Grishutin Sergei G, Gusakov Alexander V, Dzedzyulya Ekaterina I, Sinitsyn Arkady P
Division of Chemical Enzymology, Department of Chemistry, M. V. Lomonosov Moscow State University, Moscow 119899, Russia.
Carbohydr Res. 2006 Feb 6;341(2):218-29. doi: 10.1016/j.carres.2005.11.011. Epub 2005 Dec 15.
Using anion-exchange chromatography on Source 15Q followed by hydrophobic interaction chromatography on Source 15 Isopropyl, a lichenase-like endo-(1-->4)-beta-glucanase (BG, 28kDa, pI4.1) was isolated from a culture filtrate of Aspergillus japonicus. The enzyme was highly active against barley beta-glucan and lichenan (263 and 267 U/mg protein) and had much lower activity toward carboxymethylcellulose (3.9 U/mg). The mode of action of the BG on barley beta-glucan and lichenan was studied in comparison with that of Bacillus subtilis lichenase and endo-(1-->4)-beta-glucanases (EG I, II, and III) of Trichoderma reesei. The BG behaved very similar to the bacterial lichenase, except the tri- and tetrasaccharides formed as the end products of beta-glucan hydrolysis with the BG contained the beta-(1-->3)-glucoside linkage at the non-reducing end, while the lichenase-derived oligosaccharides had the beta-(1-->3)-linkage at the reducing end. The BG was characterized by a high amino acid sequence identity to the EG of Aspergillus kawachii (UniProt entry Q12679) from a family 12 of glycoside hydrolases (96% in 162 identified aa residues out of total 223 residues) and also showed lower sequence similarity to the EglA of Aspergillus niger (O74705).
使用Source 15Q进行阴离子交换色谱，随后在Source 15异丙基上进行疏水相互作用色谱，从日本曲霉的培养滤液中分离出一种类地衣酶内切-(1→4)-β-葡聚糖酶（BG，28 kDa，pI 4.1）。该酶对大麦β-葡聚糖和地衣多糖具有高活性（分别为263和267 U/mg蛋白质），而对羧甲基纤维素活性低得多（3.9 U/mg）。将BG对大麦β-葡聚糖和地衣多糖的作用模式与枯草芽孢杆菌地衣酶以及里氏木霉的内切-(1→4)-β-葡聚糖酶（EG I、II和III）进行了比较研究。BG的行为与细菌地衣酶非常相似，只是BG水解β-葡聚糖形成的终产物三糖和四糖在非还原端含有β-(1→3)-糖苷键，而地衣酶产生的寡糖在还原端含有β-(1→3)-键。BG的特征是与来自糖苷水解酶家族12的河合曲霉EG（UniProt条目Q12679）具有高氨基酸序列同一性（在总共223个残基中162个已鉴定的氨基酸残基中有96%），并且与黑曲霉的EglA（O74705）也显示出较低的序列相似性。
