海带多糖，产生葡萄糖、层叠二糖、层叠三糖和更高的寡糖。根据这些结果，该酶是一种内切-1,3-β-葡聚糖酶。
